Improvement Efficiency of Recurrent Selection for the Combining Ability of Yield Trait in Maize Population Yuzong 5

Abstract

Maize population has the extensive hereditary basis and rich hereditary variation,and therefore is the source of good inbred lines cultivated.Improvement of maize population is important to create new germplasm and breed excellent inbred lines.In this study,30 testcrossing combinations that Huangzaosi,Dan 340,Zhong Syn 5,Qi 319,Ye 478,and Mo17 crossed with five cycle improved populations according to NC II design were evaluated in two environments.The results showed that the recurrent selection method gained a good result for yield per plant of the population and the gain of hybrid grain yields of testcross combi-nations between improved populations per cycle and testing cultivars increased by 10%.Both half-sib recurrent selection(HS-RS) and half-sib reciprocal recurrent selection(HS-RRS) were good methods for improving the general combining ability(GCA) of grain yield in the populations and the GCA was improved in very cycle for the populations.After improvement of three cycles for Yuzong 5 by HS-RS,the GCA increased from -11.63 to 5.57 with highly significant probability difference at the level by C3 comparing with C0.After improvement of one cycle for Yuzong 5 by HS-RRS,the GCA increased from 5.57 to 9.75 by C4 com-paring with C3.The analysis of special combining ability(SCA) showed that the SCA of improved Yuzong 5 × Huangzaosi had certain enhancement,indicating that improvement of Yuzong 5 developed steadily toward the heterotic pattern of Reid×SiPT.