Evaluation And Utilization Of Rice Breeding Resources

Long-term breeding practice shows that the major breakthrough in rice breeding is based on the discovery of excellent rice germplasm resources and the creation of new breeding resources materials.Therefore,strengthening the evaluation and utilization of rice breeding resources will help to explore more valuable resources and shorten the breeding process of new hybrid rice combinations.In this study,the yield and yield components of nearly 800 rice breeding materials were investigated,and the degree of indica and japonica was determined by Cheng’s index method.Among them,180 materials were identified by InDel molecular marker method.On this basis,16 strain materials were selected to mate with three-line male sterile lines(Chuan106A,GuangheA,Guang8 A,Jing3A,65A)respectively,and their heterosis performance was analyzed comprehensively.The results are as follows:The results of agronomic traits identification showed that there were 6 multi-grain breeding resources with total grains of more than 250 grains per panicle,5 with grains of more than 200 grains of real seed per panicle,39 with seed setting rate of over 90%,107 multi-panicle breeding resources with effective panicles of more than 20 panicles per plant,16 large-grain breeding resources with 1000-grain weight of more than 30 grams,and 60 breeding materials with grain yield of more than 50 grams per plant.The results of indica-japonica degree discrimination by Cheng’s index method showed that 751 materials could be divided into four types: japonica type,japonicaclinos type,indicaclinous type and indica type.There were 638 indica materials,73 indicaclinous materials,34 japonicaclinous materials and 6 japonica materials.In the correlation analysis of six indica-japonica classification traits,only grain length-width ration was negatively correlated with leaf hairs,while other indica-japonica classification traits showed significant or extremely significant positive correlation.According to the analysis,Cheng’s index method could be used to discriminate indica-japonica attributes more accurately.The results of indica-japonica degree identification by InDel method showed that among 180 InDel molecular test materials,six types were classified,including 88 typical indica rice,66 indica rice,13 indicaclinous rice,9 intermediate type,2 japonicaclinous rice and 2 typical japonica rice.By comparing InDel with Cheng~,s index method,the coincidence degree of indica and japonica attributes between them is 90.5%,this shows that the two methods can be used to classify the indica and japonica properties of typical indica and japonica materials to achieve complete consistency.Moreover,the Cheng~,s index of indica and japonica attributes was extremely significant positive correlated with the frequency of the InDel japonica genotype.It also showed that InDel molecular markers could be used to determine the degree of indica and japonica.The results of heterosis analysis of 80 hybrid combinations showed that:judging from the test combinations exceed parent advantages,except the effective panicle per plant,the average over-paternal heterosis of the other six traits was positive,which mainly manifested in the increase of panicle length,total grain per panicle and grain per panicle,and the increase of actual yield per plant.Among the over standard heterosis,among the seven traits,only panicle length,total grains per panicle and effective panicles per plant showed positive dominace,and the mean value of over-standard advantage was 1.14%,5.92%and 28.36%,respectively.Among them,the average yield per plant of 17 Zhong165,17 Zhong314 are matched series combinations showed forward direction over-standard heterosis.Therefore,it is conditional to select strong combinations with traits more than Fengliangyou 4 from the tested combinations.The results of correlation analysis showed that the distance of InDel markers between parents and the difference value of Cheng~,s index between parents were markedly positive correlated with the super-paternal advantage of total grain traits per panicle.The distance of InDel markers was positively correlated with the super-paternal advantage of panicle length,filled grain numbers per panicle,seed setting rate and grain yield per plant,negatively correlated with the super-paternal heterosis of effective panicle per plant and 1000-grain weight traits,but the correlation is not significant;and the difference of Cheng~,s index between parents was significantly positive correlated with the super-paternal advantages of effective panicle per plant and grain yield per plant,but the correlation between the difference of Cheng~,s index between parents and the super-paternal heterosis performance of several other traits was also less marked.Among the advantages of exceeding the standard,the difference of InDel mark distances and Cheng~,s index between parents were significantly positive correlated with the over-standard advantage of effective panicle traits per plant.However,InDel mark distances and Cheng~,s index differences between parents were non-significant positively correlated with the excessive standard advantages of filled grain numbers per panicle,seed setting rate and grain yield per plant.InDel mark distances between parents and Cheng~,s index differences between parents were non-significant negatively correlated with the over-standard advantage of total grain numbers per panicle.Among them,InDel mark distances between parents was positively correlated with the over-standard advantage of spike length and negatively correlated with the over-standard heterosis of 1000-grain weight,but the correlation was not significant,and the difference of Cheng~,s index between parents was also not significantly correlated with it.