Inheritance of  wilt (Fusarium oxysporum  f sp. carthami) resistance in safflower

 Vrijendra Singh,  M. K. Galande,  M. B. Deshpande and  N.  Nimbkar 

Abstract

An investigation of the inheritance of wilt resistance in safflower to develop wilt resistant cultivars was undertaken at this Institute.  Four safflower crosses, involving wilt susceptible, moderately tolerant and wilt resistant genotypes, were attempted during 1996-97.  All four crosses along with their parents were screened for wilt resistance in wilt-sick plot conditions during 1997-98 and 1998-99.  However, the F₂ s and backcrosses of only two of the crosses were evaluated during 1998-99.  The observations on wilt resistance in F₂, F₃ and backcrosses of the crosses under examination revealed the control of inhibitory gene action in the expression of wilt resistance in safflower.  The wilt in the present case is caused by a dominant gene, however, its expression is inhibited in the presence of a dominant inhibitor gene.  Slight variation in wilt resistance in two years of  F₁  evaluation indicated the possible role of modifier genes in altering the expression of wilt resistance in safflower.

 Key words:  Fusarium oxysporum, inheritance, inhibitory gene action, modifier gene