增强UV-B辐射与不同水平氮素对谷子(Setaria italica(L．)Beauv．)叶片保护物质及保护酶的影响

研究了生长在1.875 mmol.L-1和15 mmol.L-1硝态氮素水平条件下的谷子(Setaria italica(L.)Beauv.)开花期间在进行强度为7.12 kJ.m-.2d-1增强UV-B辐射处理时叶片类黄酮含量、苯丙氨酸解氨酶(PAL)和保护酶活性变化差异。主要结果表明在开花期无论是否进行增强UV-B辐射处理,较低水平氮素均比较高水平氮素更有利于提高谷子叶片PAL活性;叶片类黄酮含量除在进行增强UV-B处理时较低氮素条件下生长的谷子在开花末期显著高于较高氮素条件下生长的谷子外,受氮素水平影响不甚明显。而在开花期不进行与进行增强UV-B辐射处理,氮素水平对叶片保护酶的影响有所差异:不进行增强UV-B辐射处理,整个开花期氮素水平对谷子叶片SOD活性有显著影响而对ASP活性无显著影响,对CAT和POD活性则在开花期部分阶段有显著影响。进行增强UV-B辐射处理,整个开花期氮素水平对谷子叶片SOD与CAT活性有显著影响而对ASP、POD活性影响不显著。

古粟(Setaria italica Beauv.)研究综述

粟于中国北方俗称"谷子",脱壳后称"小米",南方则通称"小米",在古代粮食作物中的地位举足轻重。近世学者对粟的史前考古发现、起源与传播、稷的粟黍之争、生产与文化等方面行了研究,并且已经取得了很多成果,但在某些方面的探索还非常不够,如史前人类生活中粟作的地位与演变;古粟的栽培、储藏、加工与利用技术;历史上粟的生产布局、价格与产量的变动;粟与古代经济、政治、文化的关系等。今后应加强在这些方面的投入,不断拓展粟研究的深度和广度。

The NAC-like transcription factor Si NAC110 in foxtail millet(Setaria italica L.) confers tolerance to drought and high salt stress through an ABA independent signaling pathway

Foxtail millet（Setaria italica（L.）P.Beauv）is a naturally stress tolerant crop.Compared to other gramineous crops,it has relatively stronger drought and lower nutrition stress tolerance traits.To date,the scope of functional genomics research in foxtail millet（S.italic L.）has been quite limited.NAC（NAM,ATAF1/2 and CUC2）-like transcription factors are known to be involved in various biological processes,including abiotic stress responses.In our previous foxtail millet（S.italic L.）RNA seq analysis,we found that the expression of a NAC-like transcription factor,SiNAC110,could be induced by drought stress;additionally,other references have reported that SiNAC110 expression could be induced by abiotic stress.So,we here selected SiNAC110 for further characterization and functional analysis.First,the predicted SiNAC110 protein encoded indicated SiNAC110 has a conserved NAM（no apical meristem）domain between the 11–139 amino acid positions.Phylogenetic analysis then indicated that SiNAC110 belongs to subfamily III of the NAC gene family.Subcellular localization analysis revealed that the SiNAC110-GFP fusion protein was localized to the nucleus in Arabidopsis protoplasts.Gene expression profiling analysis indicated that expression of SiNAC110 was induced by dehydration,high salinity and other abiotic stresses.Gene functional analysis using SiNAC110 overexpressed Arabidopsis plants indicated that,under drought and high salt stress conditions,the seed germination rate,root length,root surface area,fresh weight,and dry weight of the SiNAC110 overexpressed lines were significantly higher than the wild type（WT）,suggesting that the SiNAC110 overexpressed lines had enhanced tolerance to drought and high salt stresses.However,overexpression of SiN AC110 did not affect the sensitivity of SiNAC110 overexpressed lines to abscisic acid（ABA）treatment.Expression analysis of genes involved in proline synthesis,Na＋/K＋transport,drought responses,and aqueous transport proteins were higher in the SiNAC110overexpressed lines than in the WT,whereas expression of ABA-dependent pathway genes did not change.These results indicated that overexpression of SiNAC110 conferred tolerance to drought and high salt stresses,likely through influencing the regulation of proline biosynthesis,ion homeostasis and osmotic balance.Therefore,SiNAC110 appears to function in the ABA-independent abiotic stress response pathway in plants.

