Breeding for an ideal plant type in Brassica rapa L.

摘要

The investigation was set out to study the mean performance, heritability and genetic gain of yield and its components of Brassica rapa genotypes. Six genotypes of B. rapa were chosen for one or more several important traits for genetic improvement and were crossed in a half diallel design and genetic analyses were conducted based on different generations. The inherent genetic differences among the genotypes were found which might be exploited through selection. The life span of the parent SAU 3 was the lowest but its yield was moderate compared to other parents. The highest yield and 1000-seed weight were noticed in TORI 7 and its 80% maturity was achieved in 81 days. In case of hybrids, the lowest life time of 79.33 days was found in SAU 3 X TORI 7. The highest yield per plant and 1000-seed weight was observed in BARI 6 X SAU 2 and BARI 6 X SAU 1, respectively. The highest heritability was recorded by days to maturity (99.99%) in the hybrid P1×P3 followed by plant height (99.93%) in P2×P6 and length of siliqua (99.83%) in P1×P4. In the cross P1×P2, length of siliqua showed high (58.06%) narrow sense heritability with very low genetic gain (0.65). Considering the yield contributing traits in connection with the heritability and genetic gain, it might be concluded that TORI 7 was the ideal parent and the hybrid combination BARI 6 X SAU1 was the ideal hybrid for B. rapa.