小叶蚊母及其不同品系的耐盐性研究

采用盐水浇灌试验,设置0mmol·L-1(对照)、80mmol·L-1(轻度盐化)、100mmol·L-1(中度盐化)、200mmol·L-1(重度盐化)NaCl和300mmol·L-1(盐土)溶液共5个盐分梯度,通过分析小叶蚊母叶片受害面积比例、相对含水量、相对电导率、叶绿素含量、MDA含量、SOD活性、CAT活性等指标研究其耐盐性,并进一步探讨了小叶蚊母原种(D)及其不同品系(D1、D4、D6、D7、D10、D13)对中度盐胁迫(100mmol·L-1 NaCl)的生理响应,对其耐盐性进行综合评价。结果显示:(1)随着胁迫时间增加,各浓度处理下小叶蚊母的形态指标、生理指标发生显著变化,15d后仅100mmol·L-1盐胁迫浓度以下植株存活。(2)在中度盐胁迫下,小叶蚊母品系D1和D13的叶片受害面积比例显著小于其它品系,同时原种以及各品系间的各项生理指标差异显著,各项生理指标测定结果均表明D1和D13的耐盐性相对较好。(3)采用隶属函数法对原种及不同品系的耐盐性综合评价结果显示,各材料耐盐性由高到低依次为D1D13DD7D10D4D6。研究表明,小叶蚊母不适宜种植在土壤盐度100mmol·L-1以上的区域,在中度以下盐渍化地区绿化应用中建议优先选用品系D1和D13。

Tolerance and Physiological Response of Distylium buxifolium and Its Cultivars to Salt Stress

We irrigated Distylium buxifolium with different concentrations of NaCl solution(0,80,100,200,300 mmol·L^-1),to evaluate salt-tolerance by indexes such as rate of injured area,relative water content,relative conductivity,chlorophyll content,malonicaldehyde(MDA) content,superoxide dismutase(SOD) activity,catalase(CAT) activity.Furthermore,the responses to moderate salt stress(100 mmol·L^-1 NaCl) of D.buxifolium(D) and its cultivars(D1,D4,D6,D7,D10,D13) were also compared.The results showed that:(1)The morphological and physiological indexes of D.buxifolium changed significantly under different salt concentrations.After 15 days,only those irrigated with NaCl solution below 100 mmol·L^-1 were still alive.(2)Under moderate salt stress(100 mmol·L^-1 NaCl),the rate of injured area of D1 and D13 is significantly smaller than that of other cultivars and the difference in all these indexes of D.buxifolium and its cultivars is significant.Meanwhile,the physiological response of D1 and D13 showed that the salt tolerance of these two cultivars might be higher than that of others.(3)The method of fuzzy cluster was used to evaluate the salt tolerance among different cultivars,which showed that the salt-tolerance order was D1>D13>D>D7>D10>D4>D6.Therefore,it is not appropriate to plant D.buxifolium in the area where salt concentration is above 100 mmol·L^-1.In light and moderate salinized areas,D1 and D13 would be the priority selections.