Biochemical and molecular evaluation of pigeonpea against Fusarium wilt

Fusarium wilt caused by Fusarium udum is the most important disease of pigeonpea that adversely affect the yield and production. Development of cultivars resistant to fusarium wilt could be an effective strategy in decreasing the production costs, improving production quality and reducing the detrimental effect of chemical on ecosystem. Twenty four different genotypes and local germplasm of pigeonpea was field tested on wilt sick soil for percent wilt incidence and the percent wilt incidence were ranged between 6.98 and 24.44. The mean wilt incidence of resistant pigeonpea genotypes was 8.53 whereas that of susceptible genotypes was 24.15%.Only five pigeonpea genotypes (BDN-711, ICP-8863, PT-012-2,PT-012-1, PT-03-129-2) recorded field wilt incidence of less than 10% and categorized as resistant. The four genotypes (PT-04-111, PT-04-360-1, PT-03-104-1 and PT-012-12) were categorized as susceptible with wilt percent between 20.1 and 40.00 and remained genotypes were moderate resistant. The mean phenol and OD phenol content of leaf tissues of resistant genotypes under wilt sick conditions was significantly higher than susceptible genotypes. The mean activity of defense related enzymes viz., β1,3-glucanase, chitinase and phenylalanine ammonia lyase was 90.11 nmoles of glucose released/mg protein/min, 12.27 nmoles of N-acetyl glucosamine released/mg protein/min and 3.46 nmoles of transcinnamic acid formed/mg protein/min respectively, in resistant genotypes under wilt sick conditions. On the basis of wilt resistant and susceptible pigeonpea genotypes screened for different defense related enzymes out of twenty four genotypes PT-012–18, ICP-8863 and BDN 711 were found promising. A reported RAPD primer OPG 08 and SCAR1 marker showed 920 and 937 bp respectively, in pigeon pea wilt resistant genotypes.