MSc

The study entitled “Molecular characterization of brinjal (Solanum
melongena L.) genotypes and their performance assessment in summer” was
conducted at the Department of Plant Breeding and Genetics, College of
Agriculture, Padannakkad, Kasaragod during 2020-2022. The main objectives of
the present study were to assess the performance of brinjal genotypes in summer
season and to characterize them using RAPD, ISSR and SSR markers. The
experimental material consisted of 30 accessions which included 11 collections
from North Kerala, 16 accessions from NBPGR regional station, Thrissur and
three KAU-released varieties (Ponny, Haritha and Surya).
The experiment was laid out in a randomized block design with 30
genotypes in three replications and observations were recorded for 26
morphological characters. The results of analysis of variance revealed significant
differences for all the characters indicating high genetic variability among the
accessions. The genotypes SM-9, SM-19 and SM-14 showed superiority for fruit
yield per plant (3204.73 g, 3017.90 g, 2484.50 g), fruits per plant (41.67, 36.67
and 53.33) and marketable fruit yield (3138.37 g, 2946.17 g, 2450.13 g).
Correlation and path analysis revealed total number of fruits, fruit width and single
fruit weight displayed a positive significant correlation and positive direct effect
with fruit yield per plant explaining a true association of these traits with yield.
The PCA biplot showed marketable fruit yield, single fruit weight and total fruits
per plant displayed greater phenotypic contribution towards yield. SM-19, SM-12
and SM-10 are found superior due to their close proximity to the yield and its
contributing vectors, while SM-9 and SM-14 were found to be more diverse
among all the genotypes.
The genetic diversity analysis based on Mahalanobis D2
statistics for 22
morphological traits grouped the thirty accessions into nine clusters. The character
single fruit weight contributed maximum towards diversity. The highest intracluster distance was recorded in cluster I followed by cluster IV. The maximum
inter-cluster distance was recorded between clusters IV and IX followed by
clusters IV and VIII exhibiting a wide diversity between these clusters providing
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scope for hybridization between superior genotypes of these clusters. The
accessions SM-10, SM-15, SM-9 and SM-19 showed superior ranking in their
respective clusters based on three yield attributes total fruits per plant, single fruit
weight and marketable fruit yield identified in association and divergence
analysis.
The 30 brinjal genotypes were characterized using RAPD, ISSR and SSR
markers. The molecular investigation with 15 RAPD markers amplified 48
effective alleles. The highest value for number of effective alleles (4.83), PIC
(0.80) and marker index (2.86) was revealed for OPC10. Based on UPGMA-based
Jaccard’s similarity coefficient the 30 accessions divided into three major groups
at 0.72 similarity. Six (out of 10) ISSR markers amplified 24 effective alleles. The
highest value for number of effective alleles (5.25), PIC (0.857) and marker index
(4.031) was revealed for UBC888. UPGMA clustering divided the 30 accessions
into 3 clusters at 0.78 similarity. The ten SSR markers amplified 17 effective
alleles. The highest value for number of effective alleles (1.99), PIC (0.374) and
marker index (0.511) was revealed for EEMS24. Based on UPGMA clustering
the 30 accessions divided into three major groups at 0.61 similarity. The
dendrogram (UPGMA) of pooled data yielded three major clusters at 0.76
similarity. The PCA clustering of pooled data displayed SM-14 and S.incanum to
be diverse among all the accessions.
The present study resulted in identification of high-yielding and diverse
lines amongst the collection of the brinjal genotypes used. Based on superior
performance for yield in summer season and pooled molecular divergence
analysis, the melongena accessions SM-2, SM-9, SM-10, SM-12, SM-14 and SM19 were found to be superior and can be considered as promising parents in future
crossing programs to develop heterotic hybrids.