盐碱胁迫下不同棉花品种植株形态及产量的变化

Changes of Plant Morphology and Yield of Different Cotton Varieties under Saline-alkaline Stress

为明确土壤盐碱化抑制不同棉花品种生长发育情况并揭示不同棉花品种耐盐碱能力的差异,本研究以8个新疆耐盐碱能力不同的棉花品种为试验材料,在大田两个盐碱梯度(高:pH值8.5;低:pH值7.9)下,测定和分析棉花萌发过程中成苗率,初花期与盛铃期的农艺性状(株高、茎粗、果枝台数、蕾花铃、脱落数)、光合特性(净光合速率、气孔导度、胞间CO_(2)浓度、蒸腾速率)及产量。结果发现,高浓度胁迫下棉花的成苗率及株高、茎粗、果枝数、蕾花铃数等形态指标分别比低浓度处理低27.5%、17.54%、6.27%、7.12%和5.51%。盛铃期高浓度下高耐盐碱品种的净光合速率比耐盐碱品种和敏盐碱品种分别高12%和21%;而低浓度下高耐盐碱品种的净光合速率比耐盐碱品种和敏盐碱品种分别低9%和4%。高盐碱胁迫下敏盐碱品种L18的皮棉产量受盐碱抑制程度高达48%,耐盐碱品种仅有3.8%。相关性分析表明:籽棉产量与成苗率、初花期株高、茎粗、气孔导度、胞间CO_(2)浓度、蒸腾速率呈极显著正相关,与盛铃期株高、茎粗、果枝数呈极显著正相关,与光合呈负相关;皮棉产量与成苗率、株高、茎粗、净光合速率、气孔导度、胞间CO_(2)浓度、籽棉产量呈极显著正相关。综上,同一盐碱胁迫下,高耐盐碱品种在初花期与盛铃期均保持较高光合作用,更利于光合产物的积累,能维持棉花正常的生长发育,减少产量损失。

In order to clarify the inhibition of soil salinization on the growth and development of different cotton and reveal the dif⁃ferences in saline-alkali tolerance of different cotton.Eight cotton varieties with different saline-alkali tolerance in Xinjiang were used as experimental materials,and two saline-alkali gradients(high:pH 8.5;low:pH 7.9).The seedling rate during germination,ag⁃ronomic traits(plant height,stem diameter,number of fruit branches,buds,bolls,shedding number),photosynthetic characteris⁃tics(net photosynthetic rate,stomatal conductance,intercellular CO_(2)concentration,transpiration rate)and yield of cotton at early flowering stage and full boll stage were measured and analyzed.The seedling rate,plant height,stem diameter,number of fruit branches,number of buds,flowers and bolls of cotton under high concentration stress were 27.5%,17.54%,6.27%,7.12%and5.51%lower than those under low concentration stress,respectively.The net photosynthetic rate of high saline-alkali tolerant vari⁃eties was 12%and 21%higher than that of saline-alkali tolerant varieties and sensitive saline-alkali varieties under high concentra⁃tion at full boll stage.At low concentrations,the net photosynthetic rate of high saline-alkali tolerant varieties was 9%and 4%lower than that of saline-alkali tolerant varieties and sensitive saline-alkali varieties,respectively.Under high saline-alkali stress,the lint yield of the sensitive saline-alkali variety L18 was inhibited by saline-alkali up to 48%,and that of the saline-alkali tolerant variety was only 3.8%.Correlation analysis showed that seed cotton yield was significantly positively correlated with seedling rate,plant height,stem diameter,stomatal conductance,intercellular CO_(2)concentration and transpiration rate at early flowering stage,and was significantly positively correlated with plant height,stem diameter and fruit branch number at full boll stage,and negatively correlated with photosynthesis.The lint yield was significantly positively correlated with seedling rate,plant height,stem diameter,net photosyn⁃thetic rate,stomatal conductance,intercellular CO_(2)concentration and seed cotton yield.Under the same saline-alkali stress,the high saline-alkali tolerant varieties maintained higher photosynthesis at the early flowering stage and the full boll stage,which was more conducive to the accumulation of photosynthetic products,could maintain the normal growth and development of cotton and reduce the yield loss.