α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from d...α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.展开更多
China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cu...China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.展开更多
Three pairs of near-isogenic lines with different genetic backgrounds of yellow-seededand black-seeded rape (Brassica napus L.) were used as experiment materials to study therelationship of color formation in the seed...Three pairs of near-isogenic lines with different genetic backgrounds of yellow-seededand black-seeded rape (Brassica napus L.) were used as experiment materials to study therelationship of color formation in the seedcoat with enzyme activity and protein contentin it. The results showed that with similar genetic backgrounds, phenylalanine ammonia-lyase (PAL) and polyphenol oxidase(PPO) activities in the black-seeded lines were muchhigher than in their yellow-seeded counterparts and maximum PAL activity in the seedcoatoccurred comparatively late while no significant difference was present in glutaminesynthetase (GS) between the two types of rape. The plants were treated with red light,blue light, p-hydroxybenzoic acid (a PAL inhibitor), polyvinylpyridoxal (a PPO inhibitor),urea (a protein synthesis promoter) or chloramphenicol (CM, a plastid protein synthesisinhibitor) during seed development. It is speculated that PAL may be primarily responsiblefor coloration in the yellow seed; PPO may be the main factor contributing to thedarkness of the testa of the black genotypes; and nitrogen assimilation is, probably, notdirectly related to the difference in protein content observed between yellow- andblack-seeded genotypes, which may be induced mainly by PAL.展开更多
Long developmental stage and late harvest time of winter rapeseed (Brassica napus L.) have great negative effects on rice planting of rice-rapeseed farming system in China. Early maturity improvement of rapeseed is ne...Long developmental stage and late harvest time of winter rapeseed (Brassica napus L.) have great negative effects on rice planting of rice-rapeseed farming system in China. Early maturity improvement of rapeseed is necessary. ‘Zhongshuang 11’, an elite winter rapeseed cultivar, was used in consecutive field experiments during 2010-2012. At initial flowering stage, plants were consecutively sprayed with 0.1 mg/L 2-4-Epibrassinolide(BR) for 3 d. Two hundred sampling pods from different plants were randomly collected to measure seed related indexes with a 4 d interval from 7 to 47 d after peak anthesis (DAPA).Seed color turned light brown at 31 or 35 DAPA after BR treatment, seed dry weight (DWT)was increased while seed moisture content (SMC) was decreased during seed development.DWT almost reached the maximum value when SMC was 33.20% at 31 DAPA in 2010-2011 and 35.29% at 35 DAPA in 2011-2012 growing season after BR treatment. Similarly,the maximum values of standard germination test (SGT), accelerated aging test (AAT)and cold test (CT) were observed at 31 or 35 DAPA after BR treatment respectively. The high yield and seed oil content appeared at 31 or 35 DAPA accompanied with rapid decrease in total non-structural carbohydrate (TNC) in stems and leaves. Our study indicated that BR application advanced maturity of winter rapeseed by 4 to 8 days.展开更多
Using tracer techniques with the radioisotope 45Ca, the effects of boron supply from soil and nutrient solution on the retranslocation of 45Ca from leaves to other parts of rape plants were studied. Results indicated ...Using tracer techniques with the radioisotope 45Ca, the effects of boron supply from soil and nutrient solution on the retranslocation of 45Ca from leaves to other parts of rape plants were studied. Results indicated that only a small portion of foliar-applied 45Ca could be retranslocated to other parts of the rape plant. There was no pronounced effect of boron level in the soil on 45 Ca retranslocation. Increasing boron concentrations in the nutrient solution significantly reduced 45 Ca radioactivity in root and stem, but increased 45Ca uptake and 45 Ca translocation to the upper leaves of rape plants. It was suggested that45 Ca absorbed by newly developed roots was easily distributed to upper leaves of rape plants. Boron may alter distribution of calcium via its effect on root development or growth of newly developed roots.展开更多
