Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the...Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the oil(Warner et al.2008;Liang et al.2017;Doureradjou and Koner 2020;Ghasemzadeh et al.2020).The fatty acid composition of rice bran oil is one of the healthiest edible oils due to its balanced source of saturated,monounsaturated,and polyunsaturated fatty acids with a ratio of 0.6:1.1:1(Liang et al.2017;Awad et al.2022).展开更多
Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC tran...Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC transcription factor ANAC050 in the regulation of Al tolerance.ANAC050 was located in the nucleus and displayed constitutive expression in the silique,flower,leaf,stem,and root,despite the fact that Al stress decreased its expression and protein accumulation.When compared with the Columbia ecotype wild-type,anac050 mutants that lacked function of ANAC050 exhibited Al sensitivity phenotype,while transgenic lines that overexpressed ANAC050 showed an Al-resistant phenotype,indicating the favorable influence of ANAC050 on preserving Al tolerance in plants.Further analysis indicated that anac050 mutants accumulated more Al in roots,implying that ANAC050 may confer a potential operation of an Al exclusion mechanism.Interestingly,anac050 mutants had down-regulated the expression of the genes encoding MULTIDRUG AND TOXIC COMPOUND EXTRUSION(MATE)and AL-ACTIVATED MALATE TRANSPORTER(ALMT1),which were involved in the secretion of citrate and malate,even though there was no evidence of a direct interaction between them,suggesting ANAC050 may mediate the secretion of citrate and malate indirectly.Together with the decreased hemicellulose content,lower Al content was also discovered in root cell walls and hemicelluloses of anac050 mutants,pointing to a potential interaction between ANAC017 and XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE(XTH).Although there was no evidence of a direct interaction between ANAC050 and XTH31,it is worth mentioning that the expression of XTH31,which is essential for xyloglucan modification,was down-regulated in anac050 mutants irrespective of the amount of Al given.In conclusion,our findings showed that ANAC050 contributed to Al resistance by indirect control of the release of organic acids and the accumulation of cell wall hemicelluloses.展开更多
Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants o...Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants of barley yield and quality.The identification and cloning of genes related to kernel traits,along with the detection of superior alleles,are fundamental for marker-assisted selection in barley breeding.This study presents the cloning of HvGL7-2H from barley,based on the known rice GL7 gene.The functional significance of HvGL7-2H in grain length was confirmed through ethyl methane sulfonate(EMS)mutants of the barley landrace“Hatiexi”.A candidate gene-based association analysis was conducted using a panel of 363 barley accessions to identify superior haplotypes for HvGL7-2H.The analysis revealed that Hap3 represented the superior haplotype for both grain length and TGW,while Hap4 emerged as the superior haplotype for TGW.These findings indicate that genotypes carrying the superior allele serve as valuable genetic resources,and the molecular markers identified herein will facilitate grain size and yield improvement in barley breeding programs.展开更多
Seed storage proteins and their abundance are closely related to the formation of rice quality and grain size.A better understanding of the molecular basis of seed storage proteins will provide important information f...Seed storage proteins and their abundance are closely related to the formation of rice quality and grain size.A better understanding of the molecular basis of seed storage proteins will provide important information for developing new rice breeding strategies.In this study,we report that a seed storage protein albumin,named OsRAL5,positively regulates rice quality and grain size.OsRAL5 is specifically expressed during the grain-filling stage,suggesting its key role in regulating seed development.Gene editing of OsRAL5 using the CRISPR/Cas9 system diminished grain size and weight,resulting in the development of white-core endosperm and a reduction in eating and cooking quality(ECQ).Conversely,the endosperm appearance became transparent,and both grain weight and ECQ improved in the OsRAL5 over-expressed lines.The major seed storage components differed significantly between the OsRAL5-edited(dOsRAL5-TS)and OsRAL5-overexpressed(OsRAL5-OE)lines compared with the wild type.The protein and total lipid contents both decreased in the dOsRAL5-TS lines and increased in the OsRAL5-OE lines.Collectively,the over-expression of OsRAL5 significantly increased nutritional content and simultaneously improved yield and ECQ.These results imply that OsRAL5 might be a promising candidate gene for breeding super rice varieties with increased yield potential and superior quality.展开更多
The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,w...The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.展开更多
