Heterobeltiosis, inbreeding depression and heritability study in okra(Abelmoschus esculentus (L.) Moench)

P1, P2, F1, F2, BC1 and BC2 generations of six crosses viz., HRB-55 x AOL-05-4, VRO-5 x Red Long, VRO-6 x AOL-05- 3, GO-2 x AOL-04-3, Arka Anamika x AOL-03-1 and Parbhani Kranti x AOL-03-6 were used to study heterobeltiosis, inbreeding depression and heritability for days to first flowering, days to first picking, plant height, primary branches per plant, stem girth, fruit length, fruit girth, fruit weight, fruits per plant and fruit yield per plant in okra (A. esculentus (L.) Moench). HRB-55 x AOL-05-4 showed heterobeltiosis in desirable direction for almost all the fruit yield and its contributing characters particularly, 94.06 per cent for fruit yield per plant and 86.12 per cent fruits per plant. Moderate to high narrow sense heritability was observed for primary branches per plant in the crosses HRB-55 x AOL-05-4 (E1), VRO-6 x AOL-05-3 (E1) and Parbhani Kranti x AOL-03-6 (E2); fruit girth in the crosses VRO-5 x Red Long (E1), VRO- 6 x AOL-05-3 (E1), GO-2 x AOL-04-3 (E1) and Arka Anamika x AOL-03-1 (E1); fruit weight in the crosses HRB-55 x AOL-05-4 (E2), VRO-5 x Red Long (E1) and GO-2 x AOL-04-3 (E2). The highest heritability identified 99.35 per cent for fruit length in the cross HRB-55 x AOL-05-4. The results of heterosbeltiosis revealed that the cross HRB-55 x AOL- 05-4 may be exploited for fruit yield and its component traits. The positive and significant inbreeding depression observed for days to first flowering in cross, GO-2 x AOL-04-3 (E1 and E2) and for days to first picking in the crosses HRB-55 x AOL-05-4 (E2), VRO-5 x Red Long (E2), GO-2 x AOL-04-3 (E2) and Parbhani Kranti x AOL-03-6 (E2). This indicates to obtain desirable segregants for earliness in subsequent segregating generations. The negative and significant inbreeding depression which is desirable for okra crop improvement also observed for different traits across the environments viz., twelve cases each in the crosses HRB-55 x AOL-05-4 and VRO-5 x Red Long; four cases in cross VRO-6 x AOL-05-3; eight cases in cross GO-2 x AOL-04-3; seven cases in cross Arka Anamika x AOL-03-6 and six cases in cross Parbhani Kranti x AOL-03-6. These findings would be useful for the improvement of fruit yield and its quality traits while handling the segregating generation for the development of improved varieties.