The application of Fourier transform mid-infrared(FTIR) spectroscopy to identify variation in cell wall composition of Setaria italica ecotypes

Cell wall composition in monocotyledonous grasses has been identified as a key area of research for developing better feedstocks for forage and biofuel production.Setaria viridis and its close domesticated relative Setaria italica have been chosen as suitable monocotyledonous models for plants possessing the C4 pathway of photosynthesis including sorghum,maize,sugarcane,switchgrass and Miscanthus×giganteus.Accurate partial least squares regression（PLSR）models to predict S.italica stem composition have been generated,based upon Fourier transform mid-infrared（FTIR）spectra and calibrated with wet chemistry determinations of ground S.italica stem material measured using a modified version of the US National Renewable Energy Laboratory（NREL）acid hydrolysis protocol.The models facilitated a high-throughput screening analysis for glucan,xylan,Klason lignin and acid soluble lignin（ASL）in a collection of 183 natural S.italica variants and clustered them into classes,some possessing unique chemotypes.The predictive models provide a highly efficient screening tool for large scale breeding programs aimed at identifying lines or mutants possessing unique cell wall chemotypes.Genes encoding key catalytic enzymes of the lignin biosynthesis pathway exhibit a high level of conservation with matching expression profiles,measured by RT-q PCR,among accessions of S.italica,which closely mirror profiles observed in the different developmental regions of an elongating internode of S.viridis by RNASeq.

Identification of no pollen 1 provides a candidate gene for heterosis utilization in foxtail millet(Setaria italica L.)

Male sterility is a common biological phenomenon in plant kingdom and has been used to generate male-sterile lines, which are important genetic resources for commercial hybrid seed production. Although increasing numbers of male-sterility genes have been identified in rice(Oryza sativa) and Arabidopsis(Arabidopsis thaliana), few male-sterility-related genes have been characterized in foxtail millet(Setaria italica). In this study, we isolated a male-sterile ethyl methanesulfonate-generated mutant in foxtail millet, no pollen 1(sinp1), which displayed abnormal Ubisch bodies, defective pollen exine and complete male sterility. Using bulk segregation analysis, we cloned SiNP1 and confirmed its function with CRISPR/Cas9 genome editing. SiNP1 encoded a putative glucose-methanol-choline oxidoreductase.Subcellular localization showed that the SiNP1 protein was preferentially localized to the endoplasmic reticulum and was predominantly expressed in panicle. Transcriptome analysis revealed that many genes were differentially expressed in the sinp1 mutant, some of which encoded proteins putatively involved in carbohydrate metabolism, fatty acid biosynthesis, and lipid transport and metabolism, which were closely associated with pollen wall development. Metabolome analysis revealed the disturbance of flavonoids metabolism and fatty acid biosynthesis in the mutant. In conclusion, identification of SiNP1 provides a candidate male-sterility gene for heterosis utilization in foxtail millet and gives further insight into the mechanism of pollen reproduction in plants.

