In order to clarify the transmission of the rye chromosome 1R in winter wheat germplasm Aimengniu and its derivatives, 17 derivatives and 7 types of Aimengniu were examined through molecular-marker technology. The res...In order to clarify the transmission of the rye chromosome 1R in winter wheat germplasm Aimengniu and its derivatives, 17 derivatives and 7 types of Aimengniu were examined through molecular-marker technology. The results showed that the chromosome arm 1RS of Neuzucht was transmitted to 5 of the 7 types of Aimengniu, i.e., Aimengniu Ⅱ and Aimengniu Ⅳ-Aimengniu VII, no segment of t RS was identified in Aimengniu Ⅰ or Aimengniu Ⅲ. As for the 17 derivatives, the 1RS chromosome arm of Aimengniu was transmitted to 11 derivatives, part segments of 1RS were found in 1 derivative, while no segment was found in the remaining 5 ones. The results provided the evidence that molecular-marker technology was an efficient approach and suitable for analysis of the transmission of chromosome 1R.展开更多
Bread wheat provides an essential fraction of the daily calorific intake for humanity.Due to its huge and complex genome,progress in studying on the wheat genome is substantially trailed behind those of the other two ...Bread wheat provides an essential fraction of the daily calorific intake for humanity.Due to its huge and complex genome,progress in studying on the wheat genome is substantially trailed behind those of the other two major crops,rice and maize,for at least a decade.With rapid advances in genome assembling and reduced cost of high-throughput sequencing,emerging de novo genome assemblies of wheat and whole-genome sequencing data are leading to a paradigm shift in wheat research.Here,we review recent progress in dissecting the complex genome and germplasm evolution of wheat since the release of the first high-quality wheat genome.New insights have been gained in the evolution of wheat germplasm during domestication and modern breeding progress,genomic variations at multiple scales contributing to the diversity of wheat germplasm,and complex transcriptional and epigenetic regulations of functional genes in polyploid wheat.Genomics databases and bioinformatics tools meeting the urgent needs of wheat ge-nomics research are also summarized.The ever-increasing omics data,along with advanced tools and well-structured databases,are expected to accelerate deciphering the germplasm and gene resources in wheat for future breeding advances.展开更多
Grain number per spike （GNPS） is a major factor in wheat yield breeding. A new wheat germplasm Pubing 3504 shows superior features in spike traits. To elucidate the genetic basis of spike and yield related traits in...Grain number per spike （GNPS） is a major factor in wheat yield breeding. A new wheat germplasm Pubing 3504 shows superior features in spike traits. To elucidate the genetic basis of spike and yield related traits in Pubing 3504, 282 F2：3 families were generated from the cross Pubing 3504xJing 4839, and seven spike and yield related traits, including GNPS, spike length （SL）, kernel number per spikelet （KPS）, spikelet number per spike （SNS）, thousand-grain weight （TGW）, spike number per plant （SNP）, and plant height （HT） were investigated. Correlation analysis indicated significant positive correlations between GNPS and spike-related traits, including KPS, SNS, and SL, especially KPS. A genetic map was constructed using 190 polymorphic simple sequence repeat （SSR）, expressed sequence tag （EST）-SSR, and sequence- tagged-site （STS） markers. For the seven traits measured, a total of 37 quantitative trait loci （QTLs） in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected. Additive effects of 70.3% （in a single environment） and 57.6% （in a joint environment） of the QTLs were positively contributed by Pubing 3504 alleles. Five important genomic regions on chromosomes 1A, 4A, 4B, 2D, and 4D could be stably detected in different environments. Among these regions, the marker interval Xmag834-Xbarc83 on the short arm of chromosome 1A was a novel important genomic region that included QTLs controlling GNPS, KPS, SNS, TGW, and SNP with stable environmental repeatability. This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future. We deduced that this genomic region was vital to the high GNPS of Pubing 3504.展开更多
Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses. Of the biotic stresses a devastating pest (Russian wheat aphid (RWA)) and a serious ...Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses. Of the biotic stresses a devastating pest (Russian wheat aphid (RWA)) and a serious disease (stem rust race TTKS (“Ug99”)) are currently the biggest problem for wheat producers in Kenya. Severe infestations by RWA may result in yield losses of up to 90% while “Ug99” infected fields may suffer 100% crop loss. The two pests combined are seriously affecting wheat farmers’ incomes because of the heavy reliance on pesticides that increase the cost of production. This study attempted to develop and characterize wheat lines that are resistant to both RWA and “Ug99” by pyramiding two major resistance genes. Three wheat varieties: “Kwale”, a Kenyan high yielding variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line with resistance to RWA but of poor agronomic attributes were used. A double cross F1 (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99” resistance. Surviving DC F1 progenies were left to self pollinate to obtain the F2 of the double cross (DC F2). The DC F2 progenies were sequentially screened against RWA and “Ug99” to yield a population that was resistant to both RWA and “Ug99”. Genotyping of the DC F2:3 families were conducted to select homozygous resistant plants. Data indicated that the RWA and “Ug99” resistance genes were successfully pyramided. Though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99” and can still be effectively used as a component for “Ug99” resistance breeding together with other Sr genes.展开更多
Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f.sp.tritici,which could limit yields.Thus development and cultivation of genetically ...Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f.sp.tritici,which could limit yields.Thus development and cultivation of genetically diverse and resistant varieties is the most sustainable solution to overcome these diseases.The first objective of the present study was to evaluate 100 Pakistan wheat cultivars that have been grown over the past 60 years.These cultivars were inoculated at the seedling stage with two virulent stripe rust isolates from the United States and two from Pakistan.None of the wheat cultivars were resistant to all tested stripe rust isolates,and 16% of cultivars were susceptible to the four isolates at the seedling stage.The data indicated that none of the Pakistan wheat cultivars contained either Yr5 or Yr15 genes that were considered to be effective against most P.striiformis f.sp.tritici isolates from around the world.Several Pakistan wheat cultivars may have gene Yr10,which is effective against isolate PST-127 but ineffective against PST-116.It is also possible that these cultivars may have other previously unidentified genes or gene combinations.The second objective was to evaluate the 100 Pakistan wheat cultivars for stripe rust resistance during natural epidemics in Pakistan and Washington State,USA.It was found that a higher frequency of resistance was present under field conditions compared with greenhouse conditions.Thirty genotypes (30% of germplasms) were found to have a potentially high temperature adult plant (HTAP) resistance.The third objective was to determine the genetic diversity in Pakistan wheat germplasms using molecular markers.This study was based on DNA fingerprinting using resistance gene analog polymorphism (RGAP) marker analysis.The highest polymorphism detected with RGAP primer pairs was 40%,50% and 57% with a mean polymorphism of 36%.A total of 22 RGAP markers were obtained in this study.RGAP,simple sequence repeat (SSR) and sequence tagged site (STS) markers were used to determine the presence and absence of some important stripe rust resistance genes,such as Yr5,Yr8,Yr9,Yr15 and Yr18.Of the 60 cultivars analyzed,17% of cultivars showed a RGAP marker band for Yr9 and 12% of cultivars exhibited the Yr18 marker band.No marker band was detected for Yr5,Yr8 and Yr15,indicating a likely absence of these genes in the tested Pakistan wheat cultivars.Cluster analysis based on molecular and stripe rust reaction data is useful in identifying considerable genetic diversity among Pakistan wheat cultivars.The resistant germplasms identified with 22 RGAP markers and from the resistance evaluations should be useful in developing new wheat cultivars with stripe rust resistance.展开更多
Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers...Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.展开更多
The composition of high molecular weight glutenin subunits( HMW-GS) was analyzed using SDS-PAGE with 70 Longdong dryland winter wheat germplasm resources as experimental materials.The results showed that Longdong dryl...The composition of high molecular weight glutenin subunits( HMW-GS) was analyzed using SDS-PAGE with 70 Longdong dryland winter wheat germplasm resources as experimental materials.The results showed that Longdong dryland winter wheat germplasm resources had N,7 + 8,2 + 12 as the dominant HMW-GS composition( 42.86%),while the dominant HMW-GS composition in the introduced germplasms was N,7 + 9,2 + 12( 36.84%).On the Glu-B1 locus of Longdong dryland germplasms,subunit 7 + 8 had the highest frequency,accounting for 65.71%,and on the Glu-B1 locus of the introduced germplasms,subunit7 + 9 had the highest frequency,accounting for 57.89%.Whether subunit 7 + 8 is related to drought resistance in varieties still needs further study.On Glu-D1 locus,high-quality subunit 5 + 10 appeared in the introduced resources for 5 times,accounting for 13.16% of all the introduced lines,and appeared in Longdong dryland winter wheat germplasm resources for 2 times,only accounting for 2.86% of all the resources,suggesting that Longdong dryland germplasms lack high-quality subunits and need further improvement.展开更多
基金supported by the National Basic Research Program of China (973 Program,2006CB101700)
文摘In order to clarify the transmission of the rye chromosome 1R in winter wheat germplasm Aimengniu and its derivatives, 17 derivatives and 7 types of Aimengniu were examined through molecular-marker technology. The results showed that the chromosome arm 1RS of Neuzucht was transmitted to 5 of the 7 types of Aimengniu, i.e., Aimengniu Ⅱ and Aimengniu Ⅳ-Aimengniu VII, no segment of t RS was identified in Aimengniu Ⅰ or Aimengniu Ⅲ. As for the 17 derivatives, the 1RS chromosome arm of Aimengniu was transmitted to 11 derivatives, part segments of 1RS were found in 1 derivative, while no segment was found in the remaining 5 ones. The results provided the evidence that molecular-marker technology was an efficient approach and suitable for analysis of the transmission of chromosome 1R.
