Discriminating phenotypic markers reveal low genetic diversity in spider plant
Traditional vegetables such as spider plant (Cleome gynandra L.) have better nutritional and health benefits. The aim of this study was to determine the extent of genetic diversity of spider plant genotypes based on phenotypic markers and understand its implications in germplasm utilisation in Zimbabwe. Eighteen genotypes collected from across Zimbabwe were evaluated for phenotypic traits. There were no significant differences (P<0.05) in days to flowering, number of branches, fresh and dry mass, pod number, pod length and stem height. Variance components due to error were higher than genotypic variance components for all quantitative traits, resulting in low broad sense heritability estimates, < 39%. Stem colour, pod lining, number of leaf loblets, pod shape and colour, and stem pubescence showed variations. Hierarchical cluster analysis showed 30% dissimilarity among genotypes. At 85% similarity level, there were four clusters and one of the clusters had eleven out of eighteen genotypes. The results showed low genetic diversity of spider plant in the country. Most agronomic traits could have been affected by directional selection arising from farmers preferences. Some selectively neutral descriptor traits such as colour of the stem and pods, leaf loblets number, pod lining and pod shape can be used in characterising and distinguishing spider plant genotypes.
Keywords: Cleome gynandra, descriptor traits, Zimbabwe