PhD

The research work on “Stability analysis and molecular characterization of F1 hybrids in okra (Abelmoschus esculentus (L.) Moench)” was carried out with ten hybrids and two check varieties over four locations viz., College of Agriculture, Vellayani, FSRS, Kottarakkara, Farmer’s fields at Kayamkulam and Thiruvalla during kharif and summer to study the performance of superior hybrids over different locations and seasons from heterotic crosses and to confirm the hybridity using SSR markers.
In the pooled analysis of variance for evaluation of F1 hybrids over locations and seasons, significant differences among the genotypes and environments were noticed for all the characters studied, suggesting genotypes interacted significantly with environments.
Stability analysis revealed the hybrids viz., Thirumala local x Mallapalli local and Thirumala local x Kattakada local as stable over all locations for fruit yield per plant, fruit girth, fruit length, number of fruits per plant, YVM incidence, fruit and shoot borer infestation during kharif season. The hybrid Thirumala local x Mallapalli was superior to check varieties. Holavanalli local x Mallapalli local was identified as stable hybrid for favourable environments with regard to fruit yield per plant, fruit girth, fruit weight and crop duration. The hybrid Thirumala local x Punjab Phalgani was found to be suitable for poor environments. The hybrids Thirumala local x Mallapalli local and IC1012-1 x Mallapalli local were found stable for days to first flowering.
The stability analysis during summer season also revealed the hybrids Thirumala local x Kattakada local and Thirumala local x Mallapalli local along with Thirumala local x Punjab Phalgani as stable in all locations for fruit yield per plant, YVM incidence, fruit and shoot borer infestation. The hybrids Kunnapuzha local x Kattakada local and Halu Bhendi x Kattakada local were suitable for poor environments.
Three superior hybrids and their parental lines were characterized using SSR markers. Among the eight primers analysed, AVRDC-Okra64 was effective for varietal identification and hybrid testing of Thirumala local x Punjab Phalgani with specific banding profile. Multiplexing with two SSR primers (AVRDC-Okra64 and MITC 27) showed a clear differentiation of the parents and hybrids of Thirumala local x Mallapalli local and Thirumala local x Kattakada local.
The present investigation revealed that the hybrids Thirumala local x Mallapalli local, Thirumala local x Kattakada and Thirumala local x Punjab Phalgani local are stable over different locations and seasons. AVRDC-Okra64 and MITC 27 can be used as referral markers for identification of parents and hybrids.