Abstract

Introduction: Mutation breeding is the process of exposing seeds to chemicals or radiation in order to generate mutants with desirable traits. Aim: This study is aimed at assessing the genetic variability among mutant lines of tomato (Solanum lycopersicum L.) generated from a variety of tomato (Roma VF) using two different chemo-mutagens. Materials and Method: The collected seeds were exposed to different concentrations of Sodium azide and Colchicine with varied period of exposure. The seeds were planted and selected 49 positive mutant lines were assessed for morphological genetic variability and yield. 18 mutant lines that produced fruits were tagged and selected. The fruits of the selected mutants were harvested and the seeds (M2 seeds) were subsequently planted for divergence analysis. Ten quantitative characters and twenty qualitative characters were scored using IPGRI standard tomato descriptor. The potted experiment was laid out in the Green House, using Randomized Block Design (RBD) with three replications. Result: The results of this study revealed a high genetic divergence among the mutant lines in both quantitative and qualitative characters. There was significant LSD (0.05) for Germination percentage (7.66), Plant height at maturity (7.05) and Number of leaves at maturity (4.56). The yield (fresh fruit weight) varied significantly, ranging from 10.00g for LeMT29 to 319.70g for LeMT7 respectively. Fruit and plant qualitative characters equally exhibit variation. Conclusion: These observations suggest the existence of genetic variability among the different mutant tomato lines. Further selection and field trials is recommended to identify suitable and desirable lines for possible variety release. To Keywords: Mutant, Tomato, Colchicine, Sodium azide, genetic variability.

Keywords: Mutant, Tomato, Colchicine, Sodium azide, and Genetic variability