Green-revertible albino is a novel type of chlorophyll deficiency in rice （Oryza sativa L.）, which is helpful for further research in chlorophyll synthesis and chloroplast development to illuminate their molecular m...Green-revertible albino is a novel type of chlorophyll deficiency in rice （Oryza sativa L.）, which is helpful for further research in chlorophyll synthesis and chloroplast development to illuminate their molecular mechanism. In the previous study, we had reported a single recessive gene, gra（t）, controlling this trait on the long arm of chromosome 2. In this paper, we mapped the gra（t） gene using 1,936 recessive individuals with albino phenotype in the F2 population derived from the cross between themo-photoperiod-sensitive genic male-sterile （T/PGMS） line Pei＇ai 64S and the spontaneous mutant Qiufeng M. Eventually, it was located to a confined region of 42.4 kb flanked by two microsatellite markers RM2-97 and RM13553. Based on the annotation results of RiceGAAS system, 11 open reading frames （ORFs） were predicted in this region. Among them, ORF6 was the most possible gene related to chloroplast development, which encoded the chloroplast protein synthesis elongation factor Tu in rice. Therefore, we designated it as the candidate gene of gra（t）. Sequence analysis indicated that only one base substitution C to T occurred in the coding region, which caused a missense mutation （Thr to Ile） in gra（t） mutant. These results are very valuable for further study on gra（t） gene.展开更多
To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure ...To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure of two Waxy(Wx) alleles japonica rice cultivars Nanjing 9108(NJ9108) and Huaidao 5(HD5) under four N rates(0, 150, 300, and 450 kg ha^-1). Sensory and pasting properties of the two cultivars varied depending on N rates. Compared with the control(0 kg ha^-1), the overall eating quality and sensory value were significantly decreased under the N rates of 300 and 450 kg ha^-1. Further, conventional descriptive analysis showed that the stickiness and retrogradation of cooked rice were significantly decreased. These results indicated that application of N fertilizer seems to affect the texture of cooked rice, causing it to be less sticky, lowering its retrogradation, and consequently reducing its palatability. Results from rapid visco analyzer(RVA) revealed that the peak and breakdown viscosities significantly decreased, while the setback viscosity and peak time increased under the N rates of 300 and 450 kg ha^-1. However, no significant difference was observed when the N rate was 150 kg ha^-1, indicating that less N fertilization can maintain rice ECQ. As the N rate increasing, protein content increased, whereas apparent amylose content, starch content, and gel consistency almost unchanged. Interestingly, compared with the control, under N treatments, the percentage of short amylopectin branches in NJ9108 was decreased, but increased in HD5, as controlled by amylopectin synthesis-related genes. Notably, SSI and BEIIb were down-regulated in NJ9108, whereas BEIIb was up-regulated in HD5. Thus, the palatability of both rice cultivars was significantly decreased under excessive N fertilization as a consequence of reduced stickiness and retrogradation of the cooked rice, which might have resulted from an elevated protein content and altered amylopectin fine structure. In addition, amylopectin synthesis appeared to be affected by N fertilizer and the genotype of the rice cultivar.展开更多
Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of g...Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis（PCA）. Analysis of molecular variance（AMOVA） revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index（F ST） suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.展开更多
Better understanding of genotype-by-environment interaction （GEI） is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments. To elucidate the ...Better understanding of genotype-by-environment interaction （GEI） is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments. To elucidate the genetic basis of the plant and ear height, 2 F2：3 populations were derived from the crosses of Qi 319 × Huangzaosi （Q/H） and Ye 478 × Huangzaosi （Y/H） with 230 and 235 families, respectively, and their parents were evaluated under 3 diverse environments in Henan, Beijing, and Xinjiang, China during the year of 2007 and 2008, and all the lines were also evaluated under water stress environment. The mapping results showed that a total of 21 and 12 QTLs were identified for plant height in the Q/H and Y/H population, respectively, and 24 and 13 QTLs for ear height, respectively. About 56 and 73% of the QTLs for 2 traits did not present significant QTL-by-environment interaction （QE1） in the normal joint analyses for Q/H and Y/H population, respectively, and about 73% of the QTLs detected did not show significant QEI according to joint analyses for stress condition in Q/H. Most of the detected major QTLs exhibited high stability across different environments. Besides, several major QTLs were detected with large and consistent effect under normal condition （Chr. 6 and 7 in Q/H; Chr. 1, 3 and 9 in Y/H）, or across 2 water regimes （Chr. 1, 8 and 10 for in Q/H）. There were several constitutive QTLs （3 for Q/H and 1 for Y/H） with no or minor QTL-by-environment for the 2 populations. Finally, we found several genomic regions （Chr. 1, 10, etc.） to be co-located across the populations, which could provide useful reference for genetic improvement of these traits in maize breeding programs. Comparative genomic analysis revealed that 3 genes/genetic segments associated with plant height in rice were orthologous to these 3 identified genomic regions carrying the major QTLs for plant and ear height on Chr. 1, 6, and 8, respectively.展开更多
