ILP Marking Of Hybrid Breeding Genealogy From Indica-Japonice Rice And Genetic Research On Yield-Related Traits

It is an important direction to select applied and preponderant Indica and Japonica subspecies of hybrid rice in this stage of super-high-yield rice breeding.This study used Indica and Japonica subspecies of rice hybrid breeding pedigree involving 20 parents and 30 pro-bred strains lasting 18 years,four breeding stages as research materials.It analyzed the genetic diversity of breeding pedigree by using ILP molecular marker.Based on the results of clustering,seven different times bred strains are elected.Together with four CMS(2 three systems CMS:Guangkang 13B,Ⅱ-32B;2 two systems CMS:guangzhan 63S,peiai 64S)of large area application in the production,according to incomplete double row hybrid design(4×7),they are composed into a set of genetic materials including the pro-generation hybrids and two generations.Genotype and environment interaction increases-dominant genetic model and their statistical analysis are applied.The production-related genetic effects,heterosis and their rice high-production breeding application value of eight characters are analyzed in different ecological conditions(putian and shaxian).The main research findings are as follows:1.ILP molecular marker analysis showed that in 62 pairs of ILP primers,there are 58 pairs of primers to amplify the clear and the same band as the control of 93-11 and Japan Qing.The 58 pairs of primers are amplified to 124 bands.Molecular weight is 250-1500 bp,in which each of the amplification primers were 2-4,with an average of 2.01 bands each.Indica and Japonica characteristics of tested materials can be distinguished significantly by ILP markings.According to ILP marker data clustering results,with similar coefficient 0.67 as threshold,it can separate tested materials into three major groups,namely rice,intermediate and indica.2.The heredity effects and heredity rate analysis on yield trait of variety Indica and Japonice materials in different conditions indicates that except that yield of per plant and burliness rate are not obvious in additive effects,8 yield-related traits investigated are obvious in additive and positive effects.Among them,available spike number per plant and main spike total grain number and 1000-grain weight are additive effects.Plant height, main spike length,solid grain number of main spike,burliness rate and yield of per plant are positive effects.8 yield-related traits investigated are obviously additive,positive and environment interaction effects.All of them are main positive and environment interaction effects.General narrow sense heredity rate order is main spike total grain number＞1000-grain weight＞available spike number per plant＞main spike length＞plant height＞burliness rate＞yield of per plant.All of them are affected by genotype and environment interaction effects.3.The heredity effects analysis on yield-related traits of varieties bred in different conditions indicates that 92gk729,97gk419 have extremely obvious additive effects to raise offspring's height.;97gk1037 has obvious effects to reduce offspring's height;Minghui 502,Minghui 413 have extremely obvious additive effects to raise offspring's grain number on the base of main spike length main spike total grain number and main spike solid grain number.The crossbreed offspring are easy to be big spike and high production.Based on solid spike number,92gk729,97gk419,Minghui502,Minghui 413 have obviously negative effects to reduce the spike number.Based on burliness rate,except 92gk1019 and Minghui 417,the rest have obviously positive effects to increase the burliness rate.Based on yield of per plant,offspring are easy to be affected by environment but additive effects.Based on 1000-grain weight,92gk419,97gk1037,Minghui417 are positive but Peiai 64S,92gk729,Minghui502,Minghui 413 are negative. Minghui 502 and Minghui 413 reflect the same direction to increase or reduce effects,which means,in different conditions,these two varieties are steady not easy to be affected by environment.97gk419,97gk1037 and 97gk1019 have very different environment interaction prediction value of yield-related traits.They are easy to be affected by the change of environment.So these three varieties are notfight suitable to be the parents for yield-related trait improvement.4.The analysis on the heterosis of yield-related traits of Indica and Japonica hybrid rice varieties bred under different environments showed that yield-related traits are affected by genetic×environment interaction effects.Except that for effective panicles per plant and burliness rate performance-based value of eight yield-related traits investigated is bigger than genotypes value.The rest order is spike total grains＞panicle grains＞plant yield＞1000-grain weight＞plant height＞spike length.Among them plant height,spike total grains,burliness rate,plant yield and 1000-grain weight reached a significant or extremely significant level.Plant height,burliness rate and 1000-grain weight showed significant positive group average potential in eight traits investigated except effective panicles,which means these 3 traits only reflect difference in the level of colony average potential.The main spike grains,the main spike total grains and per plant yield in different environments showed significant different direction in interaction effects,reaching obvious level,which means these 2 traits have bad stability of colony average potential.The interaction effects of effective panicles and burliness rate are negative in two environments with negative colony exceeding-parent superiority.But under bad environment,colony exceeding-parent superiority is stronger.The colony exceeding-parent superiorit of main spike grains,the main spike total grains,per plant yield and 1000-grain weight is bad in stability.Under bad environment,negative colony exceeding-parent superiority is stronger,with more obvious performance of main spike solid grains.