Relationship between leaf stages and epistasis for resistance to Stagonospora nodorum in durum wheat

Genetics and Molecular Biology

Fethi Bnejdi²  Mourad Saadoun¹  Mouna Naouari²  Mohamed El Gazzah² 

[1] ,Université Tunis El Manar Faculté des Sciences de Tunis Département de Biologie,Tunisia

关键词: adaptability;    inheritance;    leaf stage;    Stagonospora nodorum blotch;   

DOI  :  10.1590/S1415-47572012005000033

来源: SciELO

【 摘 要 】

Ten varieties and eight generations (2F1, 2F2, 2B1 and 2B2) of durum wheat derived from two crosses were evaluated for resistance to natural infection by Stagonospora nodorum blotch (SNB) at the 2-3 and 6-7 leaf stages at two sites over two years. There were significant differences in the incidence of SNB between leaf stages in most of the wheat varieties, with resistance being most evident at the 6-7 leaf stage. Separate analyses of the mean values for each generation showed that the genetic mechanism of defense against the pathogen depended upon the leaf stage. At the 2-3 leaf stage, only additive and dominance effects were implicated in the control of SNB for the two crosses at the two sites and for the two replications. For the 6-7 leaf stage, inheritance was more complicated and an epistatic effect was involved. Narrow-sense heritability values (range: 0.63-0.67) were consistent between crosses and leaf stages. These findings indicate a lack of resistance to SNB at the 2-3 leaf stage whereas resistance was observed at the 6-7 leaf stage and involved the genetic mechanisms of plant defense such as epistasis.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License