Abstract: Through factor analysis and grey correlative degree analysis, this paper studied the relationships of sugarcane leaf relative water content (RWC), membrane lipid peroxidation metabolism, active oxygen metabolism, photosynthesis, and stalk yield with drought resistance of sugarcane. The results suggested that under drought stress, the plasma membrane permeability (PMP) and malondialdehyde (MDA) content were markedly increased, while RWC, superoxide dismutase (SOD) activity, chlorophyll (Chl) content, PSⅡ photochemical efficiency (F_v/F_m), PSⅡ potential activity (F_v/F_o), variable fluorescence quenching rate (ΔF_v/F_o), efficiency of potential quantum conversion (ΔF_v/F_t), and single stalk weight (SSW) were remarkably decreased. The correlation of SSW with test indexes was decreased in the order of PMP, SOD activity, MDA content, RWC, F_v/F_o, F_v/F_m, Chl content, ΔF_v/F_o and ΔF_v/F_t. Through factor analysis, the test indexes were divided into four common factors, among which, the indexes of photosynthesis played important roles in the first factor, RWC and the indexes of active oxygen metabolism dominated in the second factor, while SSW and Chl content played primary roles in the third and fourth factor, respectively. The grey correlative degree of SSW with other indexes was in the rank of F_v/F_m, PMP, F_v/F_o, RWC, MDA content, SOD activity, ΔF_v/F_t, Chl content, and ΔF_v/F_o.

Key words: Thuidium cymbifolium, Chrysocladium retrorsum, Photosynthesis, Light response, Temperature response, Water relation