不同品种(品系)棉花对盐胁迫的生理响应及耐盐性评价

Physiological responses of different cotton cultivars(strains)to salt stress and salt tolerance evaluation

以耐盐棉花品种中H177、耐盐棉花品系中J0710与盐敏感棉花品种新陆早74、盐敏感棉花品种中J0102为试验材料,通过田间微区控制试验,研究土壤盐胁迫对不同棉花品种(品系)生理生化特性的影响并开展相应的耐盐性评价。结果表明,耐盐棉花品种(品系)的叶片脯氨酸含量显著高于盐敏感棉花品种(P<0.05),前者为后者的1.31~4.14倍,但耐盐棉花品种(品系)的丙二醛含量显著低于盐敏感棉花品种(P<0.05),前者仅为后者的52.73%~66.26%;耐盐棉花品种(品系)的叶片SPAD值和光合参数(净光合速率、气孔导度、胞间CO2浓度、蒸腾速率)明显大于盐敏感棉花品种;耐盐棉花品种(品系)茎中Na^+含量、根中Na^+含量、茎中K^+含量、地上部分的K^+/Na^+整体上高于盐敏感棉花品种。耐盐棉花品种(品系)能保持较高的光合能力,并能维持K^+/Na^+平衡,同时能够减缓丙二醛含量的增加,增强棉株的耐盐性。通过主成分分析和灰色关联度分析得出,对棉花进行耐盐性评价时可将光合指标、SPAD值和抗氧化酶活性作为重要的鉴定指标。由评价结果得出,在供试的棉花品种(品系)中,中H177苗期的耐盐性较好。

Salt-tolerant cotton cultivar Zhong H177,strain Zhong J0710 and salt-sensitive Xinluzao 74,Zhong J0102 were used as the test materials by field micro-control experiments to study the effects of soil salinity stress on physiological and biochemical characteristics of different cotton cultivars(strains),and related salt tolerance evaluation was carried out.The results showed that proline content in the leaves of salt-tolerant cotton cultivars was significantly higher than that of salt-sensitive cotton cultivars(the former was 1.31 to 4.14 times as much as the later),but malondialdehyde content in the leaves of salt-tolerant cotton cultivars(strains)was significantly lower than that of salt-sensitive cotton cultivars(the former was only 52.73%to 66.26%of the later).The soil and plant analyzer development(SPAD)value and photosynthetic parameters(net photosynthesis rate,stomatal conductance,intercellular CO2 concentration,transpiration rate)of salt-tolerant cotton cultivars(strains)leaves were significantly higher than those of salt-sensitive cotton cultivars.The Na^+content in stem,Na^+content in root,K^+content in stem and K^+/Na^+in aboveground parts of salt-tolerant cotton cultivars(strains)were higher than those of salt-sensitive cotton cultivars.The salt-tolerant cotton cultivars(strains)could maintain high photosynthetic capacity and K^+/Na^+balance,slow down the increase of malondialdehyde content and enhance salt tolerance of cottons.The results of principal component analysis and grey relational grade analysis showed that photosynthetic indices,SPAD values and antioxidant enzyme activities in salt tolerance evaluation of cottons could be used as important identification indices.According to the evaluation results,Zhong H177 shows good salt tolerance at seedling stage among the tested cotton cultivars(strains).