In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We conc...In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We concluded that selection of parents with good comprehensive traits and complementary advantages and disadvantages of both parents in the hybrid combination, and early selection of high heritability traits in earlier segregating generations could significantly improve the breeding efficiency. The use of closely-linked functional markers in pyramiding of multiple genes could greatly increase breeding efficiency, avoiding time-consuming and laborious steps that were used in traditional breeding program. It is also important to coordinate the yield components with variety characteristics such as yield stability, wide adaptability, lodging resistance, and an attractive grain appearance during late growth stage of rice.展开更多
Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve ...Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.展开更多
The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such a...The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such as brewing. In this study, knockout of the Wx gene with CRISPR/Cas9 technology was conducted in two elite japonica rice lines, Huaidao 5(HD5) and Suken 118(SK118), aiming to develop elite sticky rice varieties. We achieved six homozygous T_0 plants with more than 200 bp deletion in the Wx gene, as well as 36 wx-HD5 and 18 wx-SK118 homozygous transgene-free plants in the T_1 generation. The seeds of all the mutants were white and opaque, similar to those of sticky rice, and contained only 2.6%–3.2% amylose. Results of scanning electron microscopy showed that the quality of rice did not change. In conclusion, we successfully developed two elite sticky rice varieties.展开更多
Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities...Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.展开更多
Plant temperature （Tp） and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile （TGMS） rice line, Pei＇ai 64S. Significant differences in t...Plant temperature （Tp） and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile （TGMS） rice line, Pei＇ai 64S. Significant differences in the daily change of temperature were detected between Tp and air temperature at the height of 150 cm （TA）. From 8：00 to 20：00, Tp was lower than TA, but they were similar during 21：00 to next 7：00. The maximum Tp occurred one hour earlier than the maximum TA, though they both reached the minimum at 6：00. Tp fluctuated less than TA. At the same height, during 6：00-13：00, Tp was higher than air temperature （Ta）, and Tp reached the maximum one hour earlier than Ta. During the rest time on sunny day, Tp was close to or even a little lower than Ta. On overcast day, Tp was higher than Ta in the whole day, and both maximized at the same time. In addition, Tp was regulated by solar radiation, cloudage and wind speed in daytime, and by irrigation water at night. The present study indicated that a TA of 29.6℃ was the critical point, at which Tp was increased or decreased by irrigation water. Tp and the difference between water and air temperatures showed a conic relation. Tp fluctuation was also regulated by the absorption or reflection of solar radiation by leaves during daytime and release of heat energy during nighttime. By analysis on correlation and regression simulation, two models of Tp were established.展开更多
Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solu...Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solution with NH4NO3 or(NH4)2SO4 as the nitrogen source for six weeks in pools.A portion of the Guodao 1 seedlings after treatment in the pools for four weeks were transferred to a split-root system at different dissolved oxygen contents and cultured for an additional two weeks.Biomass,root morphological traits and nitrogen accumulation were recorded.Under the low rhizosphere dissolved oxygen content(0-1.0 mg/L),plant biomass was significantly increased under NH4NO3-N supply by about 69% in Guodao 1 and 41% in Xiushui 09 compared with those under NH4+-N alone.Similar results were observed for root number,maximum root length,root dry weight and root activity.Nitrogen accumulations in roots and shoots were increased by 60% and 52% for Guodao 1,and by 41% and 33% for Xiushui 09,respectively,in the NH4NO3-N treatment.In the split-root system,the high rhizosphere dissolved oxygen content(8.0-9.0 mg/L) promoted root growth and development.Root biomass was increased by 21.6%,root number by 27%,maximum root length by 14%,and root volume by 10%.Moreover,nitrogen accumulation in roots was increased by 11% under high rhizosphere oxygen conditions.In conclusion,enhanced dissolved oxygen content and combined ammonium-nitrate nitrogen source have positive effects on root growth and nitrogen accumulation of rice plants.展开更多
Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and Gl...Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and GluB5, which locates on the short arm of chromosome 2. To improve the selection efficiency in low glutelin-content rice breeding, two molecular markers designated as InDel-Lgc1-1 and InDel-Lgc1-2 were developed to detect the low glutelin-content gene Lgc1. A double PCR detection indicated that combined use of the two markers could easily distinguish the genotypes of Lgc1 from different rice varieties. Therefore, as a simple and low-cost technique, the molecular marker could be widely used to identify different varieties with Lgc1 gene and applied in marker-assisted selection of low glutelin-content rice.展开更多
Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and Iow-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In ...Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and Iow-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In continuous backcross and selfcross generations, the related molecular markers with Stvobi and Wx-mq genes were utilized for genotypic detection by associated with resistance identification of rice stripe disease and agronomic traits selection. Finally, 10 improved lines with homozygous genotype Stv-b^i Stv-b^iWx-mqWx-mq were obtained from BC3F4 generation. The results of comparative analysis indicated that most characters of these lines were consistent with those of recipient parent Wuyujing 3, except for the improved resistance, appearance and eating quality. By evaluation of the comprehensive performance of them, two excellent lines K01 and K04 were selected for further experiments.展开更多
In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selecte...In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction （61.7-89.2%） was observed in japonica rice,when cytokinin was added at lower concentration （0.3 mg L-1 6-BA） in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins （2 mg L-1 6-BA,0.5 mg L-1 KT） and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.展开更多
The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in f...The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.展开更多
Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New...Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg.展开更多
基金supported by the National Natural Science Foundation of China(32201861)Ministry of Agriculture and Rural Affairs of China,the Key Research and Development Program of Jiangsu Province,China(BE2022383)the Zhongshan Biological Breeding Laboratory,China(ZSBBLKY2023-04-1)。
文摘Rice(Oryza sativa L.)is a globally important food crop.Its bran oil has high nutritional value,but with a low content of oleic acid and a high content of linoleic acid,which affects the stability and shelf life of the oil(Warner et al.2008;Liang et al.2017;Doureradjou and Koner 2020;Ghasemzadeh et al.2020).The fatty acid composition of rice bran oil is one of the healthiest edible oils due to its balanced source of saturated,monounsaturated,and polyunsaturated fatty acids with a ratio of 0.6:1.1:1(Liang et al.2017;Awad et al.2022).
基金supported by the Key Project of the National Natural Science Foundation of China(No.42230711)。
文摘Aluminium(Al)toxicity is one of the key factors limiting crop output in acidic soils,but until now little has been known about how Al is regulated transcriptionally in plants.This study identified Arabidopsis NAC transcription factor ANAC050 in the regulation of Al tolerance.ANAC050 was located in the nucleus and displayed constitutive expression in the silique,flower,leaf,stem,and root,despite the fact that Al stress decreased its expression and protein accumulation.When compared with the Columbia ecotype wild-type,anac050 mutants that lacked function of ANAC050 exhibited Al sensitivity phenotype,while transgenic lines that overexpressed ANAC050 showed an Al-resistant phenotype,indicating the favorable influence of ANAC050 on preserving Al tolerance in plants.Further analysis indicated that anac050 mutants accumulated more Al in roots,implying that ANAC050 may confer a potential operation of an Al exclusion mechanism.Interestingly,anac050 mutants had down-regulated the expression of the genes encoding MULTIDRUG AND TOXIC COMPOUND EXTRUSION(MATE)and AL-ACTIVATED MALATE TRANSPORTER(ALMT1),which were involved in the secretion of citrate and malate,even though there was no evidence of a direct interaction between them,suggesting ANAC050 may mediate the secretion of citrate and malate indirectly.Together with the decreased hemicellulose content,lower Al content was also discovered in root cell walls and hemicelluloses of anac050 mutants,pointing to a potential interaction between ANAC017 and XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE(XTH).Although there was no evidence of a direct interaction between ANAC050 and XTH31,it is worth mentioning that the expression of XTH31,which is essential for xyloglucan modification,was down-regulated in anac050 mutants irrespective of the amount of Al given.In conclusion,our findings showed that ANAC050 contributed to Al resistance by indirect control of the release of organic acids and the accumulation of cell wall hemicelluloses.
基金financially supported by the National Natural Science Foundation of China(31771774)the National Key Research and Development Program of China(2018YFD1000700 and 2018YFD1000706)+1 种基金the Young Top-notch Talent Cultivation Program of Hubei Province,Hubei Hongshan Laboratory,Chinathe China Agriculture Research System of Ministry of Agriculture and Rural Affairs(CARS-05).
文摘Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants of barley yield and quality.The identification and cloning of genes related to kernel traits,along with the detection of superior alleles,are fundamental for marker-assisted selection in barley breeding.This study presents the cloning of HvGL7-2H from barley,based on the known rice GL7 gene.The functional significance of HvGL7-2H in grain length was confirmed through ethyl methane sulfonate(EMS)mutants of the barley landrace“Hatiexi”.A candidate gene-based association analysis was conducted using a panel of 363 barley accessions to identify superior haplotypes for HvGL7-2H.The analysis revealed that Hap3 represented the superior haplotype for both grain length and TGW,while Hap4 emerged as the superior haplotype for TGW.These findings indicate that genotypes carrying the superior allele serve as valuable genetic resources,and the molecular markers identified herein will facilitate grain size and yield improvement in barley breeding programs.
