The paper analyzes the change trend of Hubei province grain price and its influence on CPI, based on data from1990-2014. The analysis results show that the grain price goes through a change of early rising and later r...The paper analyzes the change trend of Hubei province grain price and its influence on CPI, based on data from1990-2014. The analysis results show that the grain price goes through a change of early rising and later reducing during1990-2014, and smoothly fluctuated in recent years with a downward trend; grain price and CPI fluctuations have a consistent trend, but the grain price volatility is ahead of CPI fluctuation; grain price has positive influences on the CPI; there is a longterm equilibrium relationship between them, namely,grain price is a significant cause of CPI fluctuation. Therefore, we should take various measures to stabilize grain price in order to stabilize the CPI.展开更多
In order to better ensure the food security in China,this paper explores the grain scale management mode in Hubei Province. It analyzes the grain production situation in Hubei Province as well as the existing scale ma...In order to better ensure the food security in China,this paper explores the grain scale management mode in Hubei Province. It analyzes the grain production situation in Hubei Province as well as the existing scale management mode,and according to the main mode of grain scale management in Hubei Province and the main problems,it puts forward related recommendations to improve the productivity of grain and promote the development of Hubei's grain scale management.展开更多
Drought stress is one of the most severe environmental constraints to plant growth and crop productivity. Plant growth is greatly affected by drought stress, and plants, to survive,adapt to this stress by invoking dif...Drought stress is one of the most severe environmental constraints to plant growth and crop productivity. Plant growth is greatly affected by drought stress, and plants, to survive,adapt to this stress by invoking different pathways. Piriformospora indica, a root-colonizing endophytic fungus of Sebacinales, promotes plant growth and confers resistance to biotic and abiotic stresses, including drought stress, by affecting the physiological properties of the host plant. The fungus strongly colonizes the roots of maize(Zea mays L.) and promotes shoot and root growth under both normal growth conditions and drought stress. We used polyethylene glycol(PEG-6000) to mimic drought stress and found that root fresh and dry weight, leaf area, SPAD value, and leaf number were increased in P. indica-colonized plants.The antioxidative activities of catalases and superoxide dismutases were upregulated within 24h in the leaves of P. indica-colonized plants. Drought-related genes DREB2A, CBL1,ANAC072, and RD29A were upregulated in drought-stressed leaves of P. indica-colonized plants. Furthermore, after drought treatment, proline content increased, whereas accumulation of malondialdehyde(MDA), an indicator of membrane damage, decreased in P. indica-colonized maize. We conclude that P. indica-mediated plant protection against the detrimental effects of drought may result from enhanced antioxidant enzyme activity,proline accumulation, and expression of drought-related genes and lower membrane damage in maize plants.展开更多
To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNram...To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNramp5 mutants(nramp5×7 and nramp5×9) were evaluated for grain Cd accumulation and agronomic performances. In paddy field soil containing approximately 0.9 mg/kg Cd, lct1×1 grains contained approximately 40%(0.17 mg/kg) of the Cd concentration of the wild type parental line, less than the China National Food Safety Standard(0.20 mg/kg). Both OsNramp5 mutants showed low grain Cd accumulation(< 0.06 mg/kg) in the paddy(approximately 0.9 mg/kg Cd) or in pots in soil spiked with 2 mg/kg Cd. However, only nramp5×7 showed normal growth and yield, whereas the growth of nramp5×9 was severely impaired. The study showed that lct1×1 could be used to produce rice grains safe for human consumption in lightly contaminated paddy soils and nramp5×7 used in soils contaminated by much higher levels of Cd.展开更多
Wheat seed development is an important physiological process of seed maturation and directly affects wheat yield and quality. In this study, we performed dynamic transcriptome microarray analysis of an elite Chinese b...Wheat seed development is an important physiological process of seed maturation and directly affects wheat yield and quality. In this study, we performed dynamic transcriptome microarray analysis of an elite Chinese bread wheat cultivar(Jimai 20) during grain development using the Gene Chip Wheat Genome Array. Grain morphology and scanning electron microscope observations showed that the period of 11–15 days post-anthesis(DPA) was a key stage for the synthesis and accumulation of seed starch. Genome-wide transcriptional profiling and significance analysis of microarrays revealed that the period from 11 to 15 DPA was more important than the 15–20 DPA stage for the synthesis and accumulation of nutritive reserves.Series test of cluster analysis of differential genes revealed five statistically significant gene expression profiles. Gene ontology annotation and enrichment analysis gave further information about differentially expressed genes, and Map Man analysis revealed expression changes within functional groups during seed development. Metabolic pathway network analysis showed that major and minor metabolic pathways regulate one another to ensure regular seed development and nutritive reserve accumulation. We performed gene co-expression network analysis to identify genes that play vital roles in seed development and identified several key genes involved in important metabolic pathways. The transcriptional expression of eight key genes involved in starch and protein synthesis and stress defense was further validated by q RT-PCR. Our results provide new insight into the molecular mechanisms of wheat seed development and the determinants of yield and quality.展开更多
There are 41 members of the CCT(CO, CO-like, and TOC1) domain-containing gene family in rice, which are divided into three subfamilies: COL(CONSTANS-like), CMF(CCT motif family), and PRR(pseudoresponse regula...There are 41 members of the CCT(CO, CO-like, and TOC1) domain-containing gene family in rice, which are divided into three subfamilies: COL(CONSTANS-like), CMF(CCT motif family), and PRR(pseudoresponse regulator). The first flowering gene to be isolated by map-based cloning, Heading date 1(Hd1), which is the orthologue of CO in rice, belongs to COL. The central regulator of plant development, Ghd7, belongs to CMF. The major role in controlling rice distribution to high latitudes, Ghd7.1/PRR37, belongs to PRR. Both of Hd1, Ghd7 and Ghd7.1 simultaneously control grain number, plant height, and the heading date. To date, 13 CCT family genes from these three subfamilies have been shown to regulate flowering. Some of them have pleiotropic effects on grain yield, plant height, and abiotic stresses, and others function as circadian oscillators. There are two independent photoperiod flowering pathways that are mediated by GI-Hd1-Hd3 a/RFT and GI-Ehd1-Hd3 a/RFT in rice. CCT family genes are involved in both pathways. The latest study reveals that protein interaction between Hd1 and Ghd7 integrates the two pathways. CCT family genes are rich in natural variation because rice cultivars have been subjected to natural and artificial selection for different day lengths in the process of domestication and improvement. Alleles of several crucial CCT family genes such as Hd1, Ghd7, and Ghd7.1 exhibit geographic distribution patterns and are highly associated with yield potentials. In addition, CCT family genes are probably involved in the responses to abiotic stress, which should be emphasized in future work. In general, CCT family genes play important roles in regulating flowering, plant growth, and grain yield. The functional identification and elucidation of the molecular mechanisms of CCT family genes would help construct a flowering regulatory network and maximize their contribution to rice production.展开更多
