Heterosis for seed and seedling traits in papaya

The current study was aimed to explore the heterosis expressed in the seed and seedlings of 36 papaya hybrids originating from the 6 inbred lines. The results revealed the manifestation of heterosis, occurred in the seed and seedling stage of papaya. The cross combinations, P-9-5 × P-7-2, P-9-12 × PN and PN × P-9-5 exhibited positive average heterosis and heterobeltiosis for physical seed traits. The genotypes, P-9-5, P-9-12, P-9-5 × P-9-12 and P-9-12 × P-9-5 were observed with positive mid-parent heterosis and heterobeltiosis for the seedling traits. The hybrid, P-7-9 × PN and PS3 × P-7-9 showed positive average heterosis (5.89% and 9.91%) and heterobeltiosis (3.41% and 2.09%) for germination percentage, respectively. Whereas in case of seedling length and weight (fresh and dry), the hybrid combination, P-9-5 × P-9-12 exhibited the positive heterosis. The heterosis effect estimated helped us to identify the superior performing hybrids like, PN × P-7-2, PN × P-9-5, P-7-2 × PN, P-7-2 × P-7-9, P-7-9 × P-9-5, P-9-5 × P-7-2, P-9-5 × P-9-12, P-9-12 × PN, P-9-12 × P-7-2, P-9-12 × P-95and PS3 × P-7-9, in the initial stage of seedling development.