基金supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20211137)China Agriculture Research System(Grant No.CARS-01)。
文摘Seed storage proteins and their abundance are closely related to the formation of rice quality and grain size.A better understanding of the molecular basis of seed storage proteins will provide important information for developing new rice breeding strategies.In this study,we report that a seed storage protein albumin,named OsRAL5,positively regulates rice quality and grain size.OsRAL5 is specifically expressed during the grain-filling stage,suggesting its key role in regulating seed development.Gene editing of OsRAL5 using the CRISPR/Cas9 system diminished grain size and weight,resulting in the development of white-core endosperm and a reduction in eating and cooking quality(ECQ).Conversely,the endosperm appearance became transparent,and both grain weight and ECQ improved in the OsRAL5 over-expressed lines.The major seed storage components differed significantly between the OsRAL5-edited(dOsRAL5-TS)and OsRAL5-overexpressed(OsRAL5-OE)lines compared with the wild type.The protein and total lipid contents both decreased in the dOsRAL5-TS lines and increased in the OsRAL5-OE lines.Collectively,the over-expression of OsRAL5 significantly increased nutritional content and simultaneously improved yield and ECQ.These results imply that OsRAL5 might be a promising candidate gene for breeding super rice varieties with increased yield potential and superior quality.
基金supported by the Zhongshan Biological Breeding Laboratory,China(Grant No.ZSBBL-KY2023-07)the Jiangsu Agricultural Science and Technology Innovation Fund,China(Grant No.CX(22)3138)+1 种基金the National Natural Science Foundation of China(Grant Nos.32101736,32002124)the Jiangsu Provincial Key Research and Development Program,China(Grant No.BE2021360-2).
文摘The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.
基金supported by the National High-tech Research and Development Program of China (863 Program) (No. 2006AA100101)the National Science and Technology Support Program (No. 2006BAD01A01-5)+1 种基金Special Program for Rice Scientific Research of Ministry of Agriculture (No. nyhyzx 07-001-006)Super Rice Breeding and Demonstration Program of Ministry of Agriculture, and Jiangsu Selfinnovation Fund for Agricultural Science and Technology (No. CX[08]603).
文摘Green-revertible albino is a novel type of chlorophyll deficiency in rice （Oryza sativa L.）, which is helpful for further research in chlorophyll synthesis and chloroplast development to illuminate their molecular mechanism. In the previous study, we had reported a single recessive gene, gra（t）, controlling this trait on the long arm of chromosome 2. In this paper, we mapped the gra（t） gene using 1,936 recessive individuals with albino phenotype in the F2 population derived from the cross between themo-photoperiod-sensitive genic male-sterile （T/PGMS） line Pei＇ai 64S and the spontaneous mutant Qiufeng M. Eventually, it was located to a confined region of 42.4 kb flanked by two microsatellite markers RM2-97 and RM13553. Based on the annotation results of RiceGAAS system, 11 open reading frames （ORFs） were predicted in this region. Among them, ORF6 was the most possible gene related to chloroplast development, which encoded the chloroplast protein synthesis elongation factor Tu in rice. Therefore, we designated it as the candidate gene of gra（t）. Sequence analysis indicated that only one base substitution C to T occurred in the coding region, which caused a missense mutation （Thr to Ile） in gra（t） mutant. These results are very valuable for further study on gra（t） gene.
基金funded by the China Postdoctoral Science Foundation(2017M611753)the earmarked fund for Agriculture Research System of China(CARS-01-62)+3 种基金the National Key R&D Program of China(2015BAD01B02)the Natural Science Foundation of Jiangsu Province,China(BK20180302)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX[17]3009)the Project of Henan Key Laboratory of Tea Plant Comprehensive Utilization in South Henan,China(HNKLTCU2018004)。
文摘To understand the effect of nitrogen(N) fertilizer on rice(Oryza sativa L.) eating and cooking quality(ECQ). Here, we investigated the ECQ attributes, physicochemical foundation of ECQ, and amylopectin fine structure of two Waxy(Wx) alleles japonica rice cultivars Nanjing 9108(NJ9108) and Huaidao 5(HD5) under four N rates(0, 150, 300, and 450 kg ha^-1). Sensory and pasting properties of the two cultivars varied depending on N rates. Compared with the control(0 kg ha^-1), the overall eating quality and sensory value were significantly decreased under the N rates of 300 and 450 kg ha^-1. Further, conventional descriptive analysis showed that the stickiness and retrogradation of cooked rice were significantly decreased. These results indicated that application of N fertilizer seems to affect the texture of cooked rice, causing it to be less sticky, lowering its retrogradation, and consequently reducing its palatability. Results from rapid visco analyzer(RVA) revealed that the peak and breakdown viscosities significantly decreased, while the setback viscosity and peak time increased under the N rates of 300 and 450 kg ha^-1. However, no significant difference was observed when the N rate was 150 kg ha^-1, indicating that less N fertilization can maintain rice ECQ. As the N rate increasing, protein content increased, whereas apparent amylose content, starch content, and gel consistency almost unchanged. Interestingly, compared with the control, under N treatments, the percentage of short amylopectin branches in NJ9108 was decreased, but increased in HD5, as controlled by amylopectin synthesis-related genes. Notably, SSI and BEIIb were down-regulated in NJ9108, whereas BEIIb was up-regulated in HD5. Thus, the palatability of both rice cultivars was significantly decreased under excessive N fertilization as a consequence of reduced stickiness and retrogradation of the cooked rice, which might have resulted from an elevated protein content and altered amylopectin fine structure. In addition, amylopectin synthesis appeared to be affected by N fertilizer and the genotype of the rice cultivar.