Effects of Fertility and Density on Biomass Production,Translocation and Lodging Resistance of Millet(Setaria italica L.)in North China

In this study, the plant biomass production, biomass translocation rates across tissues and the lodging resistant-associated traits of millet （ Setaria italica L.） in North China were investigated. Among the four summer millet cultivars, Baogu 19 exhibited improved plant biomass （PB） production at flowering and maturity stages, biomass translocation amount （BTA） from vegetative tissues to seeds during filling period, and lodging resistant-associated （LRA） traits compared with other cultivars, including enhanced stem lignin contents, increased anti-broken resistance （ABR）, anti-puncturing resistance （APR）, and stem diameter （SD） of plants. Compared with treatment regular cultivation （RC）, high fertility treatment （HF） increased the plant BP, BTA from vegetative tissue to seed at filling stage, and the plant LRA traits; whereas high density treatment （HD） decreased the plant BP at plant level, plant BTA from vegetative tissues to seeds at filling stage, and the plant LRA traits. Correlation analysis revealed that stem ABR is significantly correlated with the plant lodging resistant-associated traits including APR and SD in the summer millet cultivars examined under various cultivation treatments. Our investigation indicates that cultivar Baogu 19 together with suitable fertilization and density can promote the plant biomass production, enhance vegetative tissue biomass translocation to seeds, and improve the lodging resistance of summer millet plants in North China.

Calcineurin B-like protein 5(SiCBL5)in Setaria italica enhances salt tolerance by regulating Na^(+)homeostasis

Salinity,a major abiotic stress,reduces plant growth and severely limits agricultural productivity.Plants regulate salt uptake via calcineurin B-like proteins(CBLs).Although extensive studies of the functions of CBLs in response to salt stress have been conducted in Arabidopsis,their functions in Setaria italica are still poorly understood.The foxtail millet genome encodes seven CBLs,of which only SiCBL4 was shown to be involved in salt response.Overexpression of SiCBL5 in Arabidopsis thaliana sos3-1 mutant rescued its salt hypersensitivity phenotype,but that of other SiCBLs(SiCBL1,SiCBL2,SiCBL3,SiCBL6,and SiCBL7)did not rescue the salt hypersensitivity of the Atsos3-1 mutant.SiCBL5 harbors an N-myristoylation motif and is located in the plasma membrane.Overexpression of SiCBL5 in foxtail millet increased its salt tolerance,but its knockdown increased salt hypersensitivity.Yeast two-hybrid and firefly luciferase complementation imaging assays showed that SiCBL5 physically interacted with SiCIPK24 in vitro and in vivo.Cooverexpression of SiCBL5,SiCIPK24,and SiSOS1 in yeast conferred a high-salt-tolerance phenotype.Compared to wild-type plants under salt stress conditions,SiCBL5 overexpressors showed lower accumulations of Na^(+) and stronger Na^(+) efflux,whereas RNAi-SiCBL5 plants showed higher accumulations of Na^(+) and weaker Na^(+) efflux.These results indicate that SiCBL5 confers salt tolerance in foxtail millet by modulating Na^(+) homeostasis.

Genetic Diversity and Classification of Chinese Elite Foxtail Millet [Setaria italica (L.) P. Beauv.] Revealed by Acid-PAGE Prolamin

Arid and semi-arid regions of China account for more than half of the country. Because of drought resistance and high nutritive value, elite foxtail millet (Setaria Italica (L.) P. Beauv.) is one of the most important cereal crops in China. Evaluation of germplasm and genetic diversity of foxtail millet is still in its infancy, but prolamin could play an important role as a protein marker. To investigate the genetic diversity and population structure of foxtail millet from different ecological zones of China, 90 accessions of foxtail millet were collected from three major ecological areas: North, Northwest, and Northeast China. The prolamin contents were examined by acid polyacrylamide gel electrophoresis (acid-PAGE). Five to twenty-two prolamin bands appeared in tested varieties, of which were polymorphic, so prolamin patterns of foxtail millet varieties can be used in variety identification and evaluation. Structure analysis identified six groups, which matches their pedigree information but not their geographic origins. This indicated a high degree (87.78%) of consistency with a phylogenetic classification based on SSR. The results showed prolamin banding patterns were an effective method for analyzing foxtail millet genetic variability.