Non-specific lipid transfer proteins(nsLTPs/LTPs) that can transport various phospholipids across the membrane in vitro are widespread in the plant kingdom, and they play important roles in many biological processes t...Non-specific lipid transfer proteins(nsLTPs/LTPs) that can transport various phospholipids across the membrane in vitro are widespread in the plant kingdom, and they play important roles in many biological processes that are closely related to plant growth and development. Recently, nsLTPs have been shown to respond to different forms of abiotic stresses. Despite the vital roles of nsLTPs in many plants, little is known about the nsLTPs in wheat. In this study, 330 nsLTP proteins were identified in wheat and they clustered into five types(1, 2, c, d, and g) by phylogenetic analysis with the nsLTPs from maize, Arabidopsis, and rice. The wheat nsLTPs of type d included three subtypes(d1, d2, and d3) and type g included seven subtypes(g1–g7). Genetic structure and motif pattern analyses showed that members of each type had similar structural composition. Moreover, GPI-anchors were found to exist in non-g type members from wheat for the first time. Chromosome mapping revealed that all five types were unevenly and unequally distributed on 21 chromosomes. Furthermore, gene duplication events contributed to the proliferation of the nsLTP genes. Large-scale data mining of RNA-seq data covering multiple growth stages and numerous stress treatments showed that the transcript levels of some of the nsLTP genes could be strongly induced by abiotic stresses, including drought and salinity, indicating their potential roles in mediating the responses of the wheat plants to these abiotic stress conditions. These findings provide comprehensive insights into the nsLTP family members in wheat, and offer candidate nsLTP genes for further studies on their roles in stress resistance and potential for improving wheat breeding programs.展开更多
Stigma exsertion in male sterile lines of hybrid rice is important for seed yield.In the present study, ZS616 [Oryza sativa subsp.Xian(indica)], a male sterile line with a stigma exsertion rate(SER) as high as 94.5%, ...Stigma exsertion in male sterile lines of hybrid rice is important for seed yield.In the present study, ZS616 [Oryza sativa subsp.Xian(indica)], a male sterile line with a stigma exsertion rate(SER) as high as 94.5%, was crossed to DS552, a japonica line with almost no exserted stigmas.F3 plants with extremely low and high SER were sequenced to identify SER-associated quantitative trait loci(QTL).A major QTL for SER, qSER-3.1, was identified along with other QTL on chromosome 3 in a 3.9 Mb region.A total of 307 nonsynonymous single-nucleotide polymorphisms(SNPs) and 27 frame-shift insertion/deletions(InDels)differentiating ZS616 and DS552 were identified in the region containing qSER-3.1.Most SNPs(294) and InDels(25) were excluded after further analysis because they were shared by ZS616 and low(<2.0%) SER accessions in the Huazhong Agricultural University(HAU) core rice collection.Association analysis using the full HAU collection identified a 17-bp InDel in OS03 G0689400 as the most likely causal genetic variant underlying qSER-3.1.ZS616-type accessions(n = 54, with the 17-bp insertion) in the HAU collection had minimum(16.5%)and mean(39.6%) SERs significantly greater than those(n = 424) without the insertion(with minimum and mean SERs of 0.2% and 20.6%, respectively).Thus, this study identified a major QTL for stigma exsertion and revealed the mutation in a candidate gene for the QTL.展开更多
Environmental conditions greatly affect the growth of rice. To investigate the geographic differences in yield formation of single-season high-yielding hybrid rice in southern China, experiments were conducted in 2017...Environmental conditions greatly affect the growth of rice. To investigate the geographic differences in yield formation of single-season high-yielding hybrid rice in southern China, experiments were conducted in 2017 and 2018 in the upper and middle–lower reaches of the Yangtze River with 10–30 main locally planted high-yielding hybrid cultivars used as materials. Compared with rice planted in the middle–lower reaches of the Yangtze River, rice planted in the upper reaches has a longer tillering duration, higher accumulated temperature(≥10℃) during tillering period, but lower accumulated temperature and solar radiation from initial booting to maturity. Yield traits comparison between the upper and the middle–lower reaches of Yangtze River showed that the former had 48.1% more panicles per unit area while the latter had 46.4% more grains per panicle;the rice yield in the former was positively correlated with the seed setting rate and the dry matter accumulation before heading, while the latter was positively correlated with grains per panicle and dry matter accumulation from booting to maturity. Comparison of the same variety Tianyouhuazhan planted in different regions showed there was a significant positive correlation between panicle number and the duration of and accumulated temperature during the tillering period(r=0.982^(**), r=0.993^(**), respectively), and between grains per panicle and accumulated solar radiation during booting period(r=0.952~*). In the upper reaches of the Yangtze River, more than 90% of cultivars with an yield of greater than 11 t ha^(–1) had an effective panicle number of 250–340 m^(–2), and there was a significant negative correlation between seed setting rate and grains per panicle;therefore, the high-yielding rice production in these regions with a long effective tillering period(>40 d) should choose varieties with moderate grains per panicle, adopt crop managements such as good fertilizer and water measures during vegetative growth period to ensure a certain number of effective panicles, and to increase the dry matter accumulation before heading. While in regions with a short effective tillering period(<20 d) but good sunshine conditions during the reproductive growth period, such as the middle–lower reaches of the Yangtze River, high-yielding rice production should choose cultivars with large panicles, adopt good water and fertilizer managements during the reproductive growth period to ensure the formation of large panicles and the increase of dry matter accumulation after heading.展开更多