基金supported by the Hubei Engineering and Technology Research Centre of Sweetpotato,Chinathe International Cooperation Program,Ministry of Science and Technology of China (2011DFB31620)+3 种基金the Introduction and Utiliztion of Sweetpotato Resources in USA (2013-Z61)the Characteristic Discipline of Hubei Academy of Agricultural Sciences,Chinathe Science and Technology Innovation Centre of Hubei Academy of Agricultural Sciences,China (2007-620-001-03)the China Agriculture Research System (CARS-11-C-15)
文摘Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis（PCA）. Analysis of molecular variance（AMOVA） revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index（F ST） suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.
基金supported by grants provided by the Ministry of Science and Technology of China(2006CB101700,2009CB118401,2006BAD13B03)National Natural Science Foundation of China(30730063)
文摘Better understanding of genotype-by-environment interaction （GEI） is expected to provide a solid foundation for genetic improvement of crop productivity especially under drought-prone environments. To elucidate the genetic basis of the plant and ear height, 2 F2：3 populations were derived from the crosses of Qi 319 × Huangzaosi （Q/H） and Ye 478 × Huangzaosi （Y/H） with 230 and 235 families, respectively, and their parents were evaluated under 3 diverse environments in Henan, Beijing, and Xinjiang, China during the year of 2007 and 2008, and all the lines were also evaluated under water stress environment. The mapping results showed that a total of 21 and 12 QTLs were identified for plant height in the Q/H and Y/H population, respectively, and 24 and 13 QTLs for ear height, respectively. About 56 and 73% of the QTLs for 2 traits did not present significant QTL-by-environment interaction （QE1） in the normal joint analyses for Q/H and Y/H population, respectively, and about 73% of the QTLs detected did not show significant QEI according to joint analyses for stress condition in Q/H. Most of the detected major QTLs exhibited high stability across different environments. Besides, several major QTLs were detected with large and consistent effect under normal condition （Chr. 6 and 7 in Q/H; Chr. 1, 3 and 9 in Y/H）, or across 2 water regimes （Chr. 1, 8 and 10 for in Q/H）. There were several constitutive QTLs （3 for Q/H and 1 for Y/H） with no or minor QTL-by-environment for the 2 populations. Finally, we found several genomic regions （Chr. 1, 10, etc.） to be co-located across the populations, which could provide useful reference for genetic improvement of these traits in maize breeding programs. Comparative genomic analysis revealed that 3 genes/genetic segments associated with plant height in rice were orthologous to these 3 identified genomic regions carrying the major QTLs for plant and ear height on Chr. 1, 6, and 8, respectively.
基金supported by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD01B02)the Special Program for Rice Scientific Research,Ministry of Agriculture,China(201603002-5-1)the Construction of Modern Agricultural and Industrial Technology System Project special fund,China(CARS01-47)
文摘In this study we report the results of a decade-long breeding program for japonica super rice made by Nanjing Branch of Chinese National Center for Rice Improvement in Jiangsu Academy of Agricultural Sciences. We concluded that selection of parents with good comprehensive traits and complementary advantages and disadvantages of both parents in the hybrid combination, and early selection of high heritability traits in earlier segregating generations could significantly improve the breeding efficiency. The use of closely-linked functional markers in pyramiding of multiple genes could greatly increase breeding efficiency, avoiding time-consuming and laborious steps that were used in traditional breeding program. It is also important to coordinate the yield components with variety characteristics such as yield stability, wide adaptability, lodging resistance, and an attractive grain appearance during late growth stage of rice.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA08040101)the Hundred Talents Program of Chinese Academy of Sciences to Q.Y. Bu+1 种基金the Natural Science Foundation of Heilongjiang (No.ZD2015005)Excellent Academic Leaders of Harbin (No.RC2014XK002003)
文摘Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.
