盐土和沙土对新疆常见一年生盐生植物生长和体内矿质组成的影响

Influence of saline soil and sandy soil on growth and mineral constituents of common annual halophytes in Xinjiang

选用古尔班通古特沙漠南缘荒漠-绿洲交错带常见的1年生盐生植物盐角草、刺毛碱蓬、叉毛蓬、猪毛菜和碱地肤为材料,比较了它们在原状盐土和沙土中的生长及体内矿质元素组成的差异。结果表明:①原状盐土0—100 cm各土层的pH值低于沙土,但电导率和含水量明显高于沙土;②原状盐土中生长的植物干重是沙土中生长植物干重的7—118倍,后者的根冠比是前者的2—6倍。③体现肉质化程度的地上部含水率为52%—81%,中低耐盐植物含水率在两种土壤中差异显著,强耐盐植物差异不显著;④5种1年生盐生植物地上部氮浓度为11—34 g/kg,在有效氮含量高的盐土上植物氮浓度也高;磷浓度为1—4g/kg,在有效磷高的盐土上植物磷浓度也较高(盐角草除外);但沙土中的植物地上部钾浓度明显高于盐土中植株的地上部钾浓度,这与两种土壤在0—60 cm土层中的钾浓度差异相反;⑤尽管原状盐土0—100 cm土层中的水溶性钙、镁、钠、氯、硫浓度显著高于沙土,盐土与沙土中生长的植物地上部钠、水溶性氯和硫的浓度比值远远低于土壤中的相应元素浓度的比值,甚至盐土中的植株钙、镁浓度等于或显著低于沙土中生长的植物。表明盐土不仅影响1年生盐生植物的生长,也显著影响这些植物对矿质元素的吸收和累积。1年生盐生植物能够选择性吸收不同生境中的矿质元素。为进一步深入研究盐生植物耐盐的适应机制提供依据,也可为植物修复盐碱土的品种选择提供参考。

In this study, five common annum halophytes （Salicornia europaea, Suaeda acuminate, Petrosimonia sibirica, Salsola subcrassa, Kochia scoparia） in hungriness-oasis ecotone of south border region of Gurbantonggut Desert were grown in undisturbed saline soil and sandy soil, and their growth and mineral constituents in shoots were compared. The results showed that ： 1 ） the pH value of the undisturbed saline soil was lower, while electrical conductivity and water content were significantly higher than those of the sandy soil in each of the soil layers from 0 to 100 cm in depth; 2） shoot dry weight （DW） of plants grown in the saline soil was 7 to 118 times higher than DW of plants grown in the sandy soil, and the root/ shoot DW ratio of plants in the sandy soil was 2 to 6 times higher; 3 ） water contents in shoots of these annum halophytesranged from 52% to 81%. The differences in shoot water content in the mid and low salt-resistant halophytes grown in both soils was significant （P〈0.05）, while that in the super salt-resistant halophytes grown in both soils were similar; 4） shoot N concentration of the 5 annual halophytes ranged from 11 to 34 g/kg and the higher the available N in soil, the higher the N concentration in shoots of these plants. Shoot P concentration ranged 1--4 g/kg. The correlations between the shoot P concentration and the available soil P were similar to that for N （except for S. europaeae ）. By contrast, shoot K concentration of the plants grown in sandy soil was higher than that of plants grown in saline soil, although K concentration in the 0--60 cm soil was higher in the saline soil than that in the sandy soil; 5 ） although the contents of the soluble Ca,Mg, Na, S and C1 in each layer of the soils from 0 to 100 cm in depth in saline soil were significantly higher than those in sandy soil, the ratios of the Na, C1 and S concentrations in shoots of plants grown in saline soil to those in sandy soil were far lower than those in the both soils, and even Ca and Mg concentrations in shoots of the plants grown in saline soil were equal or significantly lower than those in sandy soil. The results indicate that the saline soil significantly affects not only the growth of annual halophytes, but also the uptake and accumulation of the mineral nutrients by plants. The results could provide clues for the further studies on the adaptive mechanisms of halophytes to saline soil, and help select plant species for phytoremediation of saline soil.