Genetic Analysis And Evaluation Of Late Heading Trait In Improved Lines Of Synthetic Wheat

The time of heading and flowering influences the final yield.O ne of the important genetic bases of rice heterosis for yield traits is the regulation of heading and flowering time.When considering both yield and timing,the heterozygous genotype only slightly delayed flowering increase grain yield.In improved strains derived from synthetic wheat Syn-SAU-24/MY1848//Y3///CM42,we found that:the strains have homozygous Ppd-D1^MY1848 show obvious late heading;the strains have homozygous Ppd-D1^CM42show early heading;heterozygous Ppd-D1 genotype show Middle heading.But synthetic wheat Syn-SAU-24 is obvious late heading,common wheats（MY1848,Y3 and CM42）are early heading.We found that heading time is controlled by a incomplete dominant genes and Ppd-D1 is the reason.Therefore,there is a gene which can interact with Ppd-D1.Ppd-D1^MY1848and its interacting gene maybe key genes in wheat breeding.In this study,we analyzed the interacting gene and its breeding evaluation,and analyzed the expression of related genes in photoperiod pathway.The main results are as follows:1.The interacting gene with Ppd-D1^MY1848 is a recessive gene in nucleus by populations.2.Heading dates of F₁ plants derived from late heading strains and common wheats divide to 3 groups.F₁ plants derived from late heading strains and 15 common wheats have slightly delayed heading than common wheat parent.Parts of F₁ have well agronomic traits and breeding value.3.By analysis of 55K chip,early heading strains and late heading strains have 6.54%and 7.21%genetic materials from Syn-SAU-24 respectively.Late heading strains have Ppd-D1^MY1848 indeed.4.The expression patterns of the major photoperiod genes Ta GI、Ta TOC、Ppd、Ta PRR73、Ta CDF、Ta CO-2 and Ta FT showed circadian rhythm.The highest expression occurs under light condition,and the expression decreased under dark condition.