基金supported by the National Key Research and Development Program (Grant No. 2017YFD0100403)the Jiangsu Province Key Research and Development Program (Modern Agriculture) Project (Grant No. BE2017345-2)+1 种基金the Exploratory Project of the Jiangsu Academy of Agricultural Sciences [Grant No. ZX(17)2014]the Jiangsu Province Natural Science Foundation (Grant No. BK20171326)
文摘The waxy gene(Wx) in rice, which encodes the granule bound starch synthase enzyme, is responsible for amylose synthesis. Glutinous(sticky) rice has little or no amylose that can be used in various applications, such as brewing. In this study, knockout of the Wx gene with CRISPR/Cas9 technology was conducted in two elite japonica rice lines, Huaidao 5(HD5) and Suken 118(SK118), aiming to develop elite sticky rice varieties. We achieved six homozygous T_0 plants with more than 200 bp deletion in the Wx gene, as well as 36 wx-HD5 and 18 wx-SK118 homozygous transgene-free plants in the T_1 generation. The seeds of all the mutants were white and opaque, similar to those of sticky rice, and contained only 2.6%–3.2% amylose. Results of scanning electron microscopy showed that the quality of rice did not change. In conclusion, we successfully developed two elite sticky rice varieties.
基金supported by the National Key Research and Development Program of China(2019YFD1001302 and 2019YFD1001300)National Natural Science Foundation of China(31701483 and 31601382)+2 种基金Jiangsu Agricultural Science and Technology Independent Innovation Fund[CX(19)3063]the National Technical System of Sweetpotato Industry(CARS-10-C3)Jiangsu Province Science and Technology Support Program(BK20171325)。
文摘Sweetpotato[Ipomoea batatas(L.)Lam.],a food crop with both nutritional and medicinal uses,plays essential roles in food security and health-promoting.Chlorogenic acid(CGA),a polyphenol displaying several bioactivities,is distributed in all edible parts of sweetpotato.However,little is known about the specific metabolism of CGA in sweetpotato.In this study,IbPAL1,which encodes an endoplasmic reticulum-localized phenylalanine ammonia lyase(PAL),was isolated and characterized in sweetpotato.CGA accumulation was positively associated with the expression pattern of IbPAL1 in a tissue-specific manner,as further demonstrated by overexpression of IbPAL1.Overexpression of IbPAL1 promoted CGA accumulation and biosynthetic pathway genes expression in leaves,stimulated secondary xylem cell expansion in stems,and inhibited storage root formation.Our results support a potential role for IbPAL1 in sweetpotato CGA biosynthesis and establish a theoretical foundation for detailed mechanism research and nutrient improvement in sweetpotato breeding programs.
基金supported by the National Natural Science Foundation of China (Grant No. 30370830)
文摘Plant temperature （Tp） and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile （TGMS） rice line, Pei＇ai 64S. Significant differences in the daily change of temperature were detected between Tp and air temperature at the height of 150 cm （TA）. From 8：00 to 20：00, Tp was lower than TA, but they were similar during 21：00 to next 7：00. The maximum Tp occurred one hour earlier than the maximum TA, though they both reached the minimum at 6：00. Tp fluctuated less than TA. At the same height, during 6：00-13：00, Tp was higher than air temperature （Ta）, and Tp reached the maximum one hour earlier than Ta. During the rest time on sunny day, Tp was close to or even a little lower than Ta. On overcast day, Tp was higher than Ta in the whole day, and both maximized at the same time. In addition, Tp was regulated by solar radiation, cloudage and wind speed in daytime, and by irrigation water at night. The present study indicated that a TA of 29.6℃ was the critical point, at which Tp was increased or decreased by irrigation water. Tp and the difference between water and air temperatures showed a conic relation. Tp fluctuation was also regulated by the absorption or reflection of solar radiation by leaves during daytime and release of heat energy during nighttime. By analysis on correlation and regression simulation, two models of Tp were established.
