干旱胁迫下内生真菌感染对黑麦草光合色素和光合产物的影响  

Photosynthetic pigments and photosynthetic products of endophyte-infection and endophyte-free Lolium perenne L. under drought stress conditions

作　　者：任安芝[1] 高玉葆[1] 王巍[1] 王金龙[1] 

机构地区：[1]南开大学生命科学学院,天津300071

出　　处：《生态学报》2005年第2期225-231,共7页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目 (G2 0 0 0 0 1860 1) ;国家自然科学基金资助项目 (3 0 3 70 2 3 9);教育部科学技术研究重点资助项目(0 3 0 46)~~

摘　　要：以含有内生真菌的黑麦草 (L olium perenne L.)种子为材料 ,采用加热处理方式构建内生真菌非感染的黑麦草种群 ,通过比较内生真菌感染 (EI)和非感染 (EF)植株在正常条件下和干旱胁迫条件下叶片相对水分含量、叶绿素、可溶性糖和淀粉含量等指标的差异 ,探讨黑麦草 EI和 EF种群对干旱胁迫的适应性差异。结果表明 :在中度胁迫后期 ,EI植株叶片的 RWC显著高于 EF植株 ,即 EI植株的保水能力更强。轻度水分胁迫下 ,内生真菌感染可使其宿主植物的可溶性糖含量增加 ,以增强宿主的渗透调节能力 ,随着干旱胁迫强度的加大 ,内生真菌的这一增益效应不再起作用 ,此时 ,宿主植物将更多的光合产物——淀粉积累于体内 ,以度过不良环境。第 2年春天 EI和 EF种群的恢复生长情况进一步表明 ,经过中度干旱胁迫后 ,EI种群的恢复更为迅速。生物量的大小是植物种群净光合作用能力的直接体现 ,研究中在中度干旱胁迫条件下 ,黑麦草 EI种群的生物量显著高于EF种群 ,但从光合色素的变化来看 ,相同水分状况下 EI和 EF植株的 Chla、Chlb以及 Car的变化趋势比较接近 ,这说明内生真菌感染并未缓解干旱胁迫对光合色素的破坏 。Endophytes and their host grasses are mutually symbiotic. On one hand, the grasses provide photosynthates for the fungi; on the other hand, the endophytes may enhance the host’s growth and protect the host from biotic stresses (such as mammalian, insect, and nematode herbivores) and abiotic stresses (such as drought and high temperature). In the past, much research work has been done on the beneficial effect of endophyte infection on biotic stress resistance of grasses. When abiotic stress, such as drought, was regarded, most research work focused on several agronomy indexes. Thus, in this paper Lolium perenne cv SR4000 infected by Neotyphodium lolii was chosen as experimental material. Relative water content (RWC), chlorophyll, soluble sugar and starch content of endophyte-infected (EI) and endophyte-free (EF) populations under normal and drought stress conditions were compared. EI seeds of Lolium perenne L. were used to attain EF population by heating the seeds at 43℃ for 15 min and then 57℃ for 25min. The experimental seedling was bred in winter during 1998, and then populations were constructed twice with ramets in April 1999 and April 2000 separately. EI and EF populations were transplanted into the soil column system designed for the experiment. Each system was comprised of a cylinder-shaped tinplate sleeve filled with soil and fixed in the ground. The system was 25cm in diameter and 60cm in depth. The top 0～25cm layer was filled with a compound of soil, sand and biological fertilizer (soil∶sand∶biological fertilizer=18∶10∶1). Each column contained approximately 14.3kg oven-dried soil. Field capacity and permanent wilting point were 18.53% and 8.31% respectively. Eighteen column systems were made as required. The experimental populations were treated by cyclic drought stress where three stress levels were designed, i.e. control, mild and moderate level. The stress treatment period was from Sep. 29, 2000 to Nov. 7, 2000, and sustained for 40 days. In this period, the control set was w

关 键 词：内生真菌 黑麦草 RWC 可溶性糖 淀粉 

分 类 号：S182[农业科学—农业基础科学]