膏桐实生苗与扦插苗的抗旱性对比研究

Comparative Study on Drought Resistance of Seedling and Cutting of Jatropha curcas

摘要: 近年来，云南遭受了百年不遇的严重旱灾，林业工程造林正面临着艰巨的考验，培育优良的抗旱树种及探索其抗旱机制显得尤为重要。因此，通过水分梯度法控水，我们从生长指标和生理生化指标等方面研究两种不同繁殖方式的膏桐(扦插苗与实生苗)的抗旱性，并利用SPSS软件进行方差分析和相关性分析、应用隶属函数法对其抗旱能力作出综合评价及比较。结果表明：1) 在不同程度干旱胁迫下，两种不同繁殖方式的膏桐苗木成活率均达到了100%，在重度干旱胁迫的中后期和末期部分叶片才出现了萎蔫、叶片卷曲、枯萎、落叶等现象；2) 膏桐实生苗和扦插苗的苗高生长均受到抑制，且随着干旱胁迫程度的加剧、时间的延长，苗高生长量受抑程度增加；3) 植株总干重、茎干重、叶干重和根干重均呈现下降趋势，与对照相比，膏桐实生苗上述指标的降幅均低于膏桐扦插苗；4) 与对照相比，膏桐实生苗及扦插苗苗木的根冠比都随着干旱胁迫强度的加强和胁迫时间的延长而呈现出明显的上升趋势；5) 苗木叶片相对含水量下降，下降幅度与干旱胁迫强度及时间成正比，且繁殖方式不同，下降幅度不同。由此可知：无论哪种繁殖方式的膏桐在干旱胁迫条件下苗木仍能维持较正常的生理过程，保持相对高的生长速率，抗旱能力较强。根据各项生长指标来判断，膏桐实生苗的抗旱生长略高于膏桐扦插苗。

Abstract: In recent years, Yunnan had suffered from the worst drought in a century, and there was the big-gest challenge in front of the development of forestry industry, whereupon it would be particularly important for us to cultivate improved drought-resistant species and research its drought resistance mechanism. Therefore the drought resistance of two different modes of reproduction (seedlings and cuttings) of Jatropha curcas was researched from the growth indexes, physiological and biochemical indexes with the moisture gradient method to control water. And then the comprehensive evaluation and comparison of their drought resistance ability was made by use of variance analysis, correlation analysis and application method of subordinate function in SPSS software. The results showed that : 1) under the different degree of drought stress, the survival rate of those two different modes of reproduction seedlings were both up to 100%, and most of leaves didn’t appear wilting, leaf curl, fallen leaves at the middle, late and last phase until under the severe drought stress; 2) the growth in seedling height was restrained with the increase of drought stress degree and the extension of time; 3) the total dry weight of the plant, stem, leaves and root were all in downtrend, compared to check samples, the decline range of above indexes of cuttings of Jatropha curcas was lower than its seedlings; 4) compared to check samples, the root shoot ratio of those two different seedlings took on apparent uptrend along with the increase of drought stress degree and extension of time; 5) the relative water content of seedling leaves declined, and the decline range was in proportion to the degree of drought stress and the length of time. And those two modes of reproduction differed in the decline range. It can be seen that Jatropha curcas seedling in whatever kind of reproduction still could maintain its normal physiological process, maintain relatively high growth rate and drought resistance ability. According to the drought coefficient and the relative growth in seedling height, the drought-resistant growth of cuttings was a little higher than that of seedlings.