摘要
以新疆筛选的5个种源胡杨(Populus euphratica)种子为材料,置于不同NaCl浓度梯度(25、50、150、250、300mmol·L^(-1))下进行种子萌发试验,并测量分析不同种源地气候与土壤生态因子,探讨盐胁迫下不同种源胡杨种子的发芽特征及其与生态因子之间的关系,同时讨论不同种源胡杨比叶面积(SLA)与环境适应性之间的关系。结果表明,在NaCl胁迫下,5个种源胡杨种子的平均发芽率、发芽指数及发芽势间有显著差异(P<0.05),其中种源D(甘家湖种源)种子在盐胁迫下的平均发芽率(19.19%)、发芽指数(4.14)及发芽势(15.57%)显著>其他4个种源种子(发芽率12%~15%,发芽指数2~2.7,发芽势8%~11%,P<0.05);在25mmol·L^(-1)浓度的NaCl胁迫下,除种源E外,其他4个种源种子的发芽率相比对照处理(0mmol·L^(-1))增大11%~35%,相对盐害率均显示负值(P<0.05),而在盐浓度为50 mmol·L^(-1)时,其种子萌发开始受到明显抑制(P<0.05);种源E的SLA值最低而种源D的最高,其中间有显著性差异(P<0.05)。不同种源胡杨种子的发芽率与采样地年平均降水量、土壤40cm的pH值间有显著正相关关系(P<0.05)。以上结果表明,低浓度盐对胡杨种子萌发有一定的促进作用,而高盐浓度下,种子萌发受到明显抑制;145~192mmol·L^(-1)浓度为胡杨种子萌发的耐盐临界浓度。研究结果为自然界现有的变异中筛选具较耐盐的胡杨种子和选育耐盐种质材料提供一定的科学依据。
Populus euphratica seeds were collected from 5 different provenances in Xinjiang, and the seed germination characteristics were tested under NaC1 solution with different concentrations （25,50,150,250, and 300 mmol·L^-1 ）. The climate characteristics of different provenances and soil features of each seedcollected place were analyzed to find out the correlations between seed germination characteristics and ecological factors. The results showed that seed germination rate, germination index and vitality among 5 different provenances were significantly different（P〈0.05）. Seeds from provenance D （Ganjiahu provenance） had the highest germination rate （19.19%）, germination index （4.14） and vitality （15.57 %）,which were 12%-15%,2-2.7,and 8%-11%,respectively for the seeds of other 4 provenances（P〈0.05）. Under 25 mmol·L^-1 NaCl treatment,except for the seeds of provenance E, the germination rates of other 4 provenances increased in different levels （11%- 35%） comparing with the control, and the relative salt harm rate also exhibited negative values（P〈0.05）. Seed germination rate from all provenances decreased signifi cantly under 50 mmol·L^-1 NaC1 treatment（P〈0.05）. Leaves from provenance E had the lowest values of specific leaf area,and provenance D had the highest values comparing with other provinces（P〈0. 05）. There was positive significant correlations between seed germination rate and average precipitation, as well as pH values in soil 40 cm depth（P〈0.05）. These results indicated that low salinity （25 mmol·L^-1） favored the seed germination of P. euphratica, but higher level of salinity inhibited the seed germination. NaCl concentration between 145--192 mmol·L^-1 was the critical concentration for the seed germination. The results would provide scientific basis for selecting highly salt resistant seeds of P. euphratica.
出处
《西北林学院学报》
CSCD
北大核心
2017年第4期13-21,68,共10页
Journal of Northwest Forestry University
基金
新疆维吾尔自治区科技支撑计划项目(201431125)
关键词
胡杨
生境
盐胁迫
种子萌发
耐盐阈值
Populus euphratica
habitat
salt stress
seed germination
threshold salinity
