水稻中間母本系統들의 稻熱病抵抗性 遺傳分析

Genetic Analysis of the Resistance to Blast of the Two Intermediate Breeding Lines in Rice(Oryza saliva L.)

To investigate the genetic behavior of the two intermediate breeding lines (IR 5533 and IR 3259), genetic analysis for resistance to rice blast in the F₂ population derived from the crosses between the two intermediate breeding lines and with their resistant parents, Tetep, Carreon, and with susceptible varieties Milyang 23 and Yushin were carried out. F₂ plants from the crosses between two breeding lines and susceptible varieties showed a good fit to a segregation ratio of 13:3, which indicating the two breeding lines had at least two resistant genes. The resistant genes in the two breeding lines were appeared to be the same or allelic because that the susceptible plants were not found among F₂ plants from the cross between IR5533 and IR3259. The varieties, Tetep and Carreon were also appeared to have two non-allelic resistant genes because that the segregation ratio in the F₂ plants was fifteen resistant and one susceptible. (wr, vr,) graph showed that IR 5533 had the most dominant genes, which suggesting the both resistant genes from Tetep and Carreon were transferred in it, whereas IR 3259 had the lower resistance than Tetep, which suggesing the resistant genes from Tetep was not completely transferred into IR3259. The positve correlation coeffeient (r) between parental order of performance and (wr,+vr,) both in lesion length and lesion number indicated that resistance was dominant.