Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed...Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed using a set of 139 simple sequence repeat（SSR） markers in 130 hexaploid wheat varieties and 193 Aegilops tauschii accessions worldwide. In total, 1 612 alleles in Ae. tauschii and 1 360 alleles in hexaploid wheat（Triticum aestivum L.） were detected throughout the D genome. 197 marker-trait associations in Ae. tauschii were identified with 58 different SSR loci in 3 environments, and the average phenotypic variation value（R2） ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identified in wheat with 66 different SSR markers in 4 environments and the average phenotypic R2 ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in both Ae. tauschii and hexaploid wheat, which are significantly associated with the 5 investigated grain traits（i.e., GA, GP, GR, GL, and TGW） and in total, 16 alleles derived from the 6 aforementioned SSR loci were shared by Ae. tauschii and hexaploid wheat. These preliminary data suggest the existence of common alleles may explain the evolutionary process and the selection between Ae. tauschii and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process from Ae. tauschii to hexaploid wheat.展开更多
To lower the amylose content （AC） of the indica rice restorer line 057 with high AC, backcrosses were made respectively by using four indica varieties （R367, 91499, Yanhui 559, Hui 527） as low AC donor parents and...To lower the amylose content （AC） of the indica rice restorer line 057 with high AC, backcrosses were made respectively by using four indica varieties （R367, 91499, Yanhui 559, Hui 527） as low AC donor parents and 057 as the recurrent parent. A molecular marker （PCR-Acc Ⅰ） was used to identify the genotypes （GG, TT and GT） of the waxy （Wx） gene. Plants with GT genotype were selected and used as female parent and crossed with 057 to advance generation. The ACs of rice grains harvested from plants with different Wx genotypes were measured and compared to analyze the efficiency of marker-assisted selection. The ACs of the rice grain, harvested from the plants of Wx genotypes GG, GT and TT, were higher than 20%, in the range of 17.7-28.5%, and less than 18%, respectively. The PCR-Acc Ⅰ marker could be used for efficiently lowering the AC of 057 through backcrossing, and there were some influence of parental genetic background on the AC of rice grains with the same Wx genotype.展开更多
Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions wer...Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions were genotypically characterized, and their physical grain and cooking quality traits were studied. We used specific gene markers associated with aroma, apparent amylose content （AAC） and alkali spreading value to determine the alleles carried by different PSM accessions. The results revealed that six PSM accessions （PSM10, PSM12, PSM13, PSM21, PSM22 and PSM30） had a 3-bp insertion in Os2AP gene. Gel consistency （GC） allele was predominant among the PSM accessions for gelatinization temperature （GT）, however, the phenotype observed was between low and intermediate GT because of the combination of the GC allele with the presence of low GT allele at heterozygous state from the other loci of the SSIla gene. Intermediate to high AAC was observed among the PSM accessions corresponding to the haplotype identified for the single nucleotide polymorphism G/T and the （Cm）n repeat in the Wx gene. The characterization and grouping data of PSM accessions posted benefits to Myanmar seed banks, and our results will help in maintaining the integrity of PSM rice variety.展开更多
基金financial supports by the National 973 Program of China (2014CB138100)the National Natural Science Foundation of China (31171553, 31471488 and 31200982)the National High-Tech R&D Program of China (2011AA100102)
文摘Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed using a set of 139 simple sequence repeat（SSR） markers in 130 hexaploid wheat varieties and 193 Aegilops tauschii accessions worldwide. In total, 1 612 alleles in Ae. tauschii and 1 360 alleles in hexaploid wheat（Triticum aestivum L.） were detected throughout the D genome. 197 marker-trait associations in Ae. tauschii were identified with 58 different SSR loci in 3 environments, and the average phenotypic variation value（R2） ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identified in wheat with 66 different SSR markers in 4 environments and the average phenotypic R2 ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in both Ae. tauschii and hexaploid wheat, which are significantly associated with the 5 investigated grain traits（i.e., GA, GP, GR, GL, and TGW） and in total, 16 alleles derived from the 6 aforementioned SSR loci were shared by Ae. tauschii and hexaploid wheat. These preliminary data suggest the existence of common alleles may explain the evolutionary process and the selection between Ae. tauschii and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process from Ae. tauschii to hexaploid wheat.
文摘To lower the amylose content （AC） of the indica rice restorer line 057 with high AC, backcrosses were made respectively by using four indica varieties （R367, 91499, Yanhui 559, Hui 527） as low AC donor parents and 057 as the recurrent parent. A molecular marker （PCR-Acc Ⅰ） was used to identify the genotypes （GG, TT and GT） of the waxy （Wx） gene. Plants with GT genotype were selected and used as female parent and crossed with 057 to advance generation. The ACs of rice grains harvested from plants with different Wx genotypes were measured and compared to analyze the efficiency of marker-assisted selection. The ACs of the rice grain, harvested from the plants of Wx genotypes GG, GT and TT, were higher than 20%, in the range of 17.7-28.5%, and less than 18%, respectively. The PCR-Acc Ⅰ marker could be used for efficiently lowering the AC of 057 through backcrossing, and there were some influence of parental genetic background on the AC of rice grains with the same Wx genotype.
基金supported by the National Center for Genetic Engineering and Biotechnology,Thailand (Grant No.P1020028)Generation Challenge Program,Mexico (Grant No.P0900835)
文摘Paw San Hmwe （PSM） rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions were genotypically characterized, and their physical grain and cooking quality traits were studied. We used specific gene markers associated with aroma, apparent amylose content （AAC） and alkali spreading value to determine the alleles carried by different PSM accessions. The results revealed that six PSM accessions （PSM10, PSM12, PSM13, PSM21, PSM22 and PSM30） had a 3-bp insertion in Os2AP gene. Gel consistency （GC） allele was predominant among the PSM accessions for gelatinization temperature （GT）, however, the phenotype observed was between low and intermediate GT because of the combination of the GC allele with the presence of low GT allele at heterozygous state from the other loci of the SSIla gene. Intermediate to high AAC was observed among the PSM accessions corresponding to the haplotype identified for the single nucleotide polymorphism G/T and the （Cm）n repeat in the Wx gene. The characterization and grouping data of PSM accessions posted benefits to Myanmar seed banks, and our results will help in maintaining the integrity of PSM rice variety.
