Studies On The Hoterosis And Combining Ability Of Lodging Resistance Raits

With the material of 12 rice sterile lines(5 CMS lines and 7 NMS lines) and 10 restorer lines,the experiment was carried out in non-complete both columns cross, and then tested lodging resistance trait.The heterosis,combination ability and correction were analyzed.The results are as follows.1.Through the heterosis analysis of lodging resistance traits,the results indicated that:plant height,the first and third basal internode's length,long spindle,short spindle,basal internode's thickness have positive mid-heterosis;and plant height,the third basal internode's length,long spindle and short spindle have super-parent heterosis;the first and second basal intemode's length,basal internode's thickness have negative super-parent heterosis,and the first basal internode's length,basal internode's thickness are to lean on the high parent,the second internode's length is to lean on the low parent.2.The parents were evaluated according to the GCA and variance of SCA of lodging index and yield.Among the sterile lines,the performances of Annong 9054S and XieqingzaoA are good.XieqingzaoA's GCA is low,but its variance of SCA of lodging index are high,it's likely to get the right combination,which both lodging resistance and yield are high.Among the restorer lines,R9019 and Minghui86 are good,their GCA and variance of SCA are high,so it's easy to get high lodging resistance and yield combination.In rice breeding,we should select suitable parents and suitable combine method to choose better hybrid combination.3.Through the analysis of SCA of the combinations,it concluded that the high lodging resistance combinations are follows:Jin23A/R9019,Long tefuA/Yanhui559,â…¡-32A/Yanhui559,-32A/Fuhui838,Zhong9A/Minhui63,Jin23 A/Zhenhui084, AnguanS/R713,Guangzhan63S/R713,Xuan69S/Huanghuazhan,Annong9054S/Anxua n6hao and Annong81S/Anxuan6hao etc.4.Through the correlation analysis of lodging resistance traits,it conclude that: lodging index appears significant positive correlation with plant height,the first and second internode's length,but significant correlation with long spindle and short spindle.So,the parents' lodging resistance could be improved by shorting basal internodes' length,strengthening the stalk.Only all the lodging resistance traits be considered,can we get high lodging resistance combination.5.Through the correlation analysis lodging resistance traits between F₁ and their parents,it conclude that:the plant height,long spindle,short spindle,basal internode's thickness and lodging index of F₁ are effected more by father,but the first basal internode's length are effected more by mother.So we can take advantage of this genetic phenomenon to rationalize lodging resistance traits,according to the aim of breeding,6.Through the correlation analysis between the GCA of lodging resistance traits and the GCA of yield,it conclude that:the GCA of lodging index appears significant negative correlation with the GCA of spike number per plant,significant positive correlation with spike length.,negative correlation with total grains per spike,full grains and yield,to some degree.In another word,the contradiction between lodging resistance and yield could be settled at a level through make use of SCA.