Inheritance of duration from sowing to first flowering in pigeonpea

Duration from sowing to flowering is the most important trait influencing adaptation in pigeonpea ( Cajanus cajan), but the inheritance of this trait has not been elucidated clearly. Crosses were made between two early (60 to 70d) and one late (160 to 170d) flowering pigeonpea genotype and F-1, F-2 and BC1 populations produced. These populations, comprising 60 to 100 parents, 30 F-1, 400 F-2 and 40 to 50 BC1 plants, were grown under natural (mean 13.4 hd(-1)) and artificially extended (to 15 hd(-1)) daylength and duration from sowing to first flowering recorded. Genetic analysis of the segregation ratios, supported by Chi-square tests, indicated that the duration from sowing to flowering in each of the crosses was controlled by two genes assorting independently and with predominantly additive quantitative effects. The segregation patterns were most clearly defined in the 15 hd(-1) daylength.