Genetic potential and heritability studies for some polygenic traits in cotton (gossypium hirsutum l.)

The research work comprising genetic potential and heritability in a 6 X 6 F1 diallel cross of upland cotton was conducted during 2008 and 2009 at Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan. The parental cultivars used in the diallel crosses were CIM-473, CIM-496, CIM-499, CIM-506, CIM-554 and CIM-707. Genotypes manifested significant variations for plant height, monopodia plant/sup -1/, sympodia plant/sup -1/, bolls sympodia/sup -1/, bolls plant/sup -1/ and seed cotton yield plant/sup -1/. On average, the F1 hybrids manifested significant increase over parents for plant height (11.5%), sympodia plant/sup -1/ (6.34%), bolls sympodia/sup 1/(4.83%), bolls plant/sup -1/ (9.95%) and seed cotton yield plant/sup -1/ (26.07%). Broad sense heritability was high with expected response to selection being for plant height (0.81 and 17.85 cm), monopodia plant/sup -1/(0.95 and 0.49), sympodia plant/sup -1/(0.92 and 4.00), bolls sympodia/sup -1/ (0.90 and 0.74), bolls plant/sup -1/ (0.90 and 9.45) and seed cotton yield plant/sup -1/ (0.76 and 38.84 g), respectively. Seed cotton yield exhibited significant positive correlation with all traits except monopodia plant/sup -1/. Parental cultivars CIM-506 and CIM-554 performed better in their specific cross combinations and revealed reasonable mean performance. The F1 hybrids CIM-506 X CIM-554, CIM-473 X CIM-554, CIM-554 X CIM-506 and CIM-554 X CIM-707 manifested best genetic potential for majority of the traits. Results also revealed that the above four F1 hybrids have the potential to be used for hybrid cotton production and can also be studied in segregating generations for further improvement and stability in their genetic potential for seed cotton yield and its components. (author)