Genetic Study of Some Agronomic Characters in Eggplant (Solanum melongena L.).

Abstract

Eggplant breeding has not been done intensively despite available high genetic diversity, and increased public interest, so it is an opportunity and a challenge to be able to assemble a variety with proper breeding methods. Evaluation on genetic diversity, heritability and correlations between characters in eggplant (Solanum melongena L.) conducted in Kediri, East Java, in January - August 2012 used 30 genotypes collection of PT. BISI International Tbk from Indonesia (8 genotypes), Philippines (5 genotypes), 15 genotypes from China and India (2 genotypes), arranged in Randomized Complete Block Design with 3 replications. The results showed that there was phenotypic variability among 30 eggplant genotypes derived from several source populations. Genotypes from India showed different characters in the age of flowering, fruit length, fruit diameter, fruit weight and number of fruits per plant. There were characters which had high broad sense heritability with high genetic advance i.e. fruit length (92.84%, 43.3%), fruit diameter (68.71%, 45.12%), fruit weight (86.18%, 52.77%), and the number of fruits per plant (62.74%, 47.77%). There were 14 positive and 8 negative significant correlation coefficiens between the main characters. Based on principal component analysis (PCA), combination of PCA I and PCA III gave 42.92% of variability, it separated genotypes into 3 groups, i.e. BEPA05 in group I, BEPE97 in group II and 28 genotypes in group III. . Full diallel cross by Griffing method I made on 8 genotypes (BEP 01, BEP04, BEP 06, BEP 08, BEP 10, BEP11, BEP 12) to test the general combining ability, specific combining ability and genetic parameter. The experiments were performed used 64 genotypes consisted of 28 F1, 28 F1R and 8 parents, used Randomized Complete Block Design with 3 replications in November 2012 - April 2013. Characters of flowering age, harvesting age and fruit weight per plant was affected by the action of a dominant gene because it had specific combining ability value (SCA) higher than the general combining ability (GCA). Plant height, fruit length, fruit diameter, fruit hardness, weight per fruit and number of fruit per plant characters expression was influenced by additive gene action because it had GCA higher than SCA. BEP 04 genotypes have relatively more consistent with SCA and GCA values higher than other genotypes. No interaction of genes on the performance of the characters because the value of b (Wr, Vr) were not significantly different from 1 except fruit weight and number of fruit per plant. The genes distribution for the traits studied unequal on each parents. Fruit length and fruit hardness were controlled by at least one group of genes. Fruit diameter, weight per fruit and number of fruit per plant at least two groups of genes, flowering and plant height were controlled by at least three groups of genes. Harvesting was controlled by at least four groups of genes and the weight of fruit per plant was controlled by at least 5 groups of genes. Broad sense heritability of all the characters were high (h2BS > 50%). All characters had high heritability narrow sense except days to flowering (27%), harvesting (49%), and weight of fruit per plant (44%) had a narrow sense heritability of the group are medium. Evaluation of hybrid from diallel cross conducted to determine hybrid performance compare to commercial hybrids as check varieties. Experiments used 64 hybrids eggplant consisting of 56 hybrid F1 and F1R, 6 commercial hybrid varieties of purple eggplant and 2 green eggplant of commercial varieties, performed using Randomized Complete Block Design with 3 replications in November 2012 - April 2013. The results showed some hybrids had exceeded character value or the same as the best check variety. So potentially for further testing to determine the adaptation and consumer preferences. BEP 05 x BEP 04 (24.57), BEP 01 x BEP 04 (27.17) had earlier flowering and harvesting age equal to the best check variety. Hybrids that had a shorter plant height than the check variety was BEP 04 x BEP 05. BEP 04 produced several hybrids with fruit firmness higher than check varieties. Hybrid BEP BEP 01 x 06, BEP 06 x BEP 01, BEP 06 x BEP 04, BEP 06 x BEP 05 potential to be developed because it had weight per plant which were not significantly different from best commercial variety.