干旱胁迫对甘蔗生长生理的影响及品种抗旱性评价

[目的]综合分析甘蔗不同时期及品种的抗旱性差别,为甘蔗抗旱性评价和品种选育提供依据.[方法]以GT28、GT21及ROC22 3个甘蔗品种为材料,在桶栽自然干旱胁迫条件下,测定株高和其他7个生理生化指标,并采用模糊数学隶属函数法综合评价供试品种的抗旱性.[结果]在反复干旱胁迫处理下,不同甘蔗品种的生长势、叶片水势及叶绿素含量均有不同程度降低,叶片脯氨酸和丙二醛含量升高,叶片细胞质膜透性增大;生长势、叶片水势、脯氨酸含量以及POD活性在苗期变化幅度较大,而丙二醛含量、叶片细胞质膜透性、可溶性蛋白和叶绿素含量在伸长期变化较明显.不同品种中,以GT21叶片水势、丙二醛和可溶性蛋白含量、叶绿素含量相对较高,细胞质膜透性、游离脯氨酸和POD活性相对较低,而ROC22株高、细胞质膜透性、脯氨酸含量、POD活性较高,丙二醛和可溶性蛋白稍低于GT21,叶片水势较低.供试3个甘蔗品种的整体抗旱性强弱的排序为GT21>ROC22>GT28.[结论]干旱胁迫下不同甘蔗品种间的农艺性状及生理指标变化差异明显,苗期与伸长期反复两次干旱胁迫处理没有表现出一致明显的累积影响效应,应用隶属函数法能更加准确全面评价甘蔗品种的抗旱特性.

Impact of drought stress on sugarcane growth physiology and evaluation on drought resistance of sugarcane cultivars

[Objective]The present study was conducted to investigate the differences of drought resistance in different sugarcane cultivars at different growth stages to provide references for drought resistance evaluation and sugarcane breeding. [Method]Three sugarcane cultivars viz., GT28, GT21 and ROC22,planted in buckets,were used as test materials. Plant height and seven other indexes were determined under natural drought stress, and drought resistance was evaluated using subordinate function in fuzzy mathematics. [Result]Under repeated drought stress, growth vigor of sugarcane plant slowed down, water potential and chlorophyll content in leaves were reduced, and cytoplasm membrane permeability and content of proline and malondialdehyde in leaves increased. For different growth stages, sugarcane growth vigor, water potential, proline content and peroxidase (POD) activity in sugarcane leaves changed more significantly at seedling stage, while malondialdehyde content, leaf cytoplasmic membrane permeability and content of soluble protein and chlorophyll in leaves changed more obviously at elongation stage. Among different sugarcane cultivars, GT21 had relative higher contents of water potential, malondialdehyde, soluble protein, and chlorophyll and lower cytoplasm membrane permeability, free proline content, and POD activity; ROC22 had higher plant height, the cytoplasm membrane permeability, proline content, and POD activity; however it had lower water potential, malondialdehyde, and soluble protein content in leaves compared to those of GT21. The overall drought resistance of the three sugarcane cultivars were as followed: GT21 > ROC22> GT28. [Conclusion]Agronomic traits and physiological indexes showed significant differences in different sugarcane varieties under drought stress, but no obviously consistant and accumulative effects of repeated drought stress (at seedling and elongating stages) were found. Subordinate function method could more accurately and comprehensively evaluate the drought resistance of sugarcane cultivars.