Four susceptible pigeonpea lines viz: PRG-100, PRG-88, LRG-30 and ICPL-85063 and two
resistant lines ICP-8863 and ICPL-87119 were selected for crossing to study the inheritance
pattern of resistance to Fusarium wilt. Out of the 8 cross combinations possible five crosses viz:
PRG-100x ICP-8863, PRG-88 x ICP-8863, LRG-30 x ICP-8863, ICPL-85063 x ICP-8863 and
PRG-100 x ICPL-87119 were selected wherein sufficient population was there to interpret results
based on 2 test. The progeny (F1’s) from these crosses were also resistant like their resistant
parents. The F2 population of PRG-100x ICP-8863, LRG-30 x ICP-8863 and ICPL-85063 x ICP-
8863 segregated in a phenotypic ratio of 13R: 3S in all the crosses. When back crossed to
resistant parent ICP-8863, the population segregated in 3R:1S phenotypic ratio; and when back
crossed to the susceptible parent it segregated into 1R:1S phenotypic ratio. For the crosses
PRG-88x ICP-8863 and PRG-100 x ICPL-87119, the F2 population segregated in 9R:7S ratio.
The back crosses population (B1) to the resistant parent of both crosses segregated in phenotypic
ratio of 3R:1S; and to the susceptible parent segregated in a ratio of 1R:1S. Inheritance studies
on Fusarium wilt resistance affirmed the dominance of resistance to susceptibility and the role
of two gene interactions viz: inhibitory (13:3) and complementary (9:7) type.