Field Evaluation of New Promising Sugarcane Cultivars for Cold Tolerance in Guangxi, China

Abstract

Sugarcane often suffers from low-temperature stress in Guangxi, China. In this study, the cold tolerance potential of 20 new sugarcane varieties was evaluated on the basis of chlorophyll content (Chl), chlorophyll fluorescence parameters, plasma membrane permeability (PMP) and malondialdehyde (MDA) content, and visual scoring. The study was conducted at the experimental field of Fushui Field Station of Guangxi University. Following the period of cold stress, the Chl of sugarcane varieties decreased, while PMP and MDA contents increased. Moreover, the chlorophyll fluorescence parameters (Fo, Fm, Fv/Fm, Fv/Fo) also showed changes as a result of cold stress. However, these fluctuations significantly varied among different varieties. Likewise, the cold tolerance index (CTI) of the sugarcane varieties ranged from 0.03 to 0.76 depicting a great variability in the cold stress tolerance of varieties under evaluation. The correlation analysis of physiological indicators with cold tolerance parameters revealed that CTI was positively correlated with PMP and MDA and negatively correlated with Chl and its fluorescence parameters. Based on overall evaluation, eight varieties, viz. GUC44, CP88-1762, CP96-1257, GUC50, GX13-4201, GX13-4222, CP97-2730, and CP05-1762, were identified as a highly cold tolerant, while seven varieties were categorized as mild tolerant, five as susceptible, two as mild highly tolerant, and two as mild susceptible. This study offers an insight into physiological response of sugarcane against cold stress and an all-inclusive approach to screen sugarcane genotypes against this widespread issue of concern. Moreover, it is expected that this study will provide some promising sugarcane germplasm resources with better cold stress tolerance.