4个水稻纹枯病新抗源品系的抗病性遗传分析

目的]对中大304、MR1400、T1006和大区50等4个抗源进行稻纹枯病抗性遗传分析,为利用这些资源进行基因定位与育种提供依据.方法]用感稻纹枯病的粳稻品种中野1211作母本,4个籼稻抗源品种中大304、MR1400、T1006和大区50分别作父本,组配4个杂交组合,获得F1和F2群体.用广西稻纹枯病菌优势致病型菌株AG-I-IA、GX-2以牙签嵌入法对F1和F2进行接种鉴定和遗传分析.结果]抗源中大304、MR1400、T1006和大区50均表现中抗纹枯病,中野1211高感纹枯病;4个杂种F1植株对纹枯病的抗病等级为4.0～8.0级,表现为中抗～高感,平均为5.1～6.1级,为中感,群体抗性呈连续性分布;F2群体纹枯病抗性分离谱较广,抗性等级变化范围为2.0～9.0（R～HS）,群体抗性呈连续单峰分布.抗源中大304、MR1400、T1006和大区50对水稻纹枯病的抗性遗传率分别为15.4％、31.1％、47.7％和43.8％.结论]4个杂交组合的F1群体对纹枯病的抗性均介于其双亲之间,抗源中大304、MR1400、T1006和大区50对水稻纹枯病的抗性均为数量性状,受微效多基因控制.

Genetic analysis of resistance to sheath blight in four new rice resistance sources

Objective]Genetic analysis of resistance to sheath blight was analyzed in resistance sources of ZD 304,MR1400,T1006 and DQ50 to provide references for gene mapping and breeding.Method]Four indica rice resistance sources ZD304,MR1400,T1006 and DQ50 （male parent） were crossed with japonica rice ZY1211 （female parent） which was highly susceptible to sheath blight to get F1 and F2 used for genetic analysis by using toothpick embedding inoculation method with Guangxi prevailing strain AG-I-IA and GX-2.Result]ZD 304,MR1400,T1006 and DQ50 were moderately susceptible to sheath blight.ZY1211 was highly susceptible to sheath blight.The resistances of F1 in the 4 cross combinations were 4.0-8.0 （M-HS） grade with the average grade of 5.1-6.1.The population resistance showed continuous distribution.The F2 population segregated greatly and showed continuous unimodal distribution with the grade of 2.0-9.0（R-HS）.Among the resistance resources,the resistance heritability of ZD304,MR1400,T1006 and DQS0 was 15.4％,31.1％,47.7％ and 43.8％,respectively.Conclusion]Resistance of ZD304,MR1400,T1006 and DQ50 to sheath blight was quantitative trait and controlled by micro-multiple genes,and the resistances of F1 popuations in the 4 cross combinations were between their parents.