洋香瓜囊叢枝內生菌根菌與根瘤線蟲之相互關係

Interaction of Vesicular-arbuscular Mycorrhizal Fungus with Root-knot Nematode in Muskmelon

程永雄(Cheng, Y. H.) ； 莊明富(M.F Chuang) ； 蔡東纂(T.T Tsay)

《植物病理學會刊》 10卷1期 (2001/03) Pp. 19-26

https://doi.org/10.6649/PPB.200103_10(1).0003

摘要

為探討囊叢枝內生菌根菌(VAM fungus) Glomus clarum 與根瘤線蟲Meloidogyne incognita在洋香瓜根系內之相互關係及對其生長之影響，進行二者之單獨及混合接種，以菌根之形成率、根瘤線蟲為害洋香瓜根部所形成之根瘤數及其繁殖數、及對洋香瓜生長之影響，來明瞭兩者在宿主植物內之相互影響關係。測定根瘤線蟲最初感染源濃度(Initial inoculum density)，顯示每盆（株）接種5隻二齡線蟲即可感染成功，在根部產生根瘤；接種50隻者8星期後即可造成根部之傷害，每株罹患根瘤數平均為221個；每株植物接種100隻線蟲，即可產生580根瘤。於二者相互關係接種試驗，即採用每株接種50隻二齡線蟲。因囊叢枝內生菌根菌完成感染根部之時間比線蟲侵染所需之時間為長，故內生菌根菌之處理採先行接種2星期，再進行線蟲混合接種或單獨接種。處理計有：（一）單獨接種囊叢枝內生菌根菌(M)，（二）囊叢枝內生菌根菌再接種根瘤線蟲(M+N)，（三）單獨接種根瘤線蟲(N)，（四）對照不接種菌根菌及根瘤線蟲(Ck)。於根瘤線蟲接種後8星期調查，試驗結果顯：示囊叢枝內生菌根菌處理者(M)可促進植株地上部及地下部之生長，其每株平均鮮重分別為63.3公克及8.14公克，菌根形成率73.3%；對照植株(Ck)分別為47.6公克及6.98公克；而根瘤線蟲處理者(N)則植株與根系生長均受抑制，每株平均鮮重分別為41.9公克及6.82公克，根部罹根瘤數103個。若有菌根菌存在時，可減輕根瘤線蟲之為害，囊叢枝內生菌根菌與根瘤線蟲之混合接種處理者(M+N)，植株地上部與地下部之每株平均鮮重分別為49.5公克及7.40公克，根部罹根瘤數65個，菌根形成率78%。根瘤線蟲之存在不影響囊叢枝內生菌根菌感染洋香瓜根部形成菌根，然而囊叢枝內生菌根菌之存在，可能因侵染點之佔據，減低線蟲之侵染，使得洋香瓜根系之根瘤數目減少，進而影響根瘤線蟲之繁殖。應用囊叢枝內生菌根菌防治作物根瘤線蟲，應預先培育囊叢枝內生菌根曲，再移植於本田，即使有根瘤線蟲存在，也可減輕其為害。

關鍵字

洋香瓜 ； 根瘤線蟲 ； Meloidogyne incognita ； 囊叢枝內生菌根菌 ； Glomus clarum

並列摘要

Glomus clarum and Meloidogyne incognita were separated or mixed to inoculate the root systems of muskmelon for study of the effect of interaction between VAM fungus and nematodes on the host development. The interaction effects were determined and evaluated by the degree of formation of VA mycorrhiza and root knots in root systems, and the growth of the host plant. To find the minimal inoculum density of nematodes for inducing disease symptoms, seedling root systems were inoculated with 0, 5, 10, 25, 50, 100 or 200 larvae of the 2nd stage nematodes in each pot. Results showed that 5 larvae per seedling inoculation could induce formation of root knots in