Characterization and Estimation of Diversity of Sugarcane (Saccharum officinarum) Genotypes Based on Qualitative Morphological Traits.

Abstract An accurate and extensive study of the qualitative morphological diversity of sugarcane genotypes would allow their identification, conservation and utilization in the sugarcane breeding program. The objectives of the study were to characterize and estimate the morphological diversity of sugarcane genotypes using qualitative traits. Data collected for 16 qualitative characters were analyzed using descriptive statistics and multivariate analysis to assess the overall patterns of morphological variation. Shannon diversity index (H′) was calculated to estimate morphological diversity. The result indicated that the qualitative traits revealed high variability among 144 sugarcane genotypes. The most polymorphic character with the highest Shannon diversity index (H′) was stalk corky patchs. The H′ averaged across all countries for different characters was found to vary from 0.50 to 0.76 with an average of 0.61. The H′ pooled across characters by country of collection ranged from 0.00 to 0.83, with a general average of 0.62. Multivariate cluster analysis has grouped the genotypes into four distinct clusters based on the relatedness and variation for all considered characters. Genotypes with close genetic relationships are grouped in a single cluster. The clustering pattern of the genotypes elucidated that genotypes originating from the same geographic locations did not form a single cluster. This shows that geographic diversity has not associated with genetic diversity, which may be due to the continuous exchange of genetic material among countries. Finally, we concluded that the qualitative morphological traits evaluated in this study could be used for varietal identification, maintaining genetic diversity and managing sugarcane germplasm.