MSc

An experiment on “Heterosis and combining ability analysis to leaf curl virus in chilli” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Kerala Agricultural University during the period 2012-2014 to identify the best general combiners and specific combiners for developing superior cross combinations, the inheritance pattern of yield, yield attributes and qualitative traits and resistance to leaf curl virus disease.
Six parents viz, Ujwala, Anugraha, Vellayani Athulya, Jwalasakhi, Pant C1 and Pusa Sadabahar were crossed in a diallel pattern and the resultant 30 hybrids were evaluated in full diallel fashion. The field experiment was laid out in randomized block design (RBD) with three replications.
Analysis of variance revealed significant differences among the genotypes for all the traits. Measurement of heterosis was carried out considering parent Ujwala (P1) as check and results revealed that standard heterosis was positive and significant in the combinations, Vellayani Athulya x Pusa Sadabahar (P3 x P6), Pusa Sadabahar x Vellayani Athulya (P6 x P3), Pusa Sadabahar x Jwalasakhi (P6 x P4) and Vellayani Athulya x Jwalasakhi (P3 x P4) for all the traits. The crosses, Vellayani Athulya x Pusa Sadabahar (P3 x P6), Pusa Sadabahar x Ujwala (P6 x P1), Jwalasakhi x Pusa Sadabahar (P4 x P6) were exhibited positive and significant standard heterosis for yield and yield related traits. The cross Pant C1 x Vellayani Athulya (P5 x P3) exhibited negative and significant standard heterosis for incidence of leaf curl virus disease.
Combining ability analysis showed significant gca, sca , rca variances and gca, sca effects for all the traits. Moreover gca/sca variance ratio indicated preponderance of dominance / non-additive gene action for the inheritance of all traits. Among parents, Pusa Sadabahar exhibited positive and significant gca effect for plant height, branches per plant, number of fruits per plant, yield per plot, total soluble protein, total carbohydrate, poly phenol oxidase, vitamin C, oleoresin and negative and significant effect for incidence of leaf curl virus disease. Among crosses, Vellayani Athulya x Pusa Sadabhar (P3 x P6) exhibited positive and significant sca effect for fruit weight and yield per plot whereas; Ujwala x Vellayani Athulya (P1 x P3) exhibited negative and significant sca effect for leaf curl virus disease incidence.
Among the biochemical parameters studied, membrane integrity in terms of % leakage had positive association with LCV disease. Total soluble protein content, phenol content, total CHO content, poly phenol oxidase, vitamin C and oleoresin had negative association with LCV disease.
Artificial screening was carried out in insect proof cage to confirm the resistance/tolerance to leaf curl virus disease among the superior crosses identified in the field experiment. Crosses Vellayani Athulya x Pusa Sadabahar (P3 x P6) and Pant C1 x Vellayani Athulya (P5 x P3) were exhibited tolerance for leaf curl disease incidence.
From the present study Vellayani Athulya x Pusa Sadabahar (P3 x P6), Pusa Sadabahar x Vellayani Athulya (P6 x P3) and Pant C1 x Vellayani Athulya (P5 x P3) were identified as superior crosses and these can be used for improving yield and quality trait like resistance to leaf curl virus disease in future breeding programme.