GENETIC DIVERSITY AND VARIABILITY OF INDIGENOUS LANDRACE GERMPLASM COLLECTION OF OKRA (Abelmoschus esculentus L. Moench) FROM TRADITIONAL AGRO-ECOSYSTEMS IN TRIBAL AREAS OF TELANGANA, INDIA
MEDAGAM THIRUPATHI REDDY *
Vegetable Research Station, Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad-500 030, Telangana, India.
SOMESWARA RAO PANDRAVADA
National Bureau of Plant Genetic Resources, Regional Station, Rajendranagar, Hyderabad-500 030, Telangana, India.
NEELAM SUNIL
National Bureau of Plant Genetic Resources, Regional Station, Rajendranagar, Hyderabad-500 030, Telangana, India.
NATARAJAN SIVARAJ
National Bureau of Plant Genetic Resources, Regional Station, Rajendranagar, Hyderabad-500 030, Telangana, India.
*Author to whom correspondence should be addressed.
Abstract
Okra (Abelmoschus esculentus L. Moench) is an indigenous multipurpose and multifarious vegetable crop in India. It is extensively grown in peri-urban, rural and tribal areas under different agro-ecological zones of the country. Landraces of okra are exclusively grown in the traditional agro-ecosystems in tribal niches. Twenty landraces of okra were collected through special agri-biodiversity surveys in tribal areas of Adilabad District of Telangana, India by National Bureau of Plant Genetic Resources, Regional Station, Rajendranagar during 2010-12. These landraces were augmented and evaluated along with one check 'Arka Anamika' in a randomized block design with three replications at Vegetable Research Station, Rajendranagar during kharif 2013 to assess their mean performance, genetic diversity and variability for 14 agronomic traits. Analysis of variance indicated the presence of a wide range of variability among the landraces for all the traits tested. On the basis of marketable yield, the landraces RNO-204 (248.84 g/plant), RNO-207 (242.83 g/plant) and RNO-212 (241.11 g/plant) were as promising as that of the check 'Arka Anamika' (231.91 g/plant) that will go a long way in boosting the production potential of okra in these tribal areas. Phenotypic variances and coefficients of variation were higher than the corresponding genotypic variances and coefficients of variation indicating a predominance of environmental effects on the expression of these characters. High estimates of broad sense heritability coupled with high genetic advance as percent of mean for days to 50% flowering, first flowering node, first fruiting node, number of marketable fruits per plant, marketable yield per plant and YVMV infestation on plants implicates that these traits were under the control of additive gene effect and could be effectively improved through selection. Dendrogram generated following Tocher’s method indicated that, the landraces were grouped into 10 clusters. There was no association between the geographic collection sites of landraces and their clustering.
Keywords: Broad sense heritability, clustering pattern, genetic advance, genetic divergence, genetic variability, local varieties, Tocher’s method