【目的】研究干旱胁迫对气孔导度(Gs)、PSⅡ原初光能转化效率(Fv/Fm)、叶片伸长速率(leaf elongation,LE)和叶片相对含水量(relative water content,RWC)4个甘蔗生理指标遗传变异的影响,为其在甘蔗育种程序早期阶段的应用提供参考。【方法】采用裂区设计,以自然干旱和人工灌溉为主区,不同甘蔗基因型为副区,在云南省红河州开远市和玉溪市元江县2个试验点先后对22个和18个甘蔗基因型同时开展田间试验,主要在2个生长季甘蔗拔节前期先后13次、18次、15次和10次分别对4个生理指标Gs、Fv/Fm、LE、RWC进行测量。采用软件GenStat计算各指标各次测量的遗传方差分量(σ_g~2)和环境方差分量(σ_e~2),并计算广义遗传力(h_b~2),采用SAS9.1对每次测量干旱和灌溉处理下获得遗传方法分量和广义遗传力进行成对t测验。【结果】四项生理指标受干旱影响极显著,13次Gs、18次Fv/Fm、15次LE和10次RWC处理间差异均为极显著。在干旱和灌溉处理下,13次Gs基因型间分别10次和11次差异显著,广义遗传力范围分别为0.19-0.68和0.19-0.82,13次平均分别为0.49和0.53,灌溉条件下的遗传方差显著高于干旱胁迫下的遗传方差;18次Fv/Fm基因型间分别17次和16次差异显著,广义遗传力范围分别为0.26-0.83和0.16-0.85,平均值分别为0.64和0.58,干旱条件下的遗传方差极显著高于灌溉条件下的遗传方差;15次LE基因型间分别14次和10次差异显著,广义遗传力范围分别为0.09—0.89和0.09—0.81,平均值分别为0.58和0.50,干旱处理下平均遗传方差和遗传力较高;10次RWC基因型间分别8次和6次差异显著,广义遗传力范围分别为0.10-0.76和0.16-0.77,平均值分别为0.57和0.47,干旱条件下平均遗传方差和广义遗传力较高。总之,除Gs,其他3个指标在干旱条件下获得广义遗传力均高于灌溉条件下的广义遗传力。【结论】干旱胁迫影响Gs、Fv/Fm、LE和RWC的遗传变异和广义遗传力,在灌溉条件下测量Gs和在干旱条件下测量其他3个指标更易获得较高的遗传变异和广义遗传力,但所有4个生理指标均能在灌溉条件下获得较高的广义遗传力。 【Objective】 The objective of this study was to investigate the effects of drought stress on the stomatal conductance (Gs), PS Ⅱ primary light energy conversion efficiency (Fv / Fm), leaf elongation (LE) and relative water content (RWC) The effects of sugarcane physiological indices on genetic variation were analyzed for reference in the early stages of sugarcane breeding program. 【Method】 With split-plot design, natural drought and artificial irrigation were the main areas, and different sugarcane genotypes were sub-districts. Two pilot sites in Kaiyuan, Honghe Prefecture, Yunnan Province and Yuanjiang County, Yuxi City were allocated to 22 and 18 The sugarcane genotypes were also tested in the field at the same time. The physiological indexes of Gs, Fv / Fm, LE and RWC were measured 13 times, 18 times, 15 times and 10 times respectively in the early growing season. The genetic variance component (σ_g ~ 2) and the environmental variance component (σ_e ~ 2) of each measurement were calculated by software GenStat, and the generalized heritability (h_b ~ 2) was calculated. For each measurement of drought and irrigation The genetic method components and the generalized heritability were processed for paired t tests. 【Result】 The four physiological indices were significantly affected by drought. The differences of 13 Gs, 18 Fv / Fm, 15 LEs and 10 RWC treatments were all significant. Under drought and irrigation treatments, the 13 Gs genotypes were significantly different between 10 and 11 times, with the generalized heritability ranged from 0.19 to 0.68 and 0.19 to 0.82, respectively, with a mean of 0.49 and 0.53, respectively, under the irrigation condition The variance was significantly higher than that under drought stress. The 18 Fv / Fm genotypes were significantly different between 17th and 16th times, with the generalized heritabilities ranging from 0.26 to 0.83 and 0.16 to 0.85, respectively, with mean values ​​of 0.64 and 0.58, respectively. The genetic variances under drought conditions were significantly higher than those under irrigation conditions. The differences between 15 LE genotypes were significant at 14th and 10th, respectively, and the general heritabilities ranged from 0.09 to 0.89 and 0.09 to 0.81, respectively 0.58 and 0.50, respectively. The mean genetic variance and heritability of the RWC genotypes were higher in the drought treatment. The differences among the 10 RWC genotypes were significant at the 8th and 6th times, with the general heritabilities ranging from 0.10 to 0.76 and 0.16 to 0.77, respectively, with mean values ​​of 0.57 And 0.47, the average genetic variance and broad heritability in drought conditions were higher. In short, except for Gs, the other three indicators of generalized heritability obtained under drought conditions were higher than the generalized heritability under irrigation conditions. 【Conclusion】 The results showed that drought stress affected the genetic variation and general heritability of Gs, Fv / Fm, LE and RWC. It was easier to obtain higher genetic variation and general heritability by measuring Gs under irrigation and measuring the other three indexes under drought conditions , But all four physiological indicators can obtain a higher general heritability under irrigation conditions.