抗玉米大斑病单基因处于杂合状态时的效应

The effects of resistant monogene in heterozygote for Exserohilum turcicum in Maize

单基因Ht1、Ht2、Ht3、HtN处于不同水平抗性杂合状态时对大斑病抗性的基因效应不同。通过单基因Ht1、Ht2、Ht3、HtN与同一水平抗性自交系以及与不同水平抗性自交系组配,研究单基因处于杂合状态时在控制病斑数量、面积、病斑扩展速度、产孢量和潜伏期等方面的单基因、多基因的联合效应。结果表明,抗性单基因HtN处于F1代杂合状态时,控制病斑数和病斑面积的效应最强;单基因处于杂合状态时,湿培48 h病斑全部能产生分生孢子,且处于同一水平抗性杂合状态时,Ht1控制产孢量的效应最强;Ht1处于中水平、Ht3处于高水平和HtN处于低水平垂直抗性杂合状态下,控制病斑扩展效应最强;而Ht2处于高水平垂直抗性杂合状态下,控制病斑扩展效应最弱;抗性单基因处于杂合状态下,控制潜伏期多表现超亲现象,HtN控制病害潜伏期比其它单基因显著。

The effects of monogene Ht1,Ht2,Ht3,and HtN in different levels of heterozygote were different for Exserohilum turcicum in Maize.Monogene Ht1,Ht2,Ht3,and HtN were crossed with inbreds of same resistant level and different resistant level to study the monogenic effects and polygenic effects on spots number,size,spread speed,spore production and incubation period.The results showed that resistant gene HtN in F1 heterozygote was the most effective on controlling spots number and size;all monogene in heterozygote could produce spore by moisture culture and resistant gene Ht1 was the most effective;resistant gene Ht1 in medium level,Ht3 in high level,and HtN in low level of vertical resistance of heterozygote,were the most effective on controlling spots spread;while Ht2 in high level of vertical resistance of heterozygote was the most ineffective on controlling spots spread;and all resistant monogene in heterozygote showed superior to their parents on controlling incubation period and gene HtN was more significant than other genes.