Direct-sowing establishment method has great significance in improving winter oilseed rape(Brassica napus L.) production and guaranteeing edible oil security in China. However, nutrient responses on direct sown wint...Direct-sowing establishment method has great significance in improving winter oilseed rape(Brassica napus L.) production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape(DOR) performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River(RYR) to determine the effects of nitrogen(N), phosphorus(P), and potassium(K) deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment(NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1) and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.展开更多
Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent year...Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.展开更多
China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesti...China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.展开更多
Oilseed rape (Brassica napus L.) is one of the most important oil crops worldwide and provides about 50 percent of the vegetable oil supply in China (Yin et al., 2009). The development of rapeseed varieties with h...Oilseed rape (Brassica napus L.) is one of the most important oil crops worldwide and provides about 50 percent of the vegetable oil supply in China (Yin et al., 2009). The development of rapeseed varieties with higher yield is an effective measure to optimize balance between the supply and demand of edible vegetable oil. In oilseed rape, the number of silique per plant (SP) contributes most to the yield performance (Diepenbrock, 2000). However, compared with the other two yield-component traits, seeds per silique (SS) and seed weight (SW), SP is more sensitive to environmental changes (Li et al., 2007; Shi et al., 2009). Therefore, it is difficult to perform the genetic improvement on SP trait directly in oilseed rape.展开更多
Nanoplastic pollution has become a significant problem in farmland systems worldwide.However,research on the effects of nanoplastics(NPs)with different charges on field crops is still limited.In our study,NPs with dif...Nanoplastic pollution has become a significant problem in farmland systems worldwide.However,research on the effects of nanoplastics(NPs)with different charges on field crops is still limited.In our study,NPs with different charges,including unmodified polystyrene nanoplastics(PS),positively charged polystyrene nanoplastics(PS-NH_(2)),and negatively charged polystyrene nanoplastics(PSSO3H),were investigated for their impacts on seed germination and seedling growth of rape.The results showed that seed water uptake(after 12 h),seed germination,seed vigour,and relative root elongation were all significantly reduced under exposure to NPs(200 mg/L).Similarly,remarkable decreases in plant biomass(root weight,shoot weight),growth(root length,plant height),photosynthesis ability(chlorophyll a,chlorophyll b,carotenoids),essential nutrient uptake(Fe,Mn,Zn,Cu),and plant quality(soluble protein,soluble sugar,crude fibre content)of rape seedlings were also observed after exposure to NPs.Among the three kinds of NPs,PS-NH_(2)showed stronger effects.Moreover,superoxide dismutase,peroxidase,and catalase activities of rape seedlings were changed,and the content of malondialdehyde was significantly increased under exposure to NPs.Furthermore,positively charged PS-NH_(2)showed stronger effects on the phenotype,physiology,biochemistry,nutrient uptake,and plant quality of rape.Notably,a comprehensive toxicity evaluation revealed that PS-NH_(2)had the strongest toxicity to rape.The present study provides important implications for the interaction and risk assessment of NPs and crops in soil-plant systems.展开更多