The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly...The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly investigated.This study uses a survey in 2016 and a field experiment in 2017 in Qianjiang,Hubei Province,China to assess the relative economics of concurrent rice-wheat(RW),rice-crayfish(RC),and crayfish monoculture(CM)models in waterlogged land areas.Thefield survey indicated that the RC model had a higher benefit-cost ratio(3.5:1)than the RW(2.0:1)and CM(3.1:1)models and the RC model protected farmers’enthusiasm for grain production facing unfavourable weather conditions.The field experiment aimed to explore nitrogen management strategies in RC fields.In the experiment,four levels of nitrogen concentration gradient-0 kg N ha^(-1)(0 N),75 kg N ha^(-1)(75 N),150 kg N ha^(-1)(150 N)and 225 kg N ha^(-1)(225 N),were set in a 2-year-old rice-crayfish(RC2)field,an 8-year-old rice-crayfish(RC8)field,and a RWfield as a control.Thefield experiment results suggested that the peak rice yield in RW,RC2,and RC8 occurred when 225 N,150 N and 75 N were used,respectively.In RC2 and RC8,however,residual feed-nitrogen that was not used by crayfish was utilized by rice plants.Thus,an optimal amount of nitrogen in RCfields was proposed to improve the nitrogen use efficiency and reduce environmental pollution by nitrogen fertilizer.Farmers use less nitrogen but have higher net income in RC than in RW and CM.It is necessary to sustainably develop integrated farming technologies(i.e.,properfield configurations for ricefields)to effectively sustain rice production.The results also showed that the RC farming model was a viable diversification option for rice farmers in waterlogged land.展开更多
The rice cultivars carrying dep1(dense and erect panicle 1)have the potential to achieve both high grain yield and high nitrogen use efficiency(NUE).However,few studies have focused on the agronomic and physiological ...The rice cultivars carrying dep1(dense and erect panicle 1)have the potential to achieve both high grain yield and high nitrogen use efficiency(NUE).However,few studies have focused on the agronomic and physiological performance of those cultivars associated with high yield and high NUE under field conditions.Therefore,we evaluated the yield performance and NUE of two near-isogenic lines(NILs)carrying DEP1(NIL-DEP1)and dep1-1(NIL-dep1)genes under the Nanjing 6 background at 0 and 120 kg N ha^(–1).Grain yield and NUE for grain production(NUEg)were 25.5 and 21.9%higher in NIL-dep1 compared to NIL-DEP1 averaged across N treatments and planting years,respectively.The yield advantage of NIL-dep1 over NIL-DEP1 was mainly due to larger sink size(i.e.,higher total spikelet number),grainfilling percentage,total dry matter production,and harvest index.N utilization rather than N uptake contributed to the high yield of NIL-dep1.Significantly higher NUEg in NIL-dep1 was associated with higher N and dry matter translocation efficiency,lower leaf and stem N concentration at maturity,and higher glutamine synthetase(GS)activity in leaves.In conclusion,dep1 improved grain yield and NUE by increasing N and dry matter transport due to higher leaf GS activity under field conditions during the grain-filling period.展开更多
Haynaldia villosa(2n=14,VV),a wild grass of the subtribe Triticeae,serves as potential gene resources for wheat genetic improvement.In this study,the proteome characterization during grain development of Yangmai 5 and...Haynaldia villosa(2n=14,VV),a wild grass of the subtribe Triticeae,serves as potential gene resources for wheat genetic improvement.In this study,the proteome characterization during grain development of Yangmai 5 and Yangmai 5-H.villosa 6VS/6AL translocation line was investigated by a comparative proteomic approach.Two-dimensional electrophoresis identified 81 differentially accumulated proteins(DAPs)during five grain developmental stages in wheat-H.villosa translocation line.These proteins were mainly involved in stress defense,storage protein,energy metabolism,protein metabolism and folding,carbon metabolism,nitrogen metabolism,and starch metabolism.In particular,6VS/6AL translocation led to significant upregulation of 36 DAPs and specific expression of 11 DAPs such as chitinase,thaumatin-like proteins,glutathione transferase,α-amylase inhibitor,heat shock proteins,and betaine aldehyde dehydrogenase.These proteins mainly involved in biotic and abiotic stress responses.Further analysis found that the upstream 1500 promoter regions of these stress-responsive DAP genes contained multiple high-frequency cis-acting elements related to stress defense such as abscisic acid response element ABRE,methyl jasmonate(MeJA)-response element TGACG-motif and CGTCA-motif involved in oxidative stress and antioxidant response element(ARE).RNA-seq and RT-qPCR analyses revealed the high expression of these stress-defensive DAP genes in the developing grains,particularly at the early-middle grain filling stages.Our results demonstrated that 6VS chromosome of H.villosa contains abundant stress-defensive proteins that have potential values for wheat genetic improvement.展开更多
In order to investigate effects of topdressing on grain yield and N use efficiency of mechanically-transplanted hybrid rice, this experiment was conducted with 2-line hybrid rice cultivars, Quanliangyou 1 and Quanlian...In order to investigate effects of topdressing on grain yield and N use efficiency of mechanically-transplanted hybrid rice, this experiment was conducted with 2-line hybrid rice cultivars, Quanliangyou 1 and Quanliangyou 681 with 3 application levels of N fertilizer, N_0, N_1, N_2, respectively. The results showed that there were no significant differences in grain yields of the 2 varieties between treatments N_1 and N_2. It was indicated that N is not the factor which could limit grain yield within limited application levels of N fertilizer. High N fertilizer treatment could contribute to the formation of effective panicles and spikelets per panicle, but it could also lead to the decline in grain filling rate. It was suggested that lowering the amount of Nfertilizer could facilitate improvement of N-use efficiency.展开更多
Land,the foundation of agriculture and farmers,is the most basic capital goods of agricultural production. Confirmation of land right in rural areas not only effectively protects the land contract management right of ...Land,the foundation of agriculture and farmers,is the most basic capital goods of agricultural production. Confirmation of land right in rural areas not only effectively protects the land contract management right of peasants and helps to realize the informatization management of land contract,but also lays a foundation for land circulation and scale management. In addition,it also promotes the realization of agricultural modernization. This paper analyzes the problems in the confirmation of land right and sets forth recommendations under the premise of realizing the importance of confirmation of land right.展开更多
