滨海盐碱胁迫下白蜡无性系生长及生理特性的响应

Responses of Growth and Physiological Characteristics of Fraxinus Clones to Coastal Saline-Alkaline Stress

为筛选白蜡耐盐速生优良无性系,在滨海盐碱环境胁迫下,以国内收集的42个白蜡种质资源无性系为研究对象,利用相关性和主成分分析法对42个无性系干鲜比、株高、地径以及超氧化物歧化酶(SOD)、细胞膜透性、叶绿素、过氧化物酶(POD)、丙二醛(MDA)生理代谢等指标进行遗传变异分析和综合评价。结果表明:42个无性系8个指标之间存在一定程度的差异,其中过氧化物酶(POD)变异系数最大,为64.33%,变异幅度25.00~458.30 U/(g·min);其次为丙二醛(MDA),变异系数为49.52%,变幅为0.50~7.08 umol/kg;再次为叶绿素和地径,变异系数分别为18.92%和18.56%,变幅分别为1.46~4.26 mg/g和1.15~2.78 cm;相关性分析结果表明,滨海盐碱胁迫下苗木干鲜比、株高和地径与各生理指标之间的相关性均达显著或极显著相关,说明利用生长指标和生理指标对无性系耐盐性进行综合评价,能反映滨海盐碱胁迫后的响应;利用主成分分析法对42份白蜡种质资源无性系综合得分及排名得知,各无性系耐盐碱性由强到弱前10位依次为‘盐3’>‘LC13’>‘济20’>‘R7-2’>‘盐2’>‘环翠3号’>‘胶南11’>‘白蜡4-2’>‘白蜡2’>‘DT21’。因此,初步认为上述10个无性系具有显著速生性和耐盐碱性,可作为盐渍立地造林或抗逆育种的重要应用材料。

In order to screen fine salt-tolerant and fast-growing Fraxinus clones,42 Fraxinus clones collected in China were studied under coastal saline-alkaline stress.The genetic variation of dry/fresh ratio,plant height,ground diameter,superoxide dismutase(SOD),cell membrane permeability,chlorophyll,peroxidase(POD),malondialdehyde(MDA)physiological metabolism of the 42 clones were analyzed and evaluated by using the correlation and principal component analysis.The results showed that there were some differences among 8 indexes of the 42 clones.The variation coefficient of peroxidase(POD)was the largest(64.33%),and the range of variation was 25.00-458.30 U/(g·min).The variation coefficient of malondialdehyde(MDA)was the second,with a variation coefficient of 49.52%and a variation range of 0.50-7.08μmol/kg.In terms of chlorophyll and ground diameter,the coefficient of variation was 18.92%and 18.56%,respectively,and the variation range was 1.46-4.26 mg/g and 1.15-2.78 cm,respectively.The results of correlation analysis showed that the dry/fresh ratio,plant height and ground diameter of seedlings under saline-alkaline stress were significantly or extremely and significantly correlated with various physiological indexes,indicating that the comprehensive evaluation of the salt-tolerance of Fraxinus clones by using growth indexes and physiological indexes could better reflect the response of Fraxinus clones to saline-alkaline stress in coastal areas.According to the comprehensive score and ranking of the 42 clones of Fraxinus germplasm resources by principal component analysis,the top 10 clones with saline-alkaline tolerance from strong to weak were‘Yan 3’>‘LC13’>‘Ji 20’>‘R7-2’>‘Yan 2’>‘Huancui 3’>‘Jiaonan 11’>‘Baila 4-2’and‘Baila 2’>‘DT21’.Therefore,it is preliminarily concluded that the above 10 clones have significantly fast growth and saline-alkaline tolerance,and could be used as important materials for site afforestation or stress tolerance breeding.