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4种典型滨海植物的耐盐能力

Salt tolerance of four typical coastal plants

  • 摘要: 滨海植物是海岸生态系统的重要组成部分,而绝大部分滨海植物的耐盐能力与生态适应机制尚不清楚,本研究选择马鞍藤(Ipomoea pescaprae)、小刀豆(Canavalia cathartica)、全缘冬青(Ilex integra)、大叶银边海桐(Pittosporum pentandrum)4种滨海典型植物,通过对培养基质及植株叶片施加不同浓度的盐溶液,研究其根系和叶片的耐盐能力。主要结果如下:①根系胁迫中,盐度10导致大叶银边海桐、全缘冬青、小刀豆的老叶变黄或产生黄褐斑,盐度20和30促使植物叶片干枯、落叶,对叶片的损害从叶柄向叶脉延伸;盐度为30的叶片盐胁迫导致少量叶片从叶尖开始干枯;②小刀豆、马鞍藤、全缘冬青与大叶银边海桐分别可耐受盐度为10、20、20、30的短期(49 d)根系盐胁迫,藤本植物的耐盐能力为马鞍藤>小刀豆,灌木的耐盐能力为大叶银边海桐>全缘冬青;4种植物均可耐受盐度30的叶片盐胁迫,耐盐能力为马鞍藤>全缘冬青>大叶银边海桐>小刀豆。结果表明,植物的生长状态值对植物耐盐能力的指示作用更为准确与直观;4种植物均有较强的耐盐能力,均可以作为海岸带、海岛的植被修复品种。植被修复实践中应综合考虑修复位置的海岸高程和离海距离,海水与海浪的影响状况,确定适宜的的植物品种。

     

    Abstract: Coastal plants are important members of coastal ecosystem, however the knowledges of salt tolerance and their ecological adaptations have not been fully understood yet. In this paper, salt tolerance of four typical plants, Ipomoea pescaprae,Canavalia cathartica,Ilex integr and Pittosporum pentandrum, are studied for purpose of coastal vegetation restoration. The plants were exposed to different gradient of NaCl solutions used leaf surface spray and root system absorption and the plant status, equivalent water thickness and chlorophyll content were observed and measured. The main results included that the salinity of 10 turned the old leaves of P. pentandrum,I. integra and C. catharticayellow or caused yellow-brown spots. The salinities of 20-30 caused plant leaves to wither extending from the petiole to the vein and fall. The salinity of 30 caused some leaves to wither from the tip of leaves. Moreover,I. pescaprae,C. cathartica,I. integr and P. pentandrum could tolerate salinities of 10, 20, 20 and 30 in short-term stress on the roots, respectively. For Liana, the salt tolerance of I. pescaprae was higher than that of C. cathartica. While for dungarunga, the salt tolerance of P. pentandrum was higher than that of I. integra. All leaves of 4 plants su- stained the salinity stress of 30, the salt-tolerant ability turns out to be I. pescaprae>I. integra>P. pentandrum>C. cathartica. The results showed that the indexes of plant status gave better indications of salt tolerance. All 4 plants of high tolerance under salt stress can be used for coastal vegetation restoration. In practice, factors of coast elevations, distance to the sea, water and wave effects should all be fully considered in choosing proper plants for the restoration.

     

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