In the economic new normal,production of hybrid rice seed in foreign countries is the necessity for reducing farmland area occupied by seed production,for ensuring national grain security,realizing cost reducing and q...In the economic new normal,production of hybrid rice seed in foreign countries is the necessity for reducing farmland area occupied by seed production,for ensuring national grain security,realizing cost reducing and quality improving of hybrid rice seed,strengthening competitive power at international market,guiding seed industry of China to go out,building transnational seed groups with core competitive power,establishing close relationship with developing countries,promoting the construction of One Belt One Road strategy,serving overall situation of diplomacy,and setting up excellent international image. It is feasible to produce hybrid seed in foreign countries considering( i) high overall national strength of China,( ii) rapid and healthy growth of China's seed industry and increasingly mature hybrid rice seed production technologies,( iii) excellent climatic conditions of foreign host countries of seed production,and( iv) low land and labor price of foreign host countries of seed production. However,there are social and policy risks,technology and trade barrier risks,market,production,and other risks for production of hybrid rice seed in foreign countries. In view of these,it came up with recommendations,including allowing delivering parent seeds of hybrid rice to foreign countries,allowing delivering hybrid rice seed to China,solving the problem of " opening in protection,and protection in opening",and formulating a package of support policies.展开更多
Cytokinins(CKs)function in plant development and during stress responses,but their role in drought tolerance in wheat is unknown.In the present study,24 isopentenyltransferase(IPT)genes,encoding ratelimiting enzymes i...Cytokinins(CKs)function in plant development and during stress responses,but their role in drought tolerance in wheat is unknown.In the present study,24 isopentenyltransferase(IPT)genes,encoding ratelimiting enzymes in CK biosynthesis were identified in the wheat genome.The chromosomal locations and structures of the genes,protein properties,and phylogenetic relationships were characterized.ATP/ADP TaIPT genes showed tissue-specific expression.TaIPT2,TaIPT7,and TaIPT8 expression was rapidly induced by 0.5–1 h drought treatments,which decreased to low levels after 2 h drought treatment,as did most other TaIPT genes.TaIPT8-5a/5b/5d triple mutants showed decreased levels of tZtype CK under normal and drought conditions and reduced drought tolerance,which,however,did not manifest as phenotype alterations.By contrast,transgenic wheat plants with drought-induced TaIPT8showed increased drought tolerance.Our study provides a foundation for further investigation of TaIPT genes and novel insights into the role of CKs in the drought response of wheat.展开更多
Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was per...Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F_(2) population derived from two landraces: Chuan 7(C7) and Haoboka(HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F_(2) population of 940 plants to construct low-and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F_(2) population or BC_(4)F_(2) populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1(sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture.展开更多
Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, th...Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.展开更多
Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present stu...Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present study, large phenotypic variation was observed in 760 accessions from the 3 K Rice Genomes Project for both appearance quality and cooked rice elongation. Most component traits of appearance quality and cooked rice elongation showed significant pairwise correlations, but a low correlation was found between appearance quality and cooked rice elongation. A genome-wide association study identified 74 QTL distributed on all 12 chromosomes for grain length, grain width, length to width ratio, degree of endosperm with chalkiness, rice elongation difference, and elongation index. Thirteen regions containing QTL stably expressed in multiple environments and/or exerting pleiotropic effects on multiple traits were detected. By gene-based association analysis and haplotype analysis, 46 candidate genes, including five cloned genes, and 49 favorable alleles were identified for these 13 QTL. The effect of the candidate gene Wx on rice elongation difference was validated by a transgenic strategy. These results shed light on the genetic bases of appearance quality and cooked rice elongation and provide gene resources for improving rice quality by molecular breeding.展开更多
Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM1...Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM102)and‘Yangmai158’(YM158)were planted to study the dynamic changes of photosynthetic characteristics in flag leaf and the influence of waterlogging at anthesis on the yield and components and dry matter accumulation and remobilization of winter wheat in above ground.The results showed that the SPAD values slightly increased at 1 day after anthesis(d),and then kept decreasing with the increase of waterlogging time.The decrease in SPAD value was more remarkably in YM158 than that in JM102.As for the chlorophyll fluorescence parameters,the photochemical efficiency(Fv/Fm),potential activity(Fv/Fo)of photosystem II,and electronic transmission(Fm/Fo)on photosystem II increased first and then decreased with the increase of waterlogging days after anthesis.The quantum ratio of heat dissipation(Fo/Fm)had a tendency opposite to that of Fv/Fm,and the change range of JM102 was lower than that of YM158.For the grain yield and components,waterlogging at anthesis decreased the dry weight of single stem,grain yield,1 000-kernel weight,spikelet per panicle,and harvest index,and the reduction of JM102 was smaller than that of YM158.As for the accumulation and remobilization of dry matter,the accumulation of dry matter after anthesis decreased significantly under waterlogging condition(WL),and the reduction of JM102 was smaller than that of YM158.In conclusion,waterlogging at anthesis significantly affected the photosynthetic characteristics,yield and components in both varieties,but different varieties exhibited different tolerances to waterlogging stress and YM158 was more sensitive to water stress than JM102.展开更多
基金Humanities and Social Sciences Department of education of Hubei Province Key Projects(15D024)Phased Research ResultsOpen fund general program from Hubei Collaborative Innovation Centre for Grain Industry(MS2015004)
文摘The paper analyzes the change trend of Hubei province grain price and its influence on CPI, based on data from1990-2014. The analysis results show that the grain price goes through a change of early rising and later reducing during1990-2014, and smoothly fluctuated in recent years with a downward trend; grain price and CPI fluctuations have a consistent trend, but the grain price volatility is ahead of CPI fluctuation; grain price has positive influences on the CPI; there is a longterm equilibrium relationship between them, namely,grain price is a significant cause of CPI fluctuation. Therefore, we should take various measures to stabilize grain price in order to stabilize the CPI.