The protoplasts isolation,culture and shoots regeneration of broccoli(Brassica oleracea var.italica)

Eight F1-hybrid cultivars of broccoli were studied.We obtained cell division,celled colonies and p-calli in 5 cultivars,roots and shoots regeneration in one cultivar.The leavesof propagated plantlets in vitro were cut into 1—2mm pieces,isolated with an enzyme solutioncontaining 2% cellulase and 1%macerase on a rotary shaker（50 rpm,21℃,3h,2500 lux light）,and purified with a 0.5M sucrose solution.The purified protoplasts were placed on a drop of 1%agarose.2—3 ml liquid medium was added around the agarose drops,and all of the cultures wereincubated at 25℃ under light（4000 lux）for 16 hours.3—5 days after isolation the cell divisionwas found.About 7 days after incubation 4 multicellular colonies were formed.After 3—5 wksome p-calli were developed.When the p-calli were 2—3 mm in diameter it was transferred to asolidified medium.Once they were developed to 1 cm in diameter they were transferred on a re-generation medium.About 5 months after incubation some roots and shoots grown from the calliwere

Total flavonoids from Anchusa italica improves cardiac function and attenuates cardiac remodeling post-myocardial infarction in mice

OBJECTIVE The plant of Anchusa italicahas been traditionally used in Uighur medicine for the treatment of cardiovascular and cerebrovascular diseases in China.Our previous study showed that total flavonoids from Anchusa italica(TFAI)exhibited potent cardioprotection on acute ischemia/reperfusion injured rats.This study was undertaken to investigate the effects of TFAI on chronic myocardial infarction in mice and the underlying mechanism.METHODS Total flavonoids were extracted from the whole herb of Anchusa italica and were characterized using HPLC-MS analysis.The left anterior descending branch of coronary artery was ligated to induce myocardial infarction in mice.After surgery,the mice were orally fed with TFAI at the doses of 10,30 and 50 mg·kg-1 body mass per day for a total of four weeks.Cardiac function and infarct size were measured,and the levels of inflammatory mediators were detected.Hematoxylin and eosin(HE)stain and Masson Trichrome stain were performed.The apoptotic factors such as Bax,Bcl-2 and cleaved caspase 3 as well as the key proteins in the PI3K/Akt/mTOR signaling pathway were examined by Western blotting.RESULTS The content of total flavonoids in TFAI was 56.2%.Four weeks following the MI surgery,TFAI enhanced the survival rate in post-MI mice.TFAI administration at the doses of 30 and 50 mg·kg-1 significantly reduced the infarct size and improved cardiac function indicated by elevated EF and FS.Assay of inflammation factors showed that the sera levels of TNF-α,IL-1β and IL-6 were significantly decreased by TFAI treatment as compared to the MI group.HE stain and Masson Trichrome stain demonstrated that TFAI suppressed myocyte hypertrophy and cardiac fibrosis indicated by decreased cross-section area and collagen volume.Western blot analysis showed that cleaved caspase 3 and Bax/Bcl-2 were signifi⁃cantly downregulated following TFAI treatment.Additionally,TFAI treatment significantly suppressed the activation of the PI3K/Akt/mTOR signaling pathway.CONCLUSION TFAI exerts a protective effect against chronic myocardial infarction and its beneficial effects on cardiac function and cardiac remodeling might be at least attributable to anti-inflammation and suppression of the PI3K/Akt/mTOR signaling pathway.

Review of Research Situation of Brassica oleracea var.italica

Broccoli(Brassica oleracea var.italica),also called green broccoli,green cauliflower,and calabrese,belongs to genus Brassica in family Cruciferae,and is annual or biennial herbaceous plant.Both broccoli and cauliflower are varieties of Brassica oleracea L.Broccoli is rich in nutrients.Its protein,amino acids and vitamins are higher than cauliflower,and broccoli is easy to grow,the supply period is long,and it has a good market and economic value.This paper introduced broccoli-related information from broccoli's nutritional value,cultivation techniques,existing problems and prospects.In addition,on the basis of existing studies,it discussed the future development prospects of broccoli,in order to promote the production research of broccoli in China.

