| Identification of distribution of dwarf genes and their influence on agronomic traits in bread wheat could contribute to reasonable use of dwarf genes and could provid evaluable information for wheat breeding program. Different molecular markers at six Rht loci ( Rht1, Rht2, Rht4, Rht8, Rht9 and Rht12) were used to detect distribution of dwarf genes in 246 common wheat from the Yellow and Huai wheat region.A total of ten agronomic traits,including plant height,spike length,peduncle length,spikelet number per spike,flag leaf length,flag leaf width,kernel number per spike,kernel length,kernel width and thousand-kernel weight were investigated for three years and their relationship with the Rht loci were analyzed. The results showed that six dwarf genes showed an extensive distribution in the Yellow and Huai wheat region,especially for the Rht1 and Rht2 genes. Association analysis of the six dwarf genes with the ten agronomic traits in bread wheat showed that at Rht1 locus cultivars with Rht1-B1a and Rht1-B1b alleles did not show significant difference for plant height. At Rht2 locus,cultivars with Rht2-D1b had significantly lower plant height,peduncle length but higher thousand-kernel weight in the three years,suggesting that Rht2-D1b is the superior allele. Excluding the effect of Rht1 and Rht2 genes,due to their strong influence on agronomic traits,the four loci of Rht4, Rht8, Rht9 and Rht12 had also important effects on different agronomic traits in wheat cultivars from the Yellow and Huai valley. Among the four loci, Rht4 played an important role in plant height and thousand-kernel weight and thus Rht4-B1b is the relatively superior allele; Rht8 had important effects on spike length,peduncle length and thousand-kernel weight and thus Rht8-D1b is the relatively superior allele; Rht9 had important effects on plant height and thousand-kernel weight and thus Rht9-A1a is the relatively superior allele; Rht12 had important effects on spike length and thousand-kernel weight and thus Rht12-A1a is the superior allele. Further analysis showed that Rht2 showed the most important effect on plant height among the six loci,which was followed by Rht4. Four ( Rht1, Rht2, Rht8 and Rht12) of the six loci showed significant effect on thousand-kernel weight,of which Rht2 also showed the most significant effect.Analysis of the distribution of the six superior alleles in cultivars from different periods indicated percentage of the superior alleles generally increased from early historical cultivars,recent historical cultivars to modern cultivars in the Yellow and Huai valley,and especially 82.9% of modern cultivars had Rht2-D1b. |
基本信息