基金Supported by Key Humanities and Social Sciences Project of Hubei Provincial Department of Education(15D024)Open Funding Project of Hubei Collaborative Innovation Center for Grain Industry(MS2015004)
文摘In order to better ensure the food security in China,this paper explores the grain scale management mode in Hubei Province. It analyzes the grain production situation in Hubei Province as well as the existing scale management mode,and according to the main mode of grain scale management in Hubei Province and the main problems,it puts forward related recommendations to improve the productivity of grain and promote the development of Hubei's grain scale management.
基金supported by the National Natural Science Foundation of China(No.31471496)
文摘Drought stress is one of the most severe environmental constraints to plant growth and crop productivity. Plant growth is greatly affected by drought stress, and plants, to survive,adapt to this stress by invoking different pathways. Piriformospora indica, a root-colonizing endophytic fungus of Sebacinales, promotes plant growth and confers resistance to biotic and abiotic stresses, including drought stress, by affecting the physiological properties of the host plant. The fungus strongly colonizes the roots of maize(Zea mays L.) and promotes shoot and root growth under both normal growth conditions and drought stress. We used polyethylene glycol(PEG-6000) to mimic drought stress and found that root fresh and dry weight, leaf area, SPAD value, and leaf number were increased in P. indica-colonized plants.The antioxidative activities of catalases and superoxide dismutases were upregulated within 24h in the leaves of P. indica-colonized plants. Drought-related genes DREB2A, CBL1,ANAC072, and RD29A were upregulated in drought-stressed leaves of P. indica-colonized plants. Furthermore, after drought treatment, proline content increased, whereas accumulation of malondialdehyde(MDA), an indicator of membrane damage, decreased in P. indica-colonized maize. We conclude that P. indica-mediated plant protection against the detrimental effects of drought may result from enhanced antioxidant enzyme activity,proline accumulation, and expression of drought-related genes and lower membrane damage in maize plants.
基金supported by the Zhejiang Provincial S & T Project on Breeding of Agricultural (Food) Crops (Grant No. 2016C02050-2)
文摘To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNramp5 mutants(nramp5×7 and nramp5×9) were evaluated for grain Cd accumulation and agronomic performances. In paddy field soil containing approximately 0.9 mg/kg Cd, lct1×1 grains contained approximately 40%(0.17 mg/kg) of the Cd concentration of the wild type parental line, less than the China National Food Safety Standard(0.20 mg/kg). Both OsNramp5 mutants showed low grain Cd accumulation(< 0.06 mg/kg) in the paddy(approximately 0.9 mg/kg Cd) or in pots in soil spiked with 2 mg/kg Cd. However, only nramp5×7 showed normal growth and yield, whereas the growth of nramp5×9 was severely impaired. The study showed that lct1×1 could be used to produce rice grains safe for human consumption in lightly contaminated paddy soils and nramp5×7 used in soils contaminated by much higher levels of Cd.
基金financially supported by grants from the National Natural Science Foundation of China(31471485)Natural Science Foundation of Beijing Citythe Key Developmental Project of Science and Technology from Beijing Municipal Commission of Education(KZ201410028031)
文摘Wheat seed development is an important physiological process of seed maturation and directly affects wheat yield and quality. In this study, we performed dynamic transcriptome microarray analysis of an elite Chinese bread wheat cultivar(Jimai 20) during grain development using the Gene Chip Wheat Genome Array. Grain morphology and scanning electron microscope observations showed that the period of 11–15 days post-anthesis(DPA) was a key stage for the synthesis and accumulation of seed starch. Genome-wide transcriptional profiling and significance analysis of microarrays revealed that the period from 11 to 15 DPA was more important than the 15–20 DPA stage for the synthesis and accumulation of nutritive reserves.Series test of cluster analysis of differential genes revealed five statistically significant gene expression profiles. Gene ontology annotation and enrichment analysis gave further information about differentially expressed genes, and Map Man analysis revealed expression changes within functional groups during seed development. Metabolic pathway network analysis showed that major and minor metabolic pathways regulate one another to ensure regular seed development and nutritive reserve accumulation. We performed gene co-expression network analysis to identify genes that play vital roles in seed development and identified several key genes involved in important metabolic pathways. The transcriptional expression of eight key genes involved in starch and protein synthesis and stress defense was further validated by q RT-PCR. Our results provide new insight into the molecular mechanisms of wheat seed development and the determinants of yield and quality.
基金supported by the National Key Research and Development Program of China (2016YFD0100301)
文摘There are 41 members of the CCT(CO, CO-like, and TOC1) domain-containing gene family in rice, which are divided into three subfamilies: COL(CONSTANS-like), CMF(CCT motif family), and PRR(pseudoresponse regulator). The first flowering gene to be isolated by map-based cloning, Heading date 1(Hd1), which is the orthologue of CO in rice, belongs to COL. The central regulator of plant development, Ghd7, belongs to CMF. The major role in controlling rice distribution to high latitudes, Ghd7.1/PRR37, belongs to PRR. Both of Hd1, Ghd7 and Ghd7.1 simultaneously control grain number, plant height, and the heading date. To date, 13 CCT family genes from these three subfamilies have been shown to regulate flowering. Some of them have pleiotropic effects on grain yield, plant height, and abiotic stresses, and others function as circadian oscillators. There are two independent photoperiod flowering pathways that are mediated by GI-Hd1-Hd3 a/RFT and GI-Ehd1-Hd3 a/RFT in rice. CCT family genes are involved in both pathways. The latest study reveals that protein interaction between Hd1 and Ghd7 integrates the two pathways. CCT family genes are rich in natural variation because rice cultivars have been subjected to natural and artificial selection for different day lengths in the process of domestication and improvement. Alleles of several crucial CCT family genes such as Hd1, Ghd7, and Ghd7.1 exhibit geographic distribution patterns and are highly associated with yield potentials. In addition, CCT family genes are probably involved in the responses to abiotic stress, which should be emphasized in future work. In general, CCT family genes play important roles in regulating flowering, plant growth, and grain yield. The functional identification and elucidation of the molecular mechanisms of CCT family genes would help construct a flowering regulatory network and maximize their contribution to rice production.