为探明不同氮肥用量对冬油菜籽粒产量和品质的影响,于2019/2020以及2020/2021年在湖北省武穴市开展田间试验,试验设置0、90、180、270、360 kg N hm^(-2)5个氮肥施用水平。在成熟期测定油菜籽产量、氮含量和油菜籽品质指标。结果表明,...为探明不同氮肥用量对冬油菜籽粒产量和品质的影响,于2019/2020以及2020/2021年在湖北省武穴市开展田间试验,试验设置0、90、180、270、360 kg N hm^(-2)5个氮肥施用水平。在成熟期测定油菜籽产量、氮含量和油菜籽品质指标。结果表明,施氮显著提高冬油菜籽粒产量及氮含量,与不施氮相比,氮肥施用后平均增产1548 kg hm^(-2),平均增产率达32.9%,在施氮量为0~270 kg N hm^(-2)范围内,油菜籽产量随氮肥施用量显著增加,继续增施氮肥,油菜籽产量无明显变化或有下降趋势,施氮主要通过提高单株角果数来提高油菜籽粒产量。施氮显著增加了籽粒蛋白质含量,当施氮量达270 kg N hm^(-2)时籽粒氮含量和蛋白质含量最高。施氮显著降低籽粒含油量,氮肥用量每增加100 kg N hm^(-2),籽粒含油量下降1.6个百分点。随着氮肥用量的增加,籽粒硫甙、油酸、亚麻酸、芥酸以及饱和脂肪酸(棕榈酸和硬脂酸)呈升高趋势,亚油酸呈降低趋势,油菜籽粒品质整体呈降低趋势。综上所述,以追求高品质食用油为目标,同时兼顾油菜籽粒产量,氮肥适宜用量约为180kgNhm^(-2);以追求油菜籽粒产量并考虑油菜饼粕作饲料为目标时,氮肥适宜用量约为270 kg N hm^(-2)。展开更多
基金This work was supported by the National Natural Science Foundation of China(31871549,32001441 and 32272015)the Chongqing Research Program of Basic Research and Frontier Technology,China(cstc2015jcyjBX0143)+2 种基金the Fundamental Research Funds for the Central Universities,China(XDJK2020C038)the National Key R&D Program of China(2016YFD0100506)the Young Eagles Program of Chongqing Municipal Commission of Education,China(CY220219)。
文摘α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.
基金supported by the Special Funding for Modern Agricultural Technical System of China (Rapeseed)the National Natural Science Foundation of China (31071372)
文摘China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.
基金The research is part of the 863 Program in the Ministry of Science and Technology(2002AA207009,2003AA207131)the Key Program in the National Natural Science Foundation of China(30330400)the Foundation Program in the Committee of Science and Technology of Chongqing,China(2002-7274).
文摘Three pairs of near-isogenic lines with different genetic backgrounds of yellow-seededand black-seeded rape (Brassica napus L.) were used as experiment materials to study therelationship of color formation in the seedcoat with enzyme activity and protein contentin it. The results showed that with similar genetic backgrounds, phenylalanine ammonia-lyase (PAL) and polyphenol oxidase(PPO) activities in the black-seeded lines were muchhigher than in their yellow-seeded counterparts and maximum PAL activity in the seedcoatoccurred comparatively late while no significant difference was present in glutaminesynthetase (GS) between the two types of rape. The plants were treated with red light,blue light, p-hydroxybenzoic acid (a PAL inhibitor), polyvinylpyridoxal (a PPO inhibitor),urea (a protein synthesis promoter) or chloramphenicol (CM, a plastid protein synthesisinhibitor) during seed development. It is speculated that PAL may be primarily responsiblefor coloration in the yellow seed; PPO may be the main factor contributing to thedarkness of the testa of the black genotypes; and nitrogen assimilation is, probably, notdirectly related to the difference in protein content observed between yellow- andblack-seeded genotypes, which may be induced mainly by PAL.
文摘Long developmental stage and late harvest time of winter rapeseed (Brassica napus L.) have great negative effects on rice planting of rice-rapeseed farming system in China. Early maturity improvement of rapeseed is necessary. ‘Zhongshuang 11’, an elite winter rapeseed cultivar, was used in consecutive field experiments during 2010-2012. At initial flowering stage, plants were consecutively sprayed with 0.1 mg/L 2-4-Epibrassinolide(BR) for 3 d. Two hundred sampling pods from different plants were randomly collected to measure seed related indexes with a 4 d interval from 7 to 47 d after peak anthesis (DAPA).Seed color turned light brown at 31 or 35 DAPA after BR treatment, seed dry weight (DWT)was increased while seed moisture content (SMC) was decreased during seed development.DWT almost reached the maximum value when SMC was 33.20% at 31 DAPA in 2010-2011 and 35.29% at 35 DAPA in 2011-2012 growing season after BR treatment. Similarly,the maximum values of standard germination test (SGT), accelerated aging test (AAT)and cold test (CT) were observed at 31 or 35 DAPA after BR treatment respectively. The high yield and seed oil content appeared at 31 or 35 DAPA accompanied with rapid decrease in total non-structural carbohydrate (TNC) in stems and leaves. Our study indicated that BR application advanced maturity of winter rapeseed by 4 to 8 days.
