An Assessment of Genetic Diversity of Yield-Related Traits of Saccharum spontaneum from Yunnan Province, China

Saccharum spontaneum L. is an important wild used parent for sugarcane breeding, which can improve variety yield, ratoon ability and resistance to biotic and abiotic stress. In order to illustrate the genetic diversity of yield-related traits within a collection of S. spontaneum from Yunnan province, China, 222 clones from six geographic regions of Yunnan were screened for five yield-related traits. The results showed that: (1) the coefficient of variation (CV) of five yield-related traits ranged from 20.39 to 77.06%, of which the stalk weight exhibited the highest genetic variation with the highest CV value (77.06%), followed by the tillering rate with a CV value of 38.33%. The clones from the northwestern region of Yunnan exhibited the highest genetic variation, with an average CV value of 39.03%, followed by clones from the southwestern and southern regions; (2) the elevation and latitude of the locations from where the clones were collected had significant negative correlations with stalk height, stalk diameter and stalk weight (p < 0.01), but there was a significant positive correlation between latitude and tillering rate; (3) among six populations, there was no obvious genetic divergence because of a small divergence coefficient (Gst = 5.18%) and high gene flow (Nm = 9.1587); and (4) based on the UPGMA cluster analysis of these clones, three groups with obvious difference in four traits were obtained. Finally, the top 15 ranked clones per trait were listed in the paper for innovation utilization. The results from this study will aid in the selection of high biomass clones as wild parents for improving variety yield potential and can provide direction for the collection and management plan of S. spontaneum resources of Yunnan.