基金supported by the National Transgenic Key Project of the Ministry of Agriculture of China(2018ZX0800909B)the Major Program of Technological Innovation of Hubei Province,China(2018ABA085)+1 种基金the Open Project Program of Engineering Research Center of Ecology and Agricultural Use of Wetland,Ministry of Education,China(KF201802)the Southwest Agricultural Crop Pest Management Key Laboratory Open Fund of Ministry of Agriculture,China(2018-XNZD-01)。
文摘Non-specific lipid transfer proteins(nsLTPs/LTPs) that can transport various phospholipids across the membrane in vitro are widespread in the plant kingdom, and they play important roles in many biological processes that are closely related to plant growth and development. Recently, nsLTPs have been shown to respond to different forms of abiotic stresses. Despite the vital roles of nsLTPs in many plants, little is known about the nsLTPs in wheat. In this study, 330 nsLTP proteins were identified in wheat and they clustered into five types(1, 2, c, d, and g) by phylogenetic analysis with the nsLTPs from maize, Arabidopsis, and rice. The wheat nsLTPs of type d included three subtypes(d1, d2, and d3) and type g included seven subtypes(g1–g7). Genetic structure and motif pattern analyses showed that members of each type had similar structural composition. Moreover, GPI-anchors were found to exist in non-g type members from wheat for the first time. Chromosome mapping revealed that all five types were unevenly and unequally distributed on 21 chromosomes. Furthermore, gene duplication events contributed to the proliferation of the nsLTP genes. Large-scale data mining of RNA-seq data covering multiple growth stages and numerous stress treatments showed that the transcript levels of some of the nsLTP genes could be strongly induced by abiotic stresses, including drought and salinity, indicating their potential roles in mediating the responses of the wheat plants to these abiotic stress conditions. These findings provide comprehensive insights into the nsLTP family members in wheat, and offer candidate nsLTP genes for further studies on their roles in stress resistance and potential for improving wheat breeding programs.
基金supported by the Zhejiang Provincial S&T Project on Breeding of Agricultural (Food) Crops (2016C020502)the Major Science and Technology Innovation Program of Hangzhou, China (2015012A09)
文摘Stigma exsertion in male sterile lines of hybrid rice is important for seed yield.In the present study, ZS616 [Oryza sativa subsp.Xian(indica)], a male sterile line with a stigma exsertion rate(SER) as high as 94.5%, was crossed to DS552, a japonica line with almost no exserted stigmas.F3 plants with extremely low and high SER were sequenced to identify SER-associated quantitative trait loci(QTL).A major QTL for SER, qSER-3.1, was identified along with other QTL on chromosome 3 in a 3.9 Mb region.A total of 307 nonsynonymous single-nucleotide polymorphisms(SNPs) and 27 frame-shift insertion/deletions(InDels)differentiating ZS616 and DS552 were identified in the region containing qSER-3.1.Most SNPs(294) and InDels(25) were excluded after further analysis because they were shared by ZS616 and low(<2.0%) SER accessions in the Huazhong Agricultural University(HAU) core rice collection.Association analysis using the full HAU collection identified a 17-bp InDel in OS03 G0689400 as the most likely causal genetic variant underlying qSER-3.1.ZS616-type accessions(n = 54, with the 17-bp insertion) in the HAU collection had minimum(16.5%)and mean(39.6%) SERs significantly greater than those(n = 424) without the insertion(with minimum and mean SERs of 0.2% and 20.6%, respectively).Thus, this study identified a major QTL for stigma exsertion and revealed the mutation in a candidate gene for the QTL.
基金supported by grants from the National Key Research and Development Program of China(2016 YFD0300108)the National Natural Science Foundation of China(31671630)the earmarked fund for China Agriculture Research System(CARS-01-04A)。
文摘Environmental conditions greatly affect the growth of rice. To investigate the geographic differences in yield formation of single-season high-yielding hybrid rice in southern China, experiments were conducted in 2017 and 2018 in the upper and middle–lower reaches of the Yangtze River with 10–30 main locally planted high-yielding hybrid cultivars used as materials. Compared with rice planted in the middle–lower reaches of the Yangtze River, rice planted in the upper reaches has a longer tillering duration, higher accumulated temperature(≥10℃) during tillering period, but lower accumulated temperature and solar radiation from initial booting to maturity. Yield traits comparison between the upper and the middle–lower reaches of Yangtze River showed that the former had 48.1% more panicles per unit area while the latter had 46.4% more grains per panicle;the rice yield in the former was positively correlated with the seed setting rate and the dry matter accumulation before heading, while the latter was positively correlated with grains per panicle and dry matter accumulation from booting to maturity. Comparison of the same variety Tianyouhuazhan planted in different regions showed there was a significant positive correlation between panicle number and the duration of and accumulated temperature during the tillering period(r=0.982^(**), r=0.993^(**), respectively), and between grains per panicle and accumulated solar radiation during booting period(r=0.952~*). In the upper reaches of the Yangtze River, more than 90% of cultivars with an yield of greater than 11 t ha^(–1) had an effective panicle number of 250–340 m^(–2), and there was a significant negative correlation between seed setting rate and grains per panicle;therefore, the high-yielding rice production in these regions with a long effective tillering period(>40 d) should choose varieties with moderate grains per panicle, adopt crop managements such as good fertilizer and water measures during vegetative growth period to ensure a certain number of effective panicles, and to increase the dry matter accumulation before heading. While in regions with a short effective tillering period(<20 d) but good sunshine conditions during the reproductive growth period, such as the middle–lower reaches of the Yangtze River, high-yielding rice production should choose cultivars with large panicles, adopt good water and fertilizer managements during the reproductive growth period to ensure the formation of large panicles and the increase of dry matter accumulation after heading.
