MSc

An experiment was carried out in the Department of Olericulture, College of Horticulture, Kerala Agricultural University, Vellanikkara during August 2007 - January 2008 to analyze the performance of different accessions of clove bean Ipomoea muricata (L.) Jacq. The major objectives of the study were to genetically catalogue the germplasm and to assess the genetic variability, divergence, heritability, genetic gain and correlation of different traits with yield. Twenty five accessions collected from different parts of Kerala were grown in randomized block design with three replications.
Cataloguing of the germplasm evidenced significant differences for the characters like vine length, days to first flower production, days to first harvest, length and weight of pedicel, length of fruit, yield per plant, duration of the crop, number of harvests and contents of vitamin C, calcium and crude fibre. There was also much variability in the germplasm with regard to colour shades of vine, flower and fruit.
The accession IM-14 was found to be the highest yielder (4.24kg/plant) coupled with maximum length (3.675cm), girth (4.49cm) and weight of pedicel (93.27g) and length (2.8cm), girth (6.61cm) and weight of fruits (3.27g). Maximum vine length was observed in IM-7 (414.48cm). The accession IM-15 was the second best yielder (4.13 kg/plant) with superior yield contributing characters.
Among quality attributes, protein content was found to be highest in IM-21, phosphorus in IM-2 and crude fibre in IM-10 and IM-3. The iron content ranged from 0.13mg/100g to 0.19mg/100g, vitamin C ranged from 24mg/100g to 48 mg/100g and calcium content ranged from 230.67mg/100g to 209.79mg/100g.
Highest genotypic and phenotypic coefficients of variation were observed for weight of pedicel, yield per plant and crude fibre content. High heritability coupled with genetic gain was observed for yield per plant. The 25 accessions were grouped into six clusters and no parallelism between geographical distribution and genetic diversity was observed.
Strong association was revealed between yield and length, girth and weight of pedicel and weight of fruit. Highest positive direct effect on yield was contributed by weight of individual fruits.
A selection model was also formulated using characters like length, girth and weight of pedicel, length and girth of fruit, days to first flower production, vine length, protein, phosphorus, iron, ascorbic acid and crude fibre. Based on selection index accession IM-14 was identified as the best performer followed by the accessions IM-15, IM-12 and IM-11.