燕麦不同组合正、反交杂种后代的表型及遗传参数分析OA北大核心CSTPCD

In order to clarify the phenotypic and genetic variation differences of F1 and backcross hybrid progenies in oat(Avena sativa),crosses were made in this study between four oat varieties:Forage(F709),709(709F),Molass(ML2)and Longyan No.2(L2M).Molecular identification of hybrid F1 plants was conducted by simple sequence repeat(SSR)and their phenotypic differences were compared.The genetic variation and diversity of the F2 generation were also analyzed.It was found that 32 from 37(86.5%)of F1 plants were identified as true hybrids based on SSR.True hybrid rates of up to 88.9%were obtained for the Forage and 709 crosses,and rates of up to 84.2%were obtained for Molass and Longyan No.2.The cross mode significantly affected hybrid phenotype.The flag leaf width of F709-F1 was 19.4%narrower than that of 709F-F1.The grain number of the main panicle of ML2-F1 was 12.2%less than that of L2M-F1.The genetic variation of the F2 population was remarkable.Significant differences were observed in the F2 genetic variation coefficient(Gcv),generalized heritability(Hb)and relative genetic progress(ΔGt)of the same trait in F1 and backcrosses.Among the F2 population,plant height had the lowest Gcv(4.50%-10.27%)and higher Hb(33.12%-85.41%)while tiller number and effective tiller number had the greatest relative genetic progress.The Hb of peduncle length of the F2 population from Forage and 709 was the lowest(14.13%for the F1 cross and 23.81%for the backcross),with the least relative genetic progress.Significant Gcv and Hb differences between the F1 and backcrosses,were observed for grain number of the main panicle with values of 7.09%and 22.54%,respectively in F709-F2,and 19.03%and 66.01%in the backcross.The leaf number of the F2 population from Molass and Longyan No.2 had the highest Hb(99.53%),indicating little environmental effect.The Hb of flag leaf width of ML2-F2 was 9.07%,and ΔGt was 2.79,while in L2M-F2,Hb was 30.23%and ΔGt was 9.77.Ten polymorphic SSR primers resulted in 73.5%polymorphism rate in the F2 population.Actual heterozygosity(0.35-0.99)was much higher than the expected heterozygosity.The Nei's gene polymorphism and Shannon index were 0.29-0.50 and 0.53-0.71,respectively,indicating an obvious segregation and greater variation with great selection potential.