基金funded by the National Key Research and Development Program of China(2017YFD0301400)the Fundamental Research Funds for the Central Universities,China(266620202KPY014)。
文摘The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly investigated.This study uses a survey in 2016 and a field experiment in 2017 in Qianjiang,Hubei Province,China to assess the relative economics of concurrent rice-wheat(RW),rice-crayfish(RC),and crayfish monoculture(CM)models in waterlogged land areas.Thefield survey indicated that the RC model had a higher benefit-cost ratio(3.5:1)than the RW(2.0:1)and CM(3.1:1)models and the RC model protected farmers’enthusiasm for grain production facing unfavourable weather conditions.The field experiment aimed to explore nitrogen management strategies in RC fields.In the experiment,four levels of nitrogen concentration gradient-0 kg N ha^(-1)(0 N),75 kg N ha^(-1)(75 N),150 kg N ha^(-1)(150 N)and 225 kg N ha^(-1)(225 N),were set in a 2-year-old rice-crayfish(RC2)field,an 8-year-old rice-crayfish(RC8)field,and a RWfield as a control.Thefield experiment results suggested that the peak rice yield in RW,RC2,and RC8 occurred when 225 N,150 N and 75 N were used,respectively.In RC2 and RC8,however,residual feed-nitrogen that was not used by crayfish was utilized by rice plants.Thus,an optimal amount of nitrogen in RCfields was proposed to improve the nitrogen use efficiency and reduce environmental pollution by nitrogen fertilizer.Farmers use less nitrogen but have higher net income in RC than in RW and CM.It is necessary to sustainably develop integrated farming technologies(i.e.,properfield configurations for ricefields)to effectively sustain rice production.The results also showed that the RC farming model was a viable diversification option for rice farmers in waterlogged land.
基金supported by the National Natural Science Foundation of China(32071948)the Fundamental Research Funds for the Central Universities,China(2662020ZKPY015)the Guangxi Natural Science Foundation,China(2022GXNSFAA035488)。
文摘The rice cultivars carrying dep1(dense and erect panicle 1)have the potential to achieve both high grain yield and high nitrogen use efficiency(NUE).However,few studies have focused on the agronomic and physiological performance of those cultivars associated with high yield and high NUE under field conditions.Therefore,we evaluated the yield performance and NUE of two near-isogenic lines(NILs)carrying DEP1(NIL-DEP1)and dep1-1(NIL-dep1)genes under the Nanjing 6 background at 0 and 120 kg N ha^(–1).Grain yield and NUE for grain production(NUEg)were 25.5 and 21.9%higher in NIL-dep1 compared to NIL-DEP1 averaged across N treatments and planting years,respectively.The yield advantage of NIL-dep1 over NIL-DEP1 was mainly due to larger sink size(i.e.,higher total spikelet number),grainfilling percentage,total dry matter production,and harvest index.N utilization rather than N uptake contributed to the high yield of NIL-dep1.Significantly higher NUEg in NIL-dep1 was associated with higher N and dry matter translocation efficiency,lower leaf and stem N concentration at maturity,and higher glutamine synthetase(GS)activity in leaves.In conclusion,dep1 improved grain yield and NUE by increasing N and dry matter transport due to higher leaf GS activity under field conditions during the grain-filling period.
基金This research was financially supported by the National Key R&D Program of China(2016YFD0100502)the National Natural Science Foundation of China(31771773)。
文摘Haynaldia villosa(2n=14,VV),a wild grass of the subtribe Triticeae,serves as potential gene resources for wheat genetic improvement.In this study,the proteome characterization during grain development of Yangmai 5 and Yangmai 5-H.villosa 6VS/6AL translocation line was investigated by a comparative proteomic approach.Two-dimensional electrophoresis identified 81 differentially accumulated proteins(DAPs)during five grain developmental stages in wheat-H.villosa translocation line.These proteins were mainly involved in stress defense,storage protein,energy metabolism,protein metabolism and folding,carbon metabolism,nitrogen metabolism,and starch metabolism.In particular,6VS/6AL translocation led to significant upregulation of 36 DAPs and specific expression of 11 DAPs such as chitinase,thaumatin-like proteins,glutathione transferase,α-amylase inhibitor,heat shock proteins,and betaine aldehyde dehydrogenase.These proteins mainly involved in biotic and abiotic stress responses.Further analysis found that the upstream 1500 promoter regions of these stress-responsive DAP genes contained multiple high-frequency cis-acting elements related to stress defense such as abscisic acid response element ABRE,methyl jasmonate(MeJA)-response element TGACG-motif and CGTCA-motif involved in oxidative stress and antioxidant response element(ARE).RNA-seq and RT-qPCR analyses revealed the high expression of these stress-defensive DAP genes in the developing grains,particularly at the early-middle grain filling stages.Our results demonstrated that 6VS chromosome of H.villosa contains abundant stress-defensive proteins that have potential values for wheat genetic improvement.
基金Supported by National Key R&D Program(2016YFD030010)National Innovation Experiment Program for University students(20150083,2016099)
文摘In order to investigate effects of topdressing on grain yield and N use efficiency of mechanically-transplanted hybrid rice, this experiment was conducted with 2-line hybrid rice cultivars, Quanliangyou 1 and Quanliangyou 681 with 3 application levels of N fertilizer, N_0, N_1, N_2, respectively. The results showed that there were no significant differences in grain yields of the 2 varieties between treatments N_1 and N_2. It was indicated that N is not the factor which could limit grain yield within limited application levels of N fertilizer. High N fertilizer treatment could contribute to the formation of effective panicles and spikelets per panicle, but it could also lead to the decline in grain filling rate. It was suggested that lowering the amount of Nfertilizer could facilitate improvement of N-use efficiency.
文摘Land,the foundation of agriculture and farmers,is the most basic capital goods of agricultural production. Confirmation of land right in rural areas not only effectively protects the land contract management right of peasants and helps to realize the informatization management of land contract,but also lays a foundation for land circulation and scale management. In addition,it also promotes the realization of agricultural modernization. This paper analyzes the problems in the confirmation of land right and sets forth recommendations under the premise of realizing the importance of confirmation of land right.
