刈割对伊犁绢蒿根系贮藏营养物质的影响

以新疆蒿类半灌木荒漠草地建群种伊犁绢蒿为材料,探讨刈割强度对其根系贮藏营养物质的影响.结果表明:不同刈割强度间伊犁绢蒿根中可溶性蛋白、可溶性糖、还原糖含量差异显著(p<0.05),且轻度刈割与中度刈割下可溶性蛋白、可溶性糖、还原糖含量相对较高;不同强度刈割后伊犁绢蒿可溶性蛋白、可溶性糖、还原糖的含量随时间的变化先降低后升高,呈"V"型变化.由于刈割后伊犁绢蒿需要利用贮藏的淀粉维持其再生长,淀粉则呈现下降趋势.而研究结果显示,轻度刈割与中度刈割下淀粉含量相对较高,说明轻度及中度刈割强度下伊犁绢蒿根恢复效果较好,适度刈割有利于伊犁绢蒿可溶性蛋白、可溶性糖、还原糖及淀粉的积累,并可促进其再生长.

Imapcts of Mowing on Storage Nutrition Substance in Roots of Seriphidium transiliense

The sagebrush desert is a representative of spring and autumn pasture in north Xinjiang. However, the most severely overgrazing and grassland degeneration made the sagebrush desert become the bottleneck restricting development of seasonal stock raising in this area. To restore and manage the degraded pasture, some essential issues of plant composition and its storage nutrition nubstance of the pasture need to be resolved. Therefore, in the study, the low hills on the northern slope of the Bogda Mountains (840 ～1 110 m, 87°46′～87°47′ E, 43°49′～43°53′ N), where the most severely overgrazing and grassland degeneration occurred, is chosen as the target study area. Seriphidium transilien, a prominent plant in the community, was selected. The change of storage nutrition substance in Seriphidium transilien's roots, such as soluble proteins, soluble sugar, deoxidizing sugar and starch,were studied under various defoliation intensities. The results show that contents of soluble protein, soluble sugar and deoxidizing sugar of S. transillense roots are separately significant different under various defoliation intensities (p <0. 05 ) and the contents are higher under the moderate-defoliation and middle-defoliation. The temporal distribution of soluble protein contents, soluble sugar contents and deoxidizing sugar contents of S. transiliense roots emerged in a "V" pattern after the plant was defoliated. Because S. transiliense needs stored starch to maintain its regeneration after defoliating, the starch showed a descending trend, however the contents of starch was relatively higher in the light-defoliation and middle-defoliation. The recovery effect of nutrition substance was better under the moderate-defoliation and middle-defoliation suggesting that the moderate defoliation may be helpful to the accumulation of soluble proteins, soluble sugar, deoxidizing sugar and starch, and promoted regeneration of S. transiliense.