|
In order to understand the level of conventional rice breeding conditions,a total of 37 cultivars conventional rice varieties in the 50’s,60,70’s,80’s,90’s and 2000’s are collected, and prepared 111 hybrids with three restorer lines.This paper compares the differences of major agronomic traits and heterosis in conventional indica rice cultivated in different eras. The main results are as follow:1)early indica in 50’s hybrided with currently hybride rice male parents can generate strong heterosis,mid-late indica’s conbinations negtive heterosis in most; early indica in 60、70’s hybrided with early male parents generate negtive heterosis in most,but with mid-late male parent strong heterosis generated, mid-late indica’s conbinations have weak heterosis; conbinations of early indica in 80’s、90’s and 2000’s are not different in heterosis which is not strong, mid-late indica hybrided with early male parents can generate strong heterosis,but hybrided with mid-late male parents,conbinations have weak mid-parent and transgressive s heterosis and conbinations of in 80’s、90’s have strong Superstandard Heterosis.2) Xiangzao143, Sixi zhan, Xiangwanxian 2, Xiangwanxian 9, available strong heterosis combination have the potential of being transformed into CMS.3) 48 pairs of SSR primers amplified a total of 74 bands, of which 49 (62%) were polymorphic, Each pair of primers can detect no more than three polymorphisms,1.54 average. The results show that the tested material has good genetic diversity. The clustering results show that:In the genetic similarity coefficient of 0.57,40 clustered into a class, In the genetic similarity coefficient of 0.592, the test materials divided into two categories.4) Correlation analysis showed that:Plant height, grain weight and genetic distance as excessive advantage of a significant positive correlation,but it is little correlation.with yield per plant,biological yield,production relations are not significant.
|