The m^(6)A reader SiYTH1 enhances drought tolerance by affecting the messenger RNA stability of genes related to stomatal closure and reactive oxygen species scavenging in Setaria italica

Foxtail millet(Setaria italica),a vital drought-resistant crop,plays a significant role in ensuring food and nutritional security.However,its drought resistance mechanism is not fully understood.N6-methyladenosine(m^(6)A)modification of RNA,a prevalent epi-transcriptomic modification in eukaryotes,provides a binding site for m^(6)A readers and affects plant growth and stress responses by regulating RNA metabolism.In this study,we unveiled that the YT521-B homology(YTH)family gene SiYTH1 positively regulated the drought tolerance of foxtail millet.Notably,the siyth1 mutant exhibited reduced stomatal closure and augmented accumulation of excessive H_(2)O_(2)under drought stress.Further investigations demonstrated that SiYTH1 positively regulated the transcripts harboring m^(6)A modification related to stomatal closure and reactive oxygen species(ROS)scavenging under drought stress.SiYTH1 was uniformly distributed in the cytoplasm of SiYTH1-GFP transgenic foxtail millet.It formed dynamic liquid-like SiYTH1 cytosol condensates in response to drought stress.Moreover,the cytoplasmic protein SiYTH1 was identified as a distinct m^(6)A reader,facilitating the stabilization of its directly bound SiARDP and ROS scavenging-related transcripts under drought stress.Furthermore,natural variation analysis revealed SiYTH1AGTG as the dominant allele responsible for drought tolerance in foxtail millet.Collectively,this study provides novel insights into the intricate mechanism of m^(6)A reader-mediated drought tolerance and presents a valuable genetic resource for improving drought tolerance in foxtail millet breeding.

西兰花(Brassica oleracea var.italica)硫代葡萄糖苷酶基因cDNA分子克隆及其特征分析

目的:研究西兰花硫代葡萄糖苷酶(简称硫苷酶)cDNA的结构特征,为硫苷酶异源表达打下基础。方法:以西兰花幼苗为试材,根据同源序列法PCR扩增硫苷酶特异cDNA片段,再用3′RACE和5′RACE分别扩增cDNA3′端序列和5′端序列,经序列拼接获得西兰花硫苷酶全长cDNA序列。利用在线蛋白质分析系统对其编码的氨基酸序列进行结构特征分析,在NCBICDD数据库中查找保守结构域,在SWISS-MODEL上进行在线蛋白同源模建,用MEGA3.1构建NJ系统树。结果:该基因cDNA全长1830bp,含有一个1641bp的ORF及31bp的5′端非翻译区和158bp的3′端非翻译区,命名为BoMyr2(GenBank登录号为EU004075);编码氨基酸序列含有20个氨基酸长度的信号肽及9个天冬酰胺N末端糖基化位点,编码的蛋白分子质量(Mw)约为62.2kD,等电点(pI)为8.71;BoMyr2推测氨基酸序列含有糖基水解酶家族1特有的糖基水解酶结构域,其编码蛋白与PDB库中白芥硫苷酶有类似的三维结构,具有明显的β/α(TIM)桶结构;BoMyr2应归为硫苷酶基因家族的MB亚族。

