M Sc

The study entitled “Characterization of brinjal (Solanum melongena L.) and
its wild relatives” was carried out at the Department of Plant Breeding and
Genetics, College of Agriculture, Padannakkad during 2018-2020. The main
objectives of the study was to characterize the brinjal genotypes and its wild
relatives based on morphological characters; analyze the genetic variability in
collected accessions and to develop selection index for cultivated types. The
experimental meterial consisted of 25 S. melongena accessions and five wild
relatives (S. mammosum, S. macrocarpon, S. insanum, S. incanum and S. gilo)
collected from North Kerala (Malappuram-11, Kozhikode-5, Kannur-4, Kasaragod-
3, Wayanad-1) and Regional station, NBPGR, Thrissur (6).
The passport data of thirty accessions were prepared and these were evaluated for
17 qualitative and 22 quantitative characters based on IPGRI descriptor in field
experiment laid out in Randomized Block Design with three replications. The
morphological characterization based on qualitative characters showed wide
variation for stem colour, leaf lobing, fruit shape and fruit colour. The results of
analysis of variance indicated significant differences for all the quantitative
characters indicating presence of high genetic variability. The mean performance of
genotypes revealed distinct variation between cultivated and wild accessions for
most of the characters. The wild accessions recorded lower values for fruit yield
and fruit weight but longer duration for flowering and fruit set. Eight S. melongena
accessions (SM 27, SM 25, SM 23, SM 20, SM 10, SM 23, SM 24 and SM 8) had
high fruit yield per plant (more than 1000 g). The accession SM 27 had shown
superiority for important yield component traits like fruit yield, fruit diameter and
fruit weight. Among all accessions, the green fruited S. melongena accession SM-
25 showed lesser incidence of shoot and fruit borer. Three wild accessions S.
mammosum (SM 22), S. gilo (SM 29) and S. insanum (SM 30) showed no
incidence of fruit and shoot borer.
The variance component analysis revealed high heritability coupled with high
genetic advance as per cent of mean for all flowering and fruit characters indicatingthat most likely the heritability is due to additive effects making selection effective
based on these characters. Association analysis revealed that plant height, days to
first flowering, number of long styled flowers, fruit diameter, fruit weight and
number of fruits per plant shown significant genotypic correlation and direct effect
showing true association of these characters with fruit yield. Selection based on all
these characters will help to achieve efficient improvement in fruit yield.
The UPGMA clustering of 30 eggplant accessions for qualitative traits
revealed three groups based on anthocyanin pigmentation of plant parts and leaf
prickliness, traits important for stress tolerance.
The genetic diversity analysis based on Mahalanobis D 2 statistics for 22
quantitative characters grouped 30 accessions into eight clusters. The clustering
patern showed the S. melongena accessions collected from North Kerala grouped
under cluster I (22) and cluster III (2). All the five wild accessions were grouped in
five different clusters (III, IV, VI, VII and VIII). The green fruited accessions SM
25 and SM 27 collected from NBPGR were placed in cluster III and cluster V
indicating their distinctness. The character fruit yield per plant, leaf blade width,
number of fruits per plant and leaf blade length hade made major contribution
towards genetic divergence with maximum by fruit yield per plant. The maximum
intra-cluster distance was reported in cluster I, followed by cluster III. The
remaining are solitary clusters. The highest inter- cluster distance was recorded
between solitary clusters V and VIII, V and IV and V and III providing scope for
hybridization between genotypes of these highly divergent cluster especially
involving wild accession SM 30 for fruit and shoot borer resistance.
Selection index involving discriminant functions based on relative economic
importance of various characters showed a combination of four characters (Fruit yield
per plant + Number of long styled flowers + Fruit diameter + Fruit weight) with
maximum relative efficiency. Based on high selection index score involving four
character combination and overall cluster ranking for three yield attributes two green
fruited accessions SM 25 and SM 27 and six purple fruited accessions SM-8, SM-
10, SM-18, SM-20, SM-23 and SM 24 are identified as promising. Among these,the green fruited accession SM 25 had shown very low incidence of fruit and shoot
borer.
Based on selection index score and cluster divergence (high inter-cluster
distance) the SM-27 is identified as promising parent in intra-specific hybrid
involving of SM-27 x SM-25 and inter-specific hybrids involving SM-27 x S.
insanum and SM-27 x S. macrocrpon. These crosses may be attempted in future
breeding program for obtaining progenies superior for yield as well as shoot and fruit
borer and bacterial wilt resistance.