Wu Bingyun, Nara Kazuhide, Hogetsu Taizo
Research Unit for Symbiotic Function, Asian Natural Environmental Science Center, The University of Tokyo, Midori-cho 1-1-8, Tanashi, Tokyo 188-0002, Japan.
New Phytol. 2001 Jan;149(1):137-146. doi: 10.1046/j.1469-8137.2001.00010.x.
• Movement of C-labeled photosynthetic products via ectomycorrhizal mycelia linking seedlings of Pinus densiflora is investigated here, a process which may have the potential to be highly ecologically significant. • Paired seedlings linked by hyphae of either an unidentified ectomycorrhizal fungus designated T01 or Pisolithus tinctorius were prepared by arranging mycorrhizal and nonmycorrhizal seedlings in an observation rhizobox and allowing mycelial links to form. Shoots of the initially mycorrhizal seedling were photosynthetically labeled with CO and movement of C chased by time-course autoradiography. • Within 3 d, C was transferred to mycelia and mycorrhizas formed on the unlabeled seedling, but little C was subsequently transferred to the roots and shoots. The reverse movement of label was also demonstrated. Mycelial fans of T01, with greater hyphal density, accumulated more C than mycelia of P. tinctorius, whereas higher radioactivity was detected in hyphal strands than in the mycelial front of P. tinctorius. • Ectomycorrhizas and mycelia are strong sinks for photosynthetic products, and C transfer can occur bi-directionally in the mycelia. However, as yet no direct evidence indicates any benefit to receiver plants and, thus, supplementary supply of C to understory individuals may not be ecologically significant.
• 本文研究了通过连接赤松幼苗的外生菌根菌丝体运输碳标记光合产物的过程，这一过程可能具有高度的生态意义。• 通过在观察根箱中排列菌根和非菌根幼苗并让菌丝连接形成，制备了由未鉴定的外生菌根真菌T01或彩色豆马勃的菌丝连接的配对幼苗。最初菌根化的幼苗的地上部分用¹⁴CO₂进行光合标记，并通过时间进程放射自显影追踪¹⁴C的移动。• 在3天内，¹⁴C转移到菌丝体和在未标记幼苗上形成的菌根，但随后很少有¹⁴C转移到根和地上部分。也证明了标记的反向移动。T01的菌丝扇，菌丝密度更大，比彩色豆马勃的菌丝体积累了更多的¹⁴C，而在彩色豆马勃的菌丝束中检测到的放射性比其菌丝前端更高。• 外生菌根和菌丝体是光合产物的强大汇，¹⁴C转移可以在菌丝体中双向发生。然而，目前尚无直接证据表明对接收植物有任何益处，因此，向林下个体补充碳供应可能在生态上并不重要。
