不同灌水处理对小桐子生长及耐盐性的影响

为研究不同灌水处理对小桐子生长及耐盐性的影响,取1 a生小桐子幼苗为试验材料,设置19.80,19.80和39.60(交替灌溉),39.60 mm 3个水平的灌水处理;3个水平的施盐处理:每50 g风干土中NaCl分析纯为0,0.15,0.30 g,并监测小桐子的形态,根区Na⁺环境以及植物体Na⁺累积的情况.结果表明:小桐子有一定的耐盐性,受到每50 g风干土中含有0.30 g NaCl分析纯盐胁迫时,交替灌溉处理更有利于小桐子的生长;随着盐浓度的增大,小桐子根区土壤电导率增大的幅度逐渐减小,同时,盐浓度的增大使土层中Na⁺含量增大的幅度也逐渐减小,小桐子干样中各器官Na⁺含量从大到小依次为叶片、根部、茎;19.80 和39.60 mm交替的灌溉方式比39.60 mm灌溉方式节水25%,但小桐子的生长并未受到影响,且各器官钠离子含量差异不具有统计学意义.本试验条件下,受到不同程度盐胁迫的小桐子,19.80和39.60 mm交替的灌溉方式更有利于小桐子生长,提高其耐盐性.

Effects of irrigation on growth and salt tolerance of Jatropha curcas

Appropriate irrigation is beneficial to the growth of Jatropha curcas. In order to study effects of irrigation on growth and salt tolerance of Jatropha curcas, seedlings of Jatropha curcas for 1a were used as experimental materials. The irrigation had three levels, i.e. 19.80 mm, 19.80 mm and 39.60 mm alternating irrigation, and 39.60 mm. NaCl was subject to three levels of analytical purity in 50 g air-dried soil such as 0 g, 0.15 g and 0.30 g. The morphology of Jatropha curcas, Na⁺ environment in its root zone and Na⁺ accumulation in its plant body were monitored. The results show that the Jatropha curcas has a certain salt tolerance, and the alternating irrigation is more conducive to the growth of Jatropha curcas at 0.30 g NaCl level. With increasing salt concentration, the increment of soil electrical conductivity in the root area of Jatropha curcas decreases gradually. At the same time, the increment of salt concentration also reduces with the increase of Na⁺ content in soil layer. The Na⁺ content in the organs of Jatropha curcas from the highest to the lowest is leaf, root and stem. The alternating irrigation of 19.80 mm and 39.60 mm can save 25% water in comparison with that in 39.60mm irrigation, but the growth of Jatropha curcas remains unaffected. Further, there is no significant difference in Na⁺ content in various organs. Under the conditions of this experiment, when Jatropha curcas is under different degrees of salt stress, the alternate irrigation of 19.80 mm and 39.60 mm is more conducive to growth, and can improve ability of salt tolerance.