微藻生物肥提高谷子对氮磷胁迫的耐受性

【目的】氮磷营养缺乏是作物生长发育的重要限制因素。微藻生物肥是由单细胞光合藻类生物质构成的一种新型肥料,其促进作物生长和改良土壤肥力的功效备受关注。本研究旨在解析微藻生物肥对谷子(Setaria italica L.)生长的促进作用,特别是提高谷子对氮磷缺乏的耐受性的生物学功能,为微藻生物肥在谷子等作物的化肥减量和绿色可持续生产的应用提供理论支撑。【方法】供试谷子品种为‘晋谷21’。采用水培试验,设置正常氮磷(霍格兰标准营养液中氮和磷含量分别为210和71 mg/L)、无氮磷(营养液中氮和磷含量均为0 mg/L)和1/2氮磷(营养液中氮和磷含量分别为105和35.5 mg/L)3个氮磷水平。制备小球藻(Chlorella sp.DT01)(DT)、埃氏小球藻(Chlorella emersonii)(AS)和蛋白核小球藻(Chlorella pyrenoidosa)(DB)3种微藻生物肥,分别与3个氮磷处理液等比混合,共构成9个处理,每个氮磷水平下设置1个不添加微藻微生物溶液处理为对照。在谷子幼苗生长至两叶一心时,将其移入处理液中,在温室条件下连续培养9天,期间每3天补充1次处理液。处理结束时,测定各处理谷子幼苗的生长指标、生物量、色素含量、光合活性和氮磷含量等生理生化参数,并通过qRT-PCR技术分析氮磷转运蛋白相关基因(SiNRT1.11、SiNRT2.1、SiPHT1.2和SiPHT1.1)的表达谱。【结果】与正常氮磷处理相比,无氮磷和1/2氮磷处理均显著降低了谷子幼苗生物量、光合色素(叶绿素a,b和类葫萝卜素)含量和光合作用。在3种剂量氮磷处理下,施用3种微藻生物肥处理均显著提高谷子幼苗鲜重和干重、光合色素含量(特别是类胡萝卜素)和光合作用参数[实际光化学效率Y(II),光化学淬灭系数qP和非光化学淬灭系数NPQ]。此外,微藻生物肥还显著增加了谷子幼苗全氮和全磷含量。微藻生物肥DT处理的促生效应最显著。qRT-PCR检测谷子幼苗氮磷转运相关基因表达显示,微藻生物肥DT处理显著上调谷子幼苗地上部硝酸盐转运蛋白基因SiNRT1.11和根系硝酸盐转运蛋白基因SiNRT2.1的表达,以及根系中磷酸盐转运蛋白基因SiPHT1.2和SiPHT1.1的表达。【结论】施用微藻生物肥能显著提高谷子幼苗地上部硝酸盐转运蛋白基因SiNRT1.11和根系硝酸盐转运蛋白基因SiNRT2.1,以及根系中磷酸盐转运蛋白基因SiPHT1.2和SiPHT1.1的表达,进而改善谷子幼苗生长和光合生理特性,提高谷子对氮磷胁迫的抗性。

BoMyrosinase plays an essential role in sulforaphane accumulation in response to selenite treatment in broccoli

Sulforaphane, a naturally specialized metabolite, plays significant roles in human disease prevention and plant defense. Myrosinase(MY) is a key gene responsible for the catalysis of sulforaphane formation, but the molecular mechanisms through which MY regulates sulforaphane biosynthesis in plants remains largely unknown. Here, we discovered that the change of sulforaphane content in broccoli sprouts caused by exogenous selenite treatments is positively related to BoMY expression. BoMY overexpression in the Arabidopsis thaliana tgg1 mutants could dramatically increase myrosinase activity and sulforaphane content in the rosette leaves of 35S::BoMY/tgg1 and rescue its phenotypes.Moreover, an obvious increase of myrosinase activity and sulforaphane content was displayed in transgenic BoMY-overexpressed broccoli lines.In addition, a 2 033 bp promoter fragment of BoMY was isolated. Yeast one-hybrid(Y1H) library screening experiment uncovered that one bHLH transcription factor, BoFAMA, could directly bind to BoMY promoter to activate its expression, which was further evidenced by Y1H assay and dual-luciferase reporter assay. BoFAMA is a selenite-responsive transcription factor that is highly expressed in broccoli leaves;its protein is solely localized to nucleus. Additionally, genetic evidence suggested that the knockdown of FAMA gene in Arabidopsis thaliana could significantly decrease sulforaphane yield by inhibiting the expression of myrosinase genes. Interestingly, exogenous selenite supply could partially restore the low level of sulforaphane content in transgenic Arabidopsis FAMA-silencing plants. Our findings uncover a novel function of FAMAMY module in the regulation of selenite-mediated sulforaphane synthesis and provide a new insights into the molecular mechanism by which selenite regulates the accumulation of sulforaphane in plants.

