台灣土壤中立枯絲核菌不同菌群之研究

Anastomosis Groups of Rhizoctonia Solani in Taiwan Soils

莊再揚(T. Y. Chuang)

《植物病理學會刊》 6卷4期 (1997/12) Pp. 163-170

https://doi.org/10.6649/PPB.199712_6(4).0003

摘要

比較大豆莖桿、花生莖桿及稻桿誘釣土壤中立枯絲核菌不同菌群之14個標準菌株的效果，以大豆莖桿的誘釣效果最好，花生莖桿次之，稻桿較差。由全省各地採集429個土壤樣品，以大豆莖桿誘釣，其中183個土壤樣品可分離到絲核菌，而不能分離到絲核菌之土樣以溼篩法篩出有機質，置放於KHAD選擇性培養基上，仍然無法分離到絲核菌。在此183個土樣分離到的1,366個菌株中，115個土樣之801株為立枯絲核菌；93個土樣之441株為雙核似絲核菌，29個土樣之124株屬Waitea spp。在同一個土樣中可以分離到不同種的絲核菌或立枯絲核菌的不同菌群。所分離的立枯絲核菌可鑑定出AG-1、AG-4及AG-7等三個已知菌群；AG-4及AG-7分別由65個及41個土樣獲得，普遍分布於全省各地土壤；AG-1由4個土樣獲得，分別來自雲林、屏東和台東。另外7個土樣所得的41個菌株無法與所有供試標準菌群作菌絲融合。以蘿蔔幼苗作病原性測定，結果顯示AG-4的62個菌株中，有4株為弱病原性外，其餘均具強病原性；而AG-7的41個菌株供試，衹有3株具弱病原性，其餘均無病原性；AG-1的4個菌株供試，有2株為強病原性。另外無法歸類的立枯絲核菌7株供試，其中3株具強病原性，4株為弱病原性。以15種作物幼苗作接種試驗，結果顯示AG-4的病原性最強，但即使同一菌群的不同菌株，病原性差異亦很大。未歸群的立枯絲核菌，依據菌絲融合可分為四群。它們的菌絲生長均不需要Thiamine。將41個菌株作有性世代的誘導，結果只有1株成功，而經鑑定結果為Thanatephorus cucurneris。

關鍵字

立枯絲核菌 ； 菌絲融合群 ； 雙核似絲核菌

並列摘要

Compared the baits efficiency to isolate different anastomosis groups (AGs) of Rhizocto- nia solani from artificially infested soil, soybean stem was the most effective, followed by peanut stem, rice staw was the least. One thousand three hundred and sixty-six isolates of Rhizoctonia spp. were isolated from 183 out of 429 soil samples collected throughout the Island by using soybean stems as baits. Among them, 801 isolates from 115 soil samples were identified as R. solani, 441 isolates from 93 soil samples were binucleate Rhizoctonia, and 124 isolates from 29 soil samples were Waitea spp. Three AGs, i.e. AG-1, AG-4, and AG-7 were identified from these R. soIani isolates. AG-4 and AG-7 were widespread in Taiwan soils. Forty-one isolates of R. solani from 7 soil samples were not capable of fusing with all testers which included AG-1 ~ AG-10 and AG-BI. Pathogenicity test showed that AG-4 was the most virulent to the seedlings of 15 crops tested, as compared to AG-1 and AG-7. In addition, viru-lence of different isolates tested might vary within the same anastomosis group. All 41 isolates belonged to unidentified anastomosis groups of Rhizoctonia solani were thiamine-autotrophic. On the basis of reciprocal pairings, these isolates might be divided into four anastomosis groups. Only one out of 41 isolates was capable of producing perfect stage by soil-covered method and identified as Thanatephorus cucumeris.

並列關鍵字

Rhizoctonia solani ； anastomosis group ； binucleate Rhizoctonia