干旱对特早熟陆地棉光合特性与产量的影响

目的]为了解特早熟棉花光合特性及产量性状对干旱的适应性,以及光合特性与产量性状之间的关系.方法]在正常灌溉和水分胁迫下,采用Li-6400光合测定系统对60个棉花种质资源功能叶片光合参数以及产量性状进行了研究.结果]光合速率在水分胁迫下普遍有所下降,光合速率(Pn)在蕾期和花期变异较小,苗期和铃期的光合速率变异性较大.籽棉产量、单株铃数、皮棉产量对水分较为敏感,而单铃重和衣分变化不大;正常灌水时棉花籽棉产量性状与光合参数间无显著的关系,而干旱时,棉花籽棉产量与光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和气孔导度(Gs)存在极显著的正相关.聚类分析表明正常灌溉和水分胁迫下的结果不同.结论]在选育棉花抗旱品种时,将棉花资源材料在干旱条件下进行选择为好,可将干旱时花铃期光合速率作为抗旱的主要参数.

Effects of Drought on Photosynthetic Characteristies and Yield of Early Maturing Upland Cotton

Objective] The aim of this text was mainly to observe the effects of drought on photosynthetic characters and yield of early maturing upland cotton.Method]The changes of photosynthetic parameter and productivity traits in the 60 cotton varieties under well-irrigation and water-limited conditions were measured by the Li-6400 portable photosynthesis system during the growing stage.Result] The results showed that photosynthetic parameter were declined,photosynthetic rate (Pn) were changed little in bud and flower period,they were changed greatly in seedling and boll period.Seed cotton yield (SCY),boll per plant(BP),lint yield(LY) were sensitive to drought,however boll weight (BW) and lint proportion(LP) were not affected by water stress.Photosynthetic parameter were not significantly correlated with productivity traits in well-water,but they were significantly correlated with productivity traits.The cluster analysis showed that there were different resutts when normal irrigation and water otress were conducted.Conclusion]When breeding cotton varicties with drought resistance,it is better to select cotton resources nnder drought conditions.