谷子萌发期耐盐种质鉴定及应用

本研究利用不同浓度NaCl溶液对10份谷子(Setaria italica L.)种质进行处理,通过分析其萌发期的相对发芽势、相对发芽率、相对芽长以及相对根长等4项指标,明确了适于谷子萌发期耐盐性鉴定的NaCl浓度为180 mmol/L。在该浓度下,利用主成分分析和聚类分析等方法,对180份种质资源进行了耐盐性综合评价和等级划分。结果显示,除相对发芽率和相对芽长之间相关性不显著以外,其余指标之间均呈极显著正相关;主成分分析结果表明,这4项指标可作为谷子耐盐性评价的重要指标;聚类分析结果将180份谷子种质分为极端耐盐、耐盐、盐敏感和极端盐敏感4类;进一步采用隶属函数进行综合评价,筛选到硷谷、衡谷12、齐头白、K-3606和晋谷20等5份极端耐盐种质材料。最后,在该浓度处理下,对黑枝谷×长农35号(极端盐敏感×耐盐)F7代重组近交系遗传群体进行了初步分析,发现40份株系耐盐性等级频率分布近似正态分布,表明该群体适宜耐盐QTL挖掘。研究结果说明,在180 mmol/L NaCl处理下,通过谷子萌发期相对发芽势、相对发芽率、相对芽长和相对根长等4个指标能较好地区分不同种质耐盐性的差异。

施氮量对谷子产量、氮素利用及小米品质的影响

【目的】明确不同施氮量下谷子产量、干物质分配和氮素累积转运特征,分析氮用量对小米糊化特性和有益微量元素含量的影响及其与植株氮素累积的关系,探究植株氮素营养对小米品质的影响。【方法】于2020—2021年在山西省沁县研究4个施氮水平(0、75、120和150 kg·hm^(-2))对春播谷子产量、氮素吸收与利用特征及小米品质的影响。【结果】施氮提高谷子收获穗数、穗粒数和植株的干物质生产能力,增加了氮素由营养器官向籽粒的转运率,促进了干物质及氮素向籽粒的分配,从而提高产量。施氮也提高了小米中铁、锌、钙、镁和硒的含量,其中,施氮75 kg·hm^(-2)时上述元素含量的增幅最大,氮利用率最高。与不施氮相比,施氮75 kg·hm^(-2)时谷子收获穗数、穗粒数、产量、地上部生物量、收获指数、氮素累积总量和氮素转运率增幅最高,增幅分别可达7.5%、23.3%、31.0%、21.2%、8.6%、40.3%和9.2%,小米中铁、锌、钙、镁和硒含量的增幅分别为37.2%、43.6%、56.0%、30.5%和16.9%。过量施氮(150 kg·hm^(-2))不利于谷子穗粒数和收获指数的提高及氮素由营养器官向籽粒的转运,与施氮量75 kg·hm^(-2)比较,两年氮素转运率分别降低了23.1%和28.2%;氮素施用过量也降低了小米支链淀粉含量,淀粉形成受限,抑制了小米粉最终黏度、回升值和峰谷黏度,影响糊化品质,同时氮肥利用率低至25%左右。谷子地上部氮吸收量与小米中铁、锌、钙、镁和硒含量呈极显著的正相关,但与小米中支链淀粉含量、小米粉的最终黏度和峰谷黏度呈显著的负相关。【结论】施氮量在75—120kg·hm^(-2),能促进谷子干物质及氮素向籽粒的分配,实现籽粒产量、小米糊化品质和有益微量元素含量的同步提升。

谷子苗期对不同干旱胁迫的生理响应

采用聚乙二醇(Polyethylene glycol,PEG)溶液模拟干旱环境,对谷子种质资源进行室内萌发期抗旱性鉴定评价,旨在筛选出具有抗旱特性的优质品种。以冀谷37和冀谷38抗逆谷子品种为试验材料,并以华北夏谷区域广适性品种豫谷18作为对照,采用不同浓度PEG对其进行干旱胁迫处理,并对处理7 d后幼叶的丙二醛、甜菜碱、游离脯氨酸、叶绿素含量以及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化物酶(Peroxidase,POD)活性进行检测。结果表明,与对照品种豫谷18相比,冀谷37和冀谷38在中度和重度干旱胁迫(12%PEG、18%PEG)下丙二醛含量显著降低;冀谷38在中度和重度干旱胁迫下渗透调节物质游离脯氨酸含量显著增加,冀谷37和冀谷38甜菜碱含量均显著增加;冀谷38 SOD活性显著增强,但冀谷37仅在轻度和重度干旱胁迫(6%PEG、18%PEG)SOD活性高于豫谷18;冀谷37和冀谷38的POD活性在重度干旱胁迫下显著降低;冀谷38叶绿素含量均显著增加,但冀谷37仅在轻度和中度胁迫(6%PEG、12%PEG)下叶绿素含量显著增加。综上,冀谷37和冀谷38在幼苗期具有较强的耐旱能力,耐旱性优于对照品种豫谷18,且冀谷38抗旱能力强于冀谷37。

谷子CPP基因家族鉴定及外源硒响应分析

【目的】探究谷子CPP基因家族成员特征及在外源硒处理下的响应模式,为谷子富硒高叶酸新品种选育提供遗传材料。【方法】借助生物信息学工具鉴定谷子CPP家族成员,用qRT-PCR技术对CPP基因在不同组织及外源硒处理下的表达水平进行检测。【结果】(1)谷子基因组中包含9个CPP基因,定位于6条染色体上,分别命名为SiCPP1-SiCPP9,所有成员均定位在细胞核,蛋白质二级结构中无规则卷曲占比最重。(2)谷子CPP蛋白可分为4个亚家族,相同亚家族之间保守基序和结构域的数目及分布相似。(3)启动子分析发现谷子CPP家族中存在大量光、生长发育、激素及胁迫响应元件。(4)谷子CPP家族成员在根、茎、叶和穗中差异表达,SiCPP5、SiCPP6、SiCPP7和SiCPP8对外源硒响应最强烈。【结论】谷子CPP家族成员具有组织表达特异性,且对外源硒存在不同程度响应。

谷子细胞色素P450基因与株高的关联分析

通过对160份谷子材料进行重测序,在CYP450基因内共检测到48个SNP位点,所有位点都位于编码区。基于SNP位点的群体结构分析将160份谷子材料划分为2个群,第一群包括137个品种,主要来自河南省、河北省、内蒙古等地方,第二群包括23个品种,主要来自辽宁省、陕西省等地方。对谷子生长素应答蛋白基因的48个SNP位点来进行的连锁不平衡的结构分析,当R^(2)=1时,有一组明显较大的连锁不平衡的结构,包括7个SNP位点,分别为SNP-3、SNP-8、SNP-12、SNP-13、SNP-14、SNP-18、SNP-35,这些基因位点都位在于编码区外显子中。GLM模型和MLM模型共有的谷子CYP450基因SNP位点有7个,分别是SNP-16、SNP-17、SNP-21、SNP-28、SNP-31、SNP-39、SNP-43。在这7个谷子CYP450基因SNP位点3个为错义突变,分别是SNP-16氨基酸由Leu突变为Ile,SNP-17氨基酸由Leu突变为Val,SNP-28氨基酸由Gly突变为Ser,其余4个为无义突变。本研究初步证明谷子CYP450基因与株高有密切关联,为进一步研究CYP450基因对谷子株高的调控作用提供了有力的依据。