DOI: 10.36347/sajb.2019.v07i09.002

Pages: 361-367

For an efficient and sustainable development of agriculture, it is necessary to obtain plant material which can face new environmental constraints due to climate change. The present study analysed the genetic determinism of proline content, an amino acid, marker for stress resistance, and its correlation with agro-morphological characteristics in S. melongena and S. insanum. Plant material consists of eggplant accessions MEL1 and MEL5, S. insanum accession INS1, two interspecific F1 hybrid progenies and two backcross progenies. Proline content was estimated using young leaves collected in the morning. Genetic determinism of proline content was analysed based on the segregation pattern in BC1 progenies. Phenotypic and genotypic coefficients of correlation between proline content and 16 agro-morphological traits were estimated. Proline content had a continuous and transgressive distribution in BC1 progenies, "(MEL1 x INS1) x MEL1" and "(MEL5 x INS1) x MEL5", which suggests that it has a polygenetic control. In addition, the gap between genotypic and phenotypic coefficients of variation was small whereas the narrow sense heritability was moderate; indicating that non-additive genetic effects such as dominance and / or epistasis effects may be involved in the expression of proline content. High negative correlations were observed between proline content and fruit characteristics, suggesting that they could be used as phenotypic markers for assessing the ability of eggplant genotypes to produce larger or smaller quantities of proline. These data also show that any eggplant breeding programme aiming to increase drought tolerance by increasing proline content in the leaves may lead to the selection of varieties with small fruits.