Genetic Diversity of Tiger Nuts (Cyperus esculentus L.) Grown in Ghana Based on Morpho-Descriptors and SSR Markers

Purpose: Limited information is available on the diversity of tiger nuts in Ghana for improvement. Therefore, evaluating the genetic diversity via the use of morphological descriptors and molecular markers (SSR) should generate substantial evidence to reveal the variability among and within the crop.
Research Method: Forty-two (42) accessions of Cyperus esculentus Lativum were collected from major tiger nut cultivation areas (phytogeographic zones) in Ghana and evaluated using 11 morpho-descriptors and 9 SSR markers to assess variability among and within the tiger nut accessions and underlined causes.
Findings: Significant differences were observed among the accessions in terms of percentage inflorescence (p≤0.01), distance of the last tiller from the main plant (p≤0.05) and the number of tubers per stand (p≤0.05). Unweighted Pair Group Method with Arithmetic Mean (UPGMA) cluster analysis grouped the accessions into seven clusters including one large heterogenous cluster at 0.94 Euclidean distance, and genetic distance ranged from 0.8 to 1.00. The SSR profiling revealed 141 alleles across 41 of the accessions used for the molecular study with a mean PIC value of 0.78 ± 0.15 and mean observed heterozygosity of 0.12 ± 0.16 coupled with four heterotic UPGMA cluster groupings including one large heterogenous cluster at a similarity coefficient of 0.88. The high variability among the accessions for some of the traits, and the low genetic variability within the accessions in cluster groupings for both morphological and SSR evaluations suggested some level of admixture of genes over years of cultivation.
Originality/ Value: The current study has identified some accessions for improvement. Also, it has contributed to knowing some SSR markers that would amplify tiger nuts for future molecular study for breeding enhancement.