PhD

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.