Clay K
Department of Biology, Indiana University, 47405, Bloomington, IN, USA.
Oecologia. 1987 Sep;73(3):358-362. doi: 10.1007/BF00385251.
Many grasses are infected by endophytic fungi that grow intercellularly in leaves, stems, and flowers and are transmitted maternally by hyphal growth into ovules and seeds. The seed biology and seedling growth of endophyte-infected and uninfected perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) were investigated under controlled environmental conditions. The percentage of filled seeds produced by infected tall fescue was over twice of uninfected tall fescue; infected and uninfected perennial reegrass had similar percentages. Weights of seeds from infected and uninfected plants were similar in both species. Seeds from infected plants of both species exhibited a higher rate of germination than seeds from uninfected plants. Shoot growth in the greenhouse was compared by making three sequential harvests of above-ground plant parts from infected and uninfected plants of both species. Infected perennial ryegrass plants produced significantly more biomass and tillers than uninfected plants after 6 and 10 weeks of growth and significantly more biomass after 14 weeks of growth. Infected tall fescue plants produced significantly more biomass and tillers than uninfected plants after 10 and 14 weeks of growth. The physiological mechanism of enhancement of growth is not known. The results of this study suggest that infected plants may have a selective advantage in populations with uninfected members.
许多禾本科植物受到内生真菌的感染，这些真菌在叶片、茎和花的细胞间生长，并通过菌丝生长进入胚珠和种子进行母系传播。在可控环境条件下，对感染内生真菌和未感染内生真菌的多年生黑麦草（Lolium perenne）和高羊茅（Festuca arundinacea）的种子生物学和幼苗生长进行了研究。感染内生真菌的高羊茅产生的饱满种子百分比是未感染高羊茅的两倍多；感染内生真菌和未感染内生真菌的多年生黑麦草的百分比相似。两个物种中，感染和未感染植株的种子重量相似。两个物种中感染植株的种子发芽率均高于未感染植株的种子。通过对两个物种感染和未感染植株的地上部分进行连续三次收获，比较了温室中的地上部生长情况。生长6周和10周后，感染内生真菌的多年生黑麦草植株产生的生物量和分蘖显著多于未感染植株，生长14周后产生的生物量也显著更多。生长10周和14周后，感染内生真菌的高羊茅植株产生的生物量和分蘖显著多于未感染植株。生长增强的生理机制尚不清楚。本研究结果表明，在有未感染成员的种群中，感染植株可能具有选择优势。
