Characterisation and Widening of the Genetic Base of Tiger Nut (Cyperus Esculentus L.) by Chemical Mutagenesis

Abstract

Limited information exists regarding the diversity of tiger nuts (Cyperus esculentus L.) in Ghana, hindering potential improvements. To address this gap, an assessment of genetic diversity was conducted using 11 morpho-descriptors and nine simple sequence repeat (SSR) markers to explore variability among and within the accessions to provide valuable insights for further breeding through mutagenesis. A total of 42 accessions were collected from major tiger nut growing areas in Ghana and these were planted in the field using a randomized complete block design (RCBD) with 3 replications. The results from the field characterization showed significant differences among the accessions for some traits studied. The use of SSR markers demonstrated high mean polymorphism of 0.78. UPGMA cluster analyses of both morphological and molecular data indicated low genetic variability within the accessions. Four high-yielding accessions were identified for potential improvement through mutagenesis. Subsequently, 400 tubers of the four genotypes (two brown and two black tuber-producing) underwent treatment with ethyl methanesulfonate (EMS) and colchicine at various concentrations. Analysis of quantitative data revealed LD50 and RD50 values for mass treatmeant of tiger nut tubers with the mutagens. Subsequently, 600 tubers of the four selected genotypes were mass-treated with EMS and colchicine mutagens following the LD50 and RD50 values determined, and were field-planted for M1V1 to M1V4 generations. Twenty-one mutants have beeen identified for breeding enhancement and possible varietal release.