Screening germplasm lines for identification of resistant source against gray mold disease (Amphobotrys ricini (N.F. Buchw.) Hennebert) of castor

The present study was aimed to screen castor germplasm lines varying in wax content against gray mold disease for the identification of resistance source under in vitro conditions using detached spike and detached capsule technique. Out of thirty-three lines screened against gray mold under in vitro conditions six lines with low wax content viz., RG-1754 (0.24 µg/mg), RG-1875 (0.12 µg/mg), RG-1915 (0.21 µg/mg), RG-1919 (0.24 µg/mg), RG-1972 (0.08 µg/mg) and RG-1926 (0.08 µg/mg) recorded significantly low levels of infection ranging from 10 to 20 per cent 7 days after inoculation. Whereas the susceptible cultivar DCH -519 has recorded disease severity of more than 90 %. The pearman's rank correlation analysis showed a strong positive relation between disease severity and capsule wax content, with p < 0.01 and r = 0.884.