基金Supported by Project of Hubei Agricultural Science and Technology Innovation Center(2007-620-003-03-05)Open Fund Project of Hubei Collaborative Innovation Center for Grain Industry(LXT-16-03)
文摘In the economic new normal,production of hybrid rice seed in foreign countries is the necessity for reducing farmland area occupied by seed production,for ensuring national grain security,realizing cost reducing and quality improving of hybrid rice seed,strengthening competitive power at international market,guiding seed industry of China to go out,building transnational seed groups with core competitive power,establishing close relationship with developing countries,promoting the construction of One Belt One Road strategy,serving overall situation of diplomacy,and setting up excellent international image. It is feasible to produce hybrid seed in foreign countries considering( i) high overall national strength of China,( ii) rapid and healthy growth of China's seed industry and increasingly mature hybrid rice seed production technologies,( iii) excellent climatic conditions of foreign host countries of seed production,and( iv) low land and labor price of foreign host countries of seed production. However,there are social and policy risks,technology and trade barrier risks,market,production,and other risks for production of hybrid rice seed in foreign countries. In view of these,it came up with recommendations,including allowing delivering parent seeds of hybrid rice to foreign countries,allowing delivering hybrid rice seed to China,solving the problem of " opening in protection,and protection in opening",and formulating a package of support policies.
基金financially supported by the National Key Research and Development Program of China(2020YFE0202300)the Agricultural Science and Technology Innovation Program(CAASZDRW202109 and CAAS-ZDRW202002)。
文摘Cytokinins(CKs)function in plant development and during stress responses,but their role in drought tolerance in wheat is unknown.In the present study,24 isopentenyltransferase(IPT)genes,encoding ratelimiting enzymes in CK biosynthesis were identified in the wheat genome.The chromosomal locations and structures of the genes,protein properties,and phylogenetic relationships were characterized.ATP/ADP TaIPT genes showed tissue-specific expression.TaIPT2,TaIPT7,and TaIPT8 expression was rapidly induced by 0.5–1 h drought treatments,which decreased to low levels after 2 h drought treatment,as did most other TaIPT genes.TaIPT8-5a/5b/5d triple mutants showed decreased levels of tZtype CK under normal and drought conditions and reduced drought tolerance,which,however,did not manifest as phenotype alterations.By contrast,transgenic wheat plants with drought-induced TaIPT8showed increased drought tolerance.Our study provides a foundation for further investigation of TaIPT genes and novel insights into the role of CKs in the drought response of wheat.
基金partially supported by the National Natural Science Foundation of China(31701391)the National Key Laboratory of Crop Genetic Improvement Self-Research Program(ZW18B0101)。
文摘Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F_(2) population derived from two landraces: Chuan 7(C7) and Haoboka(HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F_(2) population of 940 plants to construct low-and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F_(2) population or BC_(4)F_(2) populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1(sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture.
基金supported by the National Natural Science Foundation of China(Grant No.31371571)the National High Technology Research and Development Program of China(863 Program)(Grant No.2014AA10A605)the Fundamental Research Funds for the Central Universities(Grant No.2662017JC001)
文摘Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.
基金funded by the National Key Research and Development Program of China (2016YFD0100301)Project for Cultivating New Transgenic Varieties (2016ZX08009003-004)+2 种基金the Agricultural Science and Technology Innovation Program and the Cooperation and Innovation Mission (CAAS-ZDXT202001)Open Fund of Hubei Collaborative Innovation Center for Grain Industry (HCICGI2020-06)the National Natural Science Foundation of China (U19A2025 and 31870229)。
文摘Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present study, large phenotypic variation was observed in 760 accessions from the 3 K Rice Genomes Project for both appearance quality and cooked rice elongation. Most component traits of appearance quality and cooked rice elongation showed significant pairwise correlations, but a low correlation was found between appearance quality and cooked rice elongation. A genome-wide association study identified 74 QTL distributed on all 12 chromosomes for grain length, grain width, length to width ratio, degree of endosperm with chalkiness, rice elongation difference, and elongation index. Thirteen regions containing QTL stably expressed in multiple environments and/or exerting pleiotropic effects on multiple traits were detected. By gene-based association analysis and haplotype analysis, 46 candidate genes, including five cloned genes, and 49 favorable alleles were identified for these 13 QTL. The effect of the candidate gene Wx on rice elongation difference was validated by a transgenic strategy. These results shed light on the genetic bases of appearance quality and cooked rice elongation and provide gene resources for improving rice quality by molecular breeding.
基金Supported by the National Key Research and Development Program of China(2016YFD0300107,2017YFD0300202-3)National Natural Science Foundation of China(31371580,31871578)
文摘Waterlogging is one of the most factors limiting wheat production in the middle and lower reaches of the Yangtze River Plain of China,especially in the middle and late stages of wheat.Wheat varieties‘Jingmai102’(JM102)and‘Yangmai158’(YM158)were planted to study the dynamic changes of photosynthetic characteristics in flag leaf and the influence of waterlogging at anthesis on the yield and components and dry matter accumulation and remobilization of winter wheat in above ground.The results showed that the SPAD values slightly increased at 1 day after anthesis(d),and then kept decreasing with the increase of waterlogging time.The decrease in SPAD value was more remarkably in YM158 than that in JM102.As for the chlorophyll fluorescence parameters,the photochemical efficiency(Fv/Fm),potential activity(Fv/Fo)of photosystem II,and electronic transmission(Fm/Fo)on photosystem II increased first and then decreased with the increase of waterlogging days after anthesis.The quantum ratio of heat dissipation(Fo/Fm)had a tendency opposite to that of Fv/Fm,and the change range of JM102 was lower than that of YM158.For the grain yield and components,waterlogging at anthesis decreased the dry weight of single stem,grain yield,1 000-kernel weight,spikelet per panicle,and harvest index,and the reduction of JM102 was smaller than that of YM158.As for the accumulation and remobilization of dry matter,the accumulation of dry matter after anthesis decreased significantly under waterlogging condition(WL),and the reduction of JM102 was smaller than that of YM158.In conclusion,waterlogging at anthesis significantly affected the photosynthetic characteristics,yield and components in both varieties,but different varieties exhibited different tolerances to waterlogging stress and YM158 was more sensitive to water stress than JM102.