Electronic Journal of Plant Breeding, ISSN 0975-928X DOI : 10.5958/0975-928X.2016.00026.0 http://ejplantbreeding.com 189 Heterosis for yield and its related traits in Okra (Abelmoschus esculentus L. Moench) J. P. Bhatt 1 , N. A. Patel 2 , R. R. Acharya 3 and K. B. Kathiria 4 (Received: August 2015; Accepted: August 2015) 1 Senior Research Assistant, Regional Cotton Research Station, Anand Agricultural University, Viramgam-382 150 (Gujarat), India 2 Assistant Research Scientist, Main Vegetable Research Station, Anand Agricultural University, Anand-388 110 (Gujarat), India 3 I/C Head and Associate Research Scientist, Main Vegetable Research Station, Anand Agricultural University, Anand-388 110 (Gujarat), India 4 Director of Research and Dean PG Studies, Anand Agricultural University, Anand-388 110 (Gujarat), India Abstract Eight parental lines of okra and their 28 F 1 hybrids obtained from half diallel were studied to investigate the extent of heterosis for yield and yield attributing characters. The magnitude of heterosis varied from cross to cross for all the characters studied. Maximum positive heterosis for fruit yild per plant over better parent and standard check (JOH 2) was observed to be 62.12 and 44.11 per cent, respectively. The cause of heterosis may be due to its component traits, mainly, days to first flowering, nodes per plant, length of internode, fruit weight and fruits per plant. The best performing hybrid AOL 09-25 x AOL 09-26 which recorded 44.11 per cent heterosis for yield over standard check may be exploited for commercial cultivation. Key words: Abelmoschus esculentus (L.) Moench, heterosis, diallel analysis, fruit yield Introduction Okra [Abelmoschus esculentus (L.) Moench] is one of the important vegetable crop grown for its tender green pods in tropics, subtropics and warmer parts of temperate region. It is basically self-pollinated crop in which emasculation and pollination is feasible with higher success rate of fruit setting. The cost of hybrid seed production at a commercial scale may also be lower in okra due to simple floral biology, more number of seeds per cross, higher rate of successful seed setting and higher percentage of successful crosses. These characteristics offer great possibilities of crop improvement through hybridization. The magnitude of heterosis provides a basis for genetical diversity and a guide for the choice of desirable parents for developing superior F 1 hybrids to exploit hybrid vigour and for building gene pools to be employed in future breeding programme. Keeping this in view, the present investigation was carried out to know magnitude of heterosis for fruit yield and its component traits in okra. Materials and methods Eight genetically diverse parent lines of okra were crossed in all possible combinations in half diallel fashion for the present study conducted at Main Vegetable Reasearch Farm, Anand Agricultural University, Anand, Gujarat. The eight parents viz., AOL 08-10, AOL 09-24, AOL 08-2, AOL 09-25, AOL 09-26, AOL-09-27, GO-2, AOL-09-28; their 28 F1s and standard check JOH-2 were laid out in randomized block design with three replications during July 2010. The planting distance of 60 cm x 30 cm was maintained. The cultural and plant protection practices were carried out as required to raise a good crop. Observations were recorded on five randomly selected competitive plants for 9 fruit yield and its component characters viz., days to first flowering, plant height (cm), nodes per plant, length of internode (cm), primary branches per plant, fruit length (cm), fruit weight (g), fruits per plant and fruit yield per plant (g). Heterobeltiosis and standard heterosis were computed as per the methods given by Fonseca and Peterson (1968) and Meredith and Bridge (1972), respectively. Results and discussion The findings of heterosis over better parent and check (JOH-2) are presented in Table 1. Three best per se performing parents and three top ranking heterotic crosses alongwith number of crosses showing significant desirable heterosis over better parent and standard check (JOH-2) are presented in Table 2. The results indicated that the degree and direction of heterosis varied enormously for all the characters studied. Overall, the magnitude of heterotic effects were high for fruit yield per plant and primary branches per plant. Whereas, length of internode, fruit weight and fruits per plant displayed moderate heterosis. Nodes per plant, plant height and days to first flowering exhibited the least heterosis.