Genetic Study On Late Heading Traits Of Improved Progenies Of Synthetic Wheat

Synthetic wheat contains a variety of hereditary material from donor species,and its effective utilization is an important way to achieve a breakthrough in wheat breeding.The heading date related genes regulate the transformation of plant from vegetative growth to reproductive growth by responding to the length of sunlight.Lengthening the vegetative growth stage,that is,delaying the heading,it can prolong the spikes growth and florets development time.So some unstable florets can completely develop,thereby increasing the fertile spikelets and wheat yield as effective potential way.Excavation and utilization of heading date related genes is great significance for wheat introduction,wheat breeding and expansion of wheat planting area.We used artificially synthesized hexaploid wheat Syn-SAU-24?with late heading?crossing with three bread wheat?with early heading?,and obtained the F₆ generation with good agronomic traits.They show the different heading date.In this study,we used these materials to analyze the reasons of heading date segregation in progeny and breeding evaluation.The main results are as follows:1.Early heading and late heading progenies show stable heading date respectively.Middle heading progenies?between Syn-SAU-24 and bread wheat?naturally formed a population with heading date segregation.The heading date of two isolated populations was investigated,we found early:mid:late=1:2:1(Xc²<X²_0.05,P>0.05),it is controlled by a incomplete dominant genes.2.In different years and different places,there is still a difference in heading date between early and late heading date with stable inheritance.The seed number in late heading plant is obvious advantages than early heading plant.The seed number and spikelets number in late heading date has obvious advantages in Chengdu erea.3.Two pairs of complementary specific markers were developed by using the 7^thh exon sequence of Ppd-D1 gene.By analysis of segregation population,it was found that late heading trait is caused by the Ppd-D1?HapIV type?from common wheat MY1848.Specific markers is accurate and quick,it is also simple to operate and easy to distinguish.It provides a simple and feasible method to identify the HapIV type of Ppd-D1.