基金supported by the National Natural Science Foundation of China(Grant No.30571102)the Key Projects in the National Science & Technology Pillar Program of China(Grant No.2006BAD02A13)the Provincial Natural Science Foundation of Zhejiang(Grant No.Y3100270)
文摘Dissolved oxygen and nitrogen form have important effects on rice root growth and nitrogen availability.An indica hybrid rice,Guodao 1,and a conventional japonica rice,Xiushui 09,were cultured in hypoxic nutrient solution with NH4NO3 or(NH4)2SO4 as the nitrogen source for six weeks in pools.A portion of the Guodao 1 seedlings after treatment in the pools for four weeks were transferred to a split-root system at different dissolved oxygen contents and cultured for an additional two weeks.Biomass,root morphological traits and nitrogen accumulation were recorded.Under the low rhizosphere dissolved oxygen content(0-1.0 mg/L),plant biomass was significantly increased under NH4NO3-N supply by about 69% in Guodao 1 and 41% in Xiushui 09 compared with those under NH4+-N alone.Similar results were observed for root number,maximum root length,root dry weight and root activity.Nitrogen accumulations in roots and shoots were increased by 60% and 52% for Guodao 1,and by 41% and 33% for Xiushui 09,respectively,in the NH4NO3-N treatment.In the split-root system,the high rhizosphere dissolved oxygen content(8.0-9.0 mg/L) promoted root growth and development.Root biomass was increased by 21.6%,root number by 27%,maximum root length by 14%,and root volume by 10%.Moreover,nitrogen accumulation in roots was increased by 11% under high rhizosphere oxygen conditions.In conclusion,enhanced dissolved oxygen content and combined ammonium-nitrate nitrogen source have positive effects on root growth and nitrogen accumulation of rice plants.
基金supported by the National Transgenic Crops Program, China (Grant No. 2008ZX08001-006)the Research Funds for Public Benefit in Ministry of Agriculture, China (Grant No. 200803056)+1 种基金the Key Support Program of Jiangsu Science and Technology, China (Grant No. BE2008354)the Self-directed Innovation Fund of Agricultural Science and Technology in Jiangsu Province, China (Grant No. CX [08]603)
文摘Rice with low glutelin content is suitable as functional food for patients affected by kidney failure. Low glutelincontent gene Lgc1 in rice has a 3.5-kb deletion between two highly similar glutelin genes GluB4 and GluB5, which locates on the short arm of chromosome 2. To improve the selection efficiency in low glutelin-content rice breeding, two molecular markers designated as InDel-Lgc1-1 and InDel-Lgc1-2 were developed to detect the low glutelin-content gene Lgc1. A double PCR detection indicated that combined use of the two markers could easily distinguish the genotypes of Lgc1 from different rice varieties. Therefore, as a simple and low-cost technique, the molecular marker could be widely used to identify different varieties with Lgc1 gene and applied in marker-assisted selection of low glutelin-content rice.
基金supported by the Special Fund of Construction of Modern Agricultural and Industrial Technology System Project (Grant No. CARS-01-47)the Special Fund for Agro-scientific Research in the Public Interest (Grant No. 201503002-5-1)the Key Research & Development Program of Jiangsu Province (Grant No. BE2015363-3) in China
文摘Japonica rice variety Kanto 194 as the donor of resistance gene Stv-b^i and Iow-amylose content gene Wx-mq was used to improve the resistance and eating quality of Wuyujing 3 by the breeding strategy of backcross. In continuous backcross and selfcross generations, the related molecular markers with Stvobi and Wx-mq genes were utilized for genotypic detection by associated with resistance identification of rice stripe disease and agronomic traits selection. Finally, 10 improved lines with homozygous genotype Stv-b^i Stv-b^iWx-mqWx-mq were obtained from BC3F4 generation. The results of comparative analysis indicated that most characters of these lines were consistent with those of recipient parent Wuyujing 3, except for the improved resistance, appearance and eating quality. By evaluation of the comprehensive performance of them, two excellent lines K01 and K04 were selected for further experiments.
基金supported by the National Natural Science Foundation of China (30871459)the Key Project of Cultivate New Varieties of Genetically Modified Technology of China (2008ZX08001-004)+1 种基金the Agricultural Science and Technology Innovation Fundation of Jiangsu Province, China (CX[07]603)the Fundation of Jiangsu Academy of Agricultural Sciences, China (6510707 and 6110704)
文摘In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction （61.7-89.2%） was observed in japonica rice,when cytokinin was added at lower concentration （0.3 mg L-1 6-BA） in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins （2 mg L-1 6-BA,0.5 mg L-1 KT） and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.
基金support by the Ministry of Science and Technology,China (2011CB100403)the Ministry of Agriculture,China (200903035)the Special Project from State Key Laboratory for Biology of Plant Diseases and Insect Pests,Chinese Academy of Agricltural Sciences (SKL2009OP09)
文摘The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.
基金supported by the National Key Technology R&D Program of China (2011BAD16B14, 2012BAD20B05, 2012BAD04B08, and 2013BAD20B05)
文摘Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg.