基金supported by the National Natural Science Foundation of China(32272124,31991210)and the 2115 Talent Development Program.
文摘Bread wheat provides an essential fraction of the daily calorific intake for humanity.Due to its huge and complex genome,progress in studying on the wheat genome is substantially trailed behind those of the other two major crops,rice and maize,for at least a decade.With rapid advances in genome assembling and reduced cost of high-throughput sequencing,emerging de novo genome assemblies of wheat and whole-genome sequencing data are leading to a paradigm shift in wheat research.Here,we review recent progress in dissecting the complex genome and germplasm evolution of wheat since the release of the first high-quality wheat genome.New insights have been gained in the evolution of wheat germplasm during domestication and modern breeding progress,genomic variations at multiple scales contributing to the diversity of wheat germplasm,and complex transcriptional and epigenetic regulations of functional genes in polyploid wheat.Genomics databases and bioinformatics tools meeting the urgent needs of wheat ge-nomics research are also summarized.The ever-increasing omics data,along with advanced tools and well-structured databases,are expected to accelerate deciphering the germplasm and gene resources in wheat for future breeding advances.
基金supported by grants from the National Basic Research Program of China(973 Program,2011CB100104)the National High-Tech R&D Program of China(2011AA100101)+2 种基金the National Natural Science Foundation of China(31071416)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2013BAD01B02)
文摘Grain number per spike （GNPS） is a major factor in wheat yield breeding. A new wheat germplasm Pubing 3504 shows superior features in spike traits. To elucidate the genetic basis of spike and yield related traits in Pubing 3504, 282 F2：3 families were generated from the cross Pubing 3504xJing 4839, and seven spike and yield related traits, including GNPS, spike length （SL）, kernel number per spikelet （KPS）, spikelet number per spike （SNS）, thousand-grain weight （TGW）, spike number per plant （SNP）, and plant height （HT） were investigated. Correlation analysis indicated significant positive correlations between GNPS and spike-related traits, including KPS, SNS, and SL, especially KPS. A genetic map was constructed using 190 polymorphic simple sequence repeat （SSR）, expressed sequence tag （EST）-SSR, and sequence- tagged-site （STS） markers. For the seven traits measured, a total of 37 quantitative trait loci （QTLs） in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected. Additive effects of 70.3% （in a single environment） and 57.6% （in a joint environment） of the QTLs were positively contributed by Pubing 3504 alleles. Five important genomic regions on chromosomes 1A, 4A, 4B, 2D, and 4D could be stably detected in different environments. Among these regions, the marker interval Xmag834-Xbarc83 on the short arm of chromosome 1A was a novel important genomic region that included QTLs controlling GNPS, KPS, SNS, TGW, and SNP with stable environmental repeatability. This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future. We deduced that this genomic region was vital to the high GNPS of Pubing 3504.
