国槐无性系对NaCl胁迫的生长生理响应及耐盐性综合评价

为揭示国槐无性系对盐渍环境的适应能力,筛选出耐盐速生的优良无性系,以5个国槐无性系盆栽2年生植株为试材,研究不同浓度NaCl(0‰、2‰、4‰、6‰)胁迫对其生长及生理生化指标的影响。采用盆栽方法进行盐胁迫实验,运用主成分分析法对不同处理下各无性系生理指标进行综合评价。结果表明,随NaCl胁迫的增加,5个国槐无性系生长指标（苗高、地径、生物量）均受到了明显抑制,‘华夏’和‘华硕’分别在6‰和4‰处理下表现出相对较强的适应性;叶绿素含量随胁迫的增加而下降,其中下降幅度最小的为‘华夏’和‘华硕’;叶片脯氨酸含量随NaCl胁迫的增加而增加,其中‘华夏’和‘华硕’显著高于其他胁迫条件下的无性系;NaCl胁迫导致叶片细胞膜透性和丙二醛(MDA)含量提高,在4‰NaCl处理下‘华夏’、‘华硕’和卷叶无性系‘嫣红3号’MDA含量低于其他无性系,在6‰NaCl处理下‘华夏’和‘嫣红3号’含量最低;超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)均呈先增大后减小的变化趋势,SOD活性在盐浓度2‰时达到最大值,CAT活性和POD活性在盐浓度4‰时达到最大值,其中‘华夏’的CAT酶活性和POD酶活性在盐浓度6‰时始终高于其他无性系;在6‰NaCl处理下,苗高增长量与生物量、叶绿素、脯氨酸、丙二醛之间,MDA与电导率、SOD、POD之间的相关性达到显著或者极显著相关,表明在对无性系进行耐盐性评价时,综合利用生长指标和生理指标能更好地反映植物受NaCl胁迫的响应。利用主成分分析对5个国槐无性系生长及生理代谢指标进行综合评价,各无性系耐盐性由强到弱为‘华夏’>‘华硕’>‘鲁槐1号’>‘嫣红3号’>无性系564。因此,认为‘华夏’和‘华硕’具有显著耐盐性和速生性,可作为盐碱地造林品种或抗逆育种材料应用。

Clones of Sophora japonica: Growth and Physiological Responses to Stress and Comprehensive Evaluation on Saline-alkaline Tolerance

The paper aims to explore the adaptability of clones of Sophora japonica to saline environment, and select the excellent clones with characteristics of fast-growth and strong saline-alkaline resistance. Five new clones of potted plants were used as test materials to study the effects of different salt concentrations (0‰, 2‰, 4‰, 6‰) on their growth and physiological and biochemical indexes. The salt stress experiment was conducted by pot culture method, and the physiological indexes of the clones under different treatments were evaluated by principal component analysis. The results showed that the growth of above-ground and root were inhibited apparently under salt stress. The two clones ‘Huaxia’ and ‘Huashuo’ showed fast-growth under 4‰ and 6‰ concentration. The chlorophyll content decreased obviously in all clones, and the chlorophyll content of ‘Huaxia’ and ‘Huashuo’ showed the smallest decline under stress. The content of the proline in five clones showed the trend of increasing gradually with the increase of concentration, and that of ‘Huaxia’ and ‘Huashuo’ was significantly higher than the other clones. The cell membrane permeability and MDA content had a steady increase with the increase of concentration, and that of ‘Huaxia’, ‘Huashuo’ and ‘Yanhong No.3’ were significantly lower than others under 4‰ concentration stress, and ‘Huaxia’ and ‘Yanhong No.3’ were the lowest under 6‰ concentration stress. SOD activity, CAT activity and POD activity firstly increased and then decreased, SOD activity reached the maximum at a concentration of 2‰, and CAT activity and POD activity reached the maximum at a concentration of 4‰, and that of ‘Huaxia’ was always higher than the other clones at a concentration of 6‰. Under 6‰ concentration stress, the correlation of MDA with electrical conductivity, SOD, POD, biomass, chlorophyll, proline and malondialdehyde was significant or extremely significant. It indicated that using the growth and physiological indexes to evaluate the salt-resistance of five clones could therefore reflect the response of stress. By principal component analysis, the sequence of salt resistance in five clones was as follows: ‘Huaxia’>‘Huashuo’>‘Luhuai No.1’> ‘Yanhong No.3’> clone 564. Therefore, it is preliminarily considered that ‘Huaxia’ and ‘Huashuo’ have significant saline-alkaline resistance and fast-growing, which could be used as the important testing materials for afforestation in saline area and breeding resource in resistance research.