摘要
为研究白榆苗木在盐碱胁迫下的生理指标变化规律,筛选有效评价指标,并对家系进行耐盐碱能力评价,以9个白榆家系的一年生苗为材料,在土壤盐碱含量梯度控制试验条件下,测定了不同家系苗木的生理指标与受害情况。结果表明:苗木耐盐碱能力在家系间不同,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、光系统Ⅱ(PSⅡ)内稟光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/F0)与土壤盐碱含量的变化协同性较好,且在家系间有显著差异,其中Fv/Fm、Fv/F0与土壤盐碱含量梯度无交互作用,Pn、Gs、Tr对盐碱胁迫反应更敏感,两类指标各具优点,均是评价白榆家系耐盐碱的有效指标;水分利用效率(WUE)可作一般性参考指标。根据光合和荧光有效指标以及苗木受害情况对白榆家系耐盐碱能力有相似评价效果,用3类指标综合评价显示:家系2、6、9苗木耐盐碱;家系1、4、5苗木耐盐碱胁迫较弱;家系3、7、8对盐碱胁迫较敏感,但对中低强度胁迫表现出一定抗耐性。多数家系苗木在土壤盐碱含量为0.6%时指标增大,说明白榆可耐土壤盐碱含量为0.6%的胁迫强度。相关性分析表明,有效指标间存在显著或极显著相关。利用生理指标评选有较高耐盐碱能力的白榆家系是可行的。
To evaluate alkaline-salt tolerance of one-year-old Ulmus pumila seedlings,ten physiological indices and three adaptability indices were investigated under simulation control test with different alkaline-salt content levels.Results showed that among these physiological indices,the photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),optimal photochemical efficiency(Fv/Fm) and potential activity(Fv/F0) of photosystem II were sensitively response to alkaline-salt stress in soil for seedlings,and there were significant variations between tested families.These five indices are valuable for family evaluation.Two indices,Fv/Fm and Fv/F0,have no significant interaction effects between family and soil alkaline-salt content level,which means that they can better reflect the tolerance response for all tested families and are the first choice.While water use efficiency(WUE) only acts as a referenced index.The results of family evaluation based on the effective photosynthesis and fluorescence indices and damaged symptom conditions were similar,the integrated evaluation with three types of indices showed that:the families 2,6 and 9 were among the most tolerant ones;while families 1,4 and 5 were weaker and the families 3,7 and 8 were sensitive to alkaline-salt stress,but were tolerant at certain degree to slight and moderate stress.The 0.6% of alkaline-salt content in soil should be the point to limit seedling growth and adaptation in most tested families of U.pumila.The significant positive correlative coefficients among the five indices mentioned above have suggested that one index could be referenced to others.In conclusion,selection of family for higher tolerance to alkaline-salt stress in seedlings by physiological indices is feasible.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2010年第5期74-81,共8页
Journal of Beijing Forestry University
基金
"十一五"国家科技支撑计划项目(2006BAD030103)
关键词
白榆
盐碱胁迫
指标
家系变异
耐盐碱评价
Ulmus pumila
alkaline-salt stress
index
family variation
evaluation of alkaline-salt tolerance