文摘Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses. Of the biotic stresses a devastating pest (Russian wheat aphid (RWA)) and a serious disease (stem rust race TTKS (“Ug99”)) are currently the biggest problem for wheat producers in Kenya. Severe infestations by RWA may result in yield losses of up to 90% while “Ug99” infected fields may suffer 100% crop loss. The two pests combined are seriously affecting wheat farmers’ incomes because of the heavy reliance on pesticides that increase the cost of production. This study attempted to develop and characterize wheat lines that are resistant to both RWA and “Ug99” by pyramiding two major resistance genes. Three wheat varieties: “Kwale”, a Kenyan high yielding variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line with resistance to RWA but of poor agronomic attributes were used. A double cross F1 (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99” resistance. Surviving DC F1 progenies were left to self pollinate to obtain the F2 of the double cross (DC F2). The DC F2 progenies were sequentially screened against RWA and “Ug99” to yield a population that was resistant to both RWA and “Ug99”. Genotyping of the DC F2:3 families were conducted to select homozygous resistant plants. Data indicated that the RWA and “Ug99” resistance genes were successfully pyramided. Though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99” and can still be effectively used as a component for “Ug99” resistance breeding together with other Sr genes.
基金supported by the financial from the Higher Education Commission Pakistan,through the Pak-US research initiative (Grant No. 2-108/HEC/2006)
文摘Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f.sp.tritici,which could limit yields.Thus development and cultivation of genetically diverse and resistant varieties is the most sustainable solution to overcome these diseases.The first objective of the present study was to evaluate 100 Pakistan wheat cultivars that have been grown over the past 60 years.These cultivars were inoculated at the seedling stage with two virulent stripe rust isolates from the United States and two from Pakistan.None of the wheat cultivars were resistant to all tested stripe rust isolates,and 16% of cultivars were susceptible to the four isolates at the seedling stage.The data indicated that none of the Pakistan wheat cultivars contained either Yr5 or Yr15 genes that were considered to be effective against most P.striiformis f.sp.tritici isolates from around the world.Several Pakistan wheat cultivars may have gene Yr10,which is effective against isolate PST-127 but ineffective against PST-116.It is also possible that these cultivars may have other previously unidentified genes or gene combinations.The second objective was to evaluate the 100 Pakistan wheat cultivars for stripe rust resistance during natural epidemics in Pakistan and Washington State,USA.It was found that a higher frequency of resistance was present under field conditions compared with greenhouse conditions.Thirty genotypes (30% of germplasms) were found to have a potentially high temperature adult plant (HTAP) resistance.The third objective was to determine the genetic diversity in Pakistan wheat germplasms using molecular markers.This study was based on DNA fingerprinting using resistance gene analog polymorphism (RGAP) marker analysis.The highest polymorphism detected with RGAP primer pairs was 40%,50% and 57% with a mean polymorphism of 36%.A total of 22 RGAP markers were obtained in this study.RGAP,simple sequence repeat (SSR) and sequence tagged site (STS) markers were used to determine the presence and absence of some important stripe rust resistance genes,such as Yr5,Yr8,Yr9,Yr15 and Yr18.Of the 60 cultivars analyzed,17% of cultivars showed a RGAP marker band for Yr9 and 12% of cultivars exhibited the Yr18 marker band.No marker band was detected for Yr5,Yr8 and Yr15,indicating a likely absence of these genes in the tested Pakistan wheat cultivars.Cluster analysis based on molecular and stripe rust reaction data is useful in identifying considerable genetic diversity among Pakistan wheat cultivars.The resistant germplasms identified with 22 RGAP markers and from the resistance evaluations should be useful in developing new wheat cultivars with stripe rust resistance.
文摘Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yandal817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157, Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.
基金Supported by the Gansu Dryland Winter Wheat Germplasm Innovation and Application Engineering Research Center
文摘The composition of high molecular weight glutenin subunits( HMW-GS) was analyzed using SDS-PAGE with 70 Longdong dryland winter wheat germplasm resources as experimental materials.The results showed that Longdong dryland winter wheat germplasm resources had N,7 + 8,2 + 12 as the dominant HMW-GS composition( 42.86%),while the dominant HMW-GS composition in the introduced germplasms was N,7 + 9,2 + 12( 36.84%).On the Glu-B1 locus of Longdong dryland germplasms,subunit 7 + 8 had the highest frequency,accounting for 65.71%,and on the Glu-B1 locus of the introduced germplasms,subunit7 + 9 had the highest frequency,accounting for 57.89%.Whether subunit 7 + 8 is related to drought resistance in varieties still needs further study.On Glu-D1 locus,high-quality subunit 5 + 10 appeared in the introduced resources for 5 times,accounting for 13.16% of all the introduced lines,and appeared in Longdong dryland winter wheat germplasm resources for 2 times,only accounting for 2.86% of all the resources,suggesting that Longdong dryland germplasms lack high-quality subunits and need further improvement.
