Composition and Distribution of Wheat Photoperiod Genes in Different Wheat Regions in China
In order to identify the distribution characteristics of the allelic composition of photoperiod genesPpd-A1,Ppd-B1 and Ppd-D1 in Chinese wheat cultivars,the photoperiod genes of 977 Chinese wheat cultivars in this study were identified using the molecular markers,and the differences on the composition of photoperiodic genotype in different wheat regions were analyzed and compared.The results showed that five cultivars(0.5%) have no PCR amplication at Ppd-A1 locus,and the remaining 972(99.5%) cultivars carry photoperiod sensitive allele Ppd-A1b.At Ppd-B1 locus,only cultivar Qingchun 37(0.1 %) carries photoperiod insensitive allele Ppd-B1a,and three(0.3 %00) cultivars have no PCR amplification,and the remaining 973 (99.6%) cultivars carry photoperiod sensitive allele Ppd-B1b.AtPpd-D1 locus,789 (80.8%) cultivars have photoperiod insensitive allelePpd-D1a and the remaining 188(19.2%) cultivars carry photoperiod sensitive allelePpd-D1b.At high latitude regions,such as Northeast Spring Wheat Region,Xinjiang Winter-Spring Region and Qinghai-Tibet SpringWinter Region,most of the cultivars carry photoperiod sensitive allele Ppd D1b,but insensitive allele Ppd-D1a had higher frequency distribution in Northern Winter Wheat Region,Yellow and Huai River Winter Wheat Region,and Middle and Lower Reaches of Yangtze Valley Winter Wheat Region.In general,the frequency of PpdD1a in Yellow and Huai River Winter Wheat Region was the highest and there is a downward trend in other wheat regions.The variation types with no PCR amplification were found at PpdA1 locus or Ppd-B1 locus.Those variation cultivars would enrich the diversity of wheat breeding germplasm resources,and lay the material foundation for the selection of varieties to adapt to different environmental conditions and could be used as important experimental materials for further research.