NaCl水培胁迫下棉花苗期耐盐指标筛选与分析

Screening and Analysis of Salt Tolerance Indexes of Cotton Seedling in Hydroponic Culture under Na Cl Stress

对棉花苗期耐盐指标进行筛选与分析,可以简化棉花耐盐性鉴定的程序、缩短耐盐棉花品种的筛选周期。以5个盐耐受程度不同的棉花品种为试材,在水培条件下,比较了不同浓度Na Cl胁迫对棉花幼苗地上部和地下部生长性状的影响,筛选出适宜棉花幼苗期耐盐性鉴定的Na Cl浓度;通过分析该浓度胁迫下参试棉花品种幼苗生长相关性状的差异,筛选出与清水对照差异显著的性状指标,并对其进行主成分分析,筛选出对第1主成分贡献较大的性状指标作为棉花耐盐性评价的适宜指标;依据这些指标,计算参试棉花品种的平均隶属度,评价其耐盐性顺序。结果表明:适宜棉花苗期耐盐性鉴定的Na Cl浓度为150 mmol/L;该胁迫浓度下,除根系长度外,参试棉花品种的其他性状指标(幼苗高度、地上部干重、地下部干重、根系投影面积、根系表面积、根系体积和根系平均直径)均与清水对照存在显著差异,其中,地下部干重、根系投影面积、根系表面积、根系体积和根系平均直径5个地下部因子对第1主成分贡献较大。根据参试棉花品种5个地下部因子的平均隶属度得到其耐盐性顺序为中棉所23>冀棉27>中9807>中S9612>中棉所12,与各品种的耐盐相对成活率顺序一致。幼苗地下部干重、根系投影面积、根系表面积、根系体积和根系平均直径可以作为棉花苗期耐盐性的评价指标。

In order to simplify the identification process of salt tolerance of cotton and shorten the selection cycle of salt tolerant cotton cultivars, the suitable Na Cl concentration and salt tolerance indexes of cotton at seedling stage were screened and analyzed. Five cotton cultivars with different salt tolerance were tested, the effects of different concentrations of Na Cl stress on the growth of ground and underground of cotton seedlings were compared to screen out the appropriate concentration of Na Cl for salt tolerance identification at cotton seedling stage. Under Na Cl stress with the screened concentration, the differences on growth related traits of tested cotton seedlings were analyzed,the indexes which had significant differences with those of control were screened. The principal component analysis was carried out, and the indexes which had larger contribution to the first principal component were appropriate for cotton salt tolerance evaluation. According to these indexes,the average membership degree of the tested cultivars was calculated, and the salt tolerance was evaluated. The results showed that 150 mmol/L was suitable for the determination of salt tolerance. At that concentration, except root system length, there were significant differences in these indexes including seedling height, dry weight of shoot and root, root projection area, root surface area, root volume and average diameter of root system. Five underground factors including the dry weight of root,root projection area,root surface area,root volume and average diameter of root system were contributed to the first principal component. The average membership degree of the tested cotton cultivars was ranked in the order of Zhongmiansuo23Jimian27Zhong9807Zhong S9612Zhongmiansuo12,which was same as the order of relative survival rate.The dry weight of underground, root projection area, root surface area, root volume and average diameter of root system could be used to assess the salt tolerance of cotton seedling.