Stability analysis and molecular characterization of F1 hybrids in brinjal (Solanum melongena L.)

Abstract

Stability analysis helps in assessing genotype × environment interaction in order to identify stable genotypes in large multi-environment trials. Therefore the present study entitled “Stability analysis and molecular characterization of F1 hybrids in brinjal (Solanum melongena L.)” was carried out to evaluate ten hybrids along with one check across four locations. The locations selected for trials were College of Agriculture, Vellayani and farmer’s fields at Thiruvalla, Sadanandapuram and Kayamkulam in Kerala. The trial seasons were kharif (2015- 16) and summer (2016-17). The objective was to study the performance of superior hybrids over different locations and seasons from heterotic crosses of brinjal and to confirm the hybridity using SSR markers. Randomized block design with four replications was employed. Stability and adaptability of yield and yield attributing characters of hybrids were analysed by Eberhart-Russell model (1966). Pooled analysis of variance revealed significant differences among the genotypes, environments and genotype × environment interaction for all the characters studied. The indication was that the hybrids responded differently to changes in the environment. Promising hybrids were identified on the basis of stability parameters viz., overall mean, regression coefficient (bi) and deviation from regression (S2di). In kharif season, the hybrid Wardha local × Palakurthi local was observed to be stable and widely adapted to all environments for days to first flowering, number of fruits plant-1, fruit weight, fruit length, fruit girth, calyx length, yield plant-1, yield plot-1 and plant height. The hybrid Wardha local × Swetha was identified as stable with regard to fruit weight, yield plant-1 and yield plot-1. The hybrid Wardha local × Vellayani local was identified as stable for favourable environments with regard to fruit length, yield plant-1 and yield plot-1. The hybrid Surya × Vellayani local was found stable for poor environments with regard to days to first flowering. Stability analysis for the summer season crop also revealed the hybrid Wardha local × Palakurthi local as stable across all environments with respect to days to first flowering, days to first harvest, number of fruits plant-1, fruit weight, fruit length and yield plant-1. Swetha × Vellayani local hybrid was stable across all environments with regard to days to first harvest, fruit weight, fruit length, calyx length, yield plant-1, yield plot-1 and plant height. The hybrid Surya × NBR-38 was found stable with respect to yield plant-1, yield plot-1 and plant height for favourable environments. Qualitative characters viz., total phenols, total sugars and vitamin C content and biotic stress traits viz., shoot and fruit borer infestation and bacterial wilt incidence were recorded for the eleven hybrids in kharif and summer season in all four locations. On the basis of overall mean performance of hybrids, results illustrated that the hybrid Swetha × Vellayani local recorded the highest values for total phenols and the hybrid NBR-38 × Vellayani local recorded the lowest values. Total sugar content was highest in Wardha local × Swetha and NBR-38 × Selection Pooja and lowest in Surya × NBR-38. The hybrid Neelima and Swetha × Vellayani local recorded higher quantity of vitamin C and NBR-38 × Vellayani local and NBR-38 × Selection Pooja recorded the lowest values. The hybrids Wardha local × Palakurthi local, Swetha × Vellayani local and Neelima recorded minimum infestation of shoot and fruit borer and was found resistant to bacterial wilt also. Hybrids and their parental lines were characterized using SSR markers. Among the four markers studied, three markers viz., emb01M15, eme08D09 and CSM31 were found to be polymorphic among the parental lines of respective hybrids viz., Surya × NBR-38, Surya × Vellayani local, NBR-38 × Selection Pooja, Swetha × Vellayani local, Wardha local × Swetha, Wardha local × Palakurthi local, Palakurthi local × Vellayani local and NBR-38 × Vellayani local which could be used for ensuring the genetic purity of respective parental lines and hybrids. F2 families viz., Wardha local × Palakurthi local, Wardha local × Swetha, Wardha local × Vellayani local and Swetha × Vellayani local were selected on the basis of yield performance from F1 for further evaluation. F2 populations revealed that family Wardha local × Palakurthi local and Wardha local × Vellayani local were superior in yield performance and yield attributing characters. The present investigation revealed that the hybrids Wardha local × Palakurthi local and Swetha × Vellayani local were stable and widely adapted over different locations and seasons and the hybridity was confirmed with the SSR markers, emb01M15 and eme08D09.