基金supported by the Nationa1 Natura1 Science Foundation of China(39770439).
文摘Using tracer techniques with the radioisotope 45Ca, the effects of boron supply from soil and nutrient solution on the retranslocation of 45Ca from leaves to other parts of rape plants were studied. Results indicated that only a small portion of foliar-applied 45Ca could be retranslocated to other parts of the rape plant. There was no pronounced effect of boron level in the soil on 45 Ca retranslocation. Increasing boron concentrations in the nutrient solution significantly reduced 45 Ca radioactivity in root and stem, but increased 45Ca uptake and 45 Ca translocation to the upper leaves of rape plants. It was suggested that45 Ca absorbed by newly developed roots was easily distributed to upper leaves of rape plants. Boron may alter distribution of calcium via its effect on root development or growth of newly developed roots.
基金supported by the National Key Technologies R&D Program of China during the 11th Five-Year Plan period (2010BAD01B05)the Earmarked Fund for China Agriculture Research System (CARS-13)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1247)the Fundamental Research Funds for the Central Universities,China (2013PY113)
文摘Direct-sowing establishment method has great significance in improving winter oilseed rape(Brassica napus L.) production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape(DOR) performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River(RYR) to determine the effects of nitrogen(N), phosphorus(P), and potassium(K) deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment(NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1) and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.
基金The research was supported by the State Key Basic Research and Development Plan of China(2004CB 117200,2002CB111300)the Hi-Tech Research and De-velopment Program of China(2004AA21111)+1 种基金the China Scholarship Council,the Sino-Polish Scientific and Technological Cooperation 2004 2006(3 1-23B)the National Natural Science Foundation of China(30000107).
文摘Sclerotinia sclerotiorum (Lib.) de Bary, as an ubiquitous phytopathogenic Ascomycete fungus capable of infecting a wide range of plants, has increased in importance for oilseed rape production worldwide in recent years. The objective of this research was to determine the effectiveness of two measurements of disease rating in predicting the field reaction of cultivars to sclerotinia stem rot. One hundred and ten cultivars or lines of oilseed rape were repeatedly evaluated the disease severity index (DSI) and lesion length for their resistance to nine isolates of S. sclerotiorum in two field stations. There were greatly significant differences between two stations, among isolates, among population of cultivars for the disease severity index and lesion length, and also significant station×isolate interaction for lesion length and population×isolate interactions for DSI and lesion length, but interactions of station×isolate for DSI were not significant. Cultivars such as Pomorzanin and Lisek consistently had the lowest disease severity ratings in the field tests. However, most of cultivars were susceptible to sclerotinia stem rot in the field test. A positive correlation between the mean DSI and lesion length was found for both isolates (Sc23 and B1). The correlations ranged from 0.23 to 0.83 at various plots, with nine of the twelve correlations significant. The correlations for disease caused by different fungal isolates were statistically significant difference. These correlations ranged from -0.44 to 0.90, with nine of the thirty-two correlations significant. It indicated that resistance to some isolates was significantly correlated and selection of some varieties for resistance to one isolate appeared to improve resistance to other isolates.
基金financial support provided by the National Key Research and Development Program of China (2016YFD0702100)the Special Funds for the Construction of Modern Agricultural Industrial Technology System (CARS-13)
文摘China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.
基金supported by the Hi-Tech Research and Development program of China (Grant No. 2011AA10A104)the National Natural Science Foundation of China (Grant Nos. 31171589 and 31201244)+1 种基金the National Basic Research Program (Grant No. 2011CB109302)the Special Fund for Agroscientific Research in the Public Interest (Grant No. 2101203032)
文摘Oilseed rape (Brassica napus L.) is one of the most important oil crops worldwide and provides about 50 percent of the vegetable oil supply in China (Yin et al., 2009). The development of rapeseed varieties with higher yield is an effective measure to optimize balance between the supply and demand of edible vegetable oil. In oilseed rape, the number of silique per plant (SP) contributes most to the yield performance (Diepenbrock, 2000). However, compared with the other two yield-component traits, seeds per silique (SS) and seed weight (SW), SP is more sensitive to environmental changes (Li et al., 2007; Shi et al., 2009). Therefore, it is difficult to perform the genetic improvement on SP trait directly in oilseed rape.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.U20A20115 and 42007112)the Major Technology Innovation Project of Shandong Province(No.2020CXGC011403).
文摘Nanoplastic pollution has become a significant problem in farmland systems worldwide.However,research on the effects of nanoplastics(NPs)with different charges on field crops is still limited.In our study,NPs with different charges,including unmodified polystyrene nanoplastics(PS),positively charged polystyrene nanoplastics(PS-NH_(2)),and negatively charged polystyrene nanoplastics(PSSO3H),were investigated for their impacts on seed germination and seedling growth of rape.The results showed that seed water uptake(after 12 h),seed germination,seed vigour,and relative root elongation were all significantly reduced under exposure to NPs(200 mg/L).Similarly,remarkable decreases in plant biomass(root weight,shoot weight),growth(root length,plant height),photosynthesis ability(chlorophyll a,chlorophyll b,carotenoids),essential nutrient uptake(Fe,Mn,Zn,Cu),and plant quality(soluble protein,soluble sugar,crude fibre content)of rape seedlings were also observed after exposure to NPs.Among the three kinds of NPs,PS-NH_(2)showed stronger effects.Moreover,superoxide dismutase,peroxidase,and catalase activities of rape seedlings were changed,and the content of malondialdehyde was significantly increased under exposure to NPs.Furthermore,positively charged PS-NH_(2)showed stronger effects on the phenotype,physiology,biochemistry,nutrient uptake,and plant quality of rape.Notably,a comprehensive toxicity evaluation revealed that PS-NH_(2)had the strongest toxicity to rape.The present study provides important implications for the interaction and risk assessment of NPs and crops in soil-plant systems.
文摘为探明不同氮肥用量对冬油菜籽粒产量和品质的影响,于2019/2020以及2020/2021年在湖北省武穴市开展田间试验,试验设置0、90、180、270、360 kg N hm^(-2)5个氮肥施用水平。在成熟期测定油菜籽产量、氮含量和油菜籽品质指标。结果表明,施氮显著提高冬油菜籽粒产量及氮含量,与不施氮相比,氮肥施用后平均增产1548 kg hm^(-2),平均增产率达32.9%,在施氮量为0~270 kg N hm^(-2)范围内,油菜籽产量随氮肥施用量显著增加,继续增施氮肥,油菜籽产量无明显变化或有下降趋势,施氮主要通过提高单株角果数来提高油菜籽粒产量。施氮显著增加了籽粒蛋白质含量,当施氮量达270 kg N hm^(-2)时籽粒氮含量和蛋白质含量最高。施氮显著降低籽粒含油量,氮肥用量每增加100 kg N hm^(-2),籽粒含油量下降1.6个百分点。随着氮肥用量的增加,籽粒硫甙、油酸、亚麻酸、芥酸以及饱和脂肪酸(棕榈酸和硬脂酸)呈升高趋势,亚油酸呈降低趋势,油菜籽粒品质整体呈降低趋势。综上所述,以追求高品质食用油为目标,同时兼顾油菜籽粒产量,氮肥适宜用量约为180kgNhm^(-2);以追求油菜籽粒产量并考虑油菜饼粕作饲料为目标时,氮肥适宜用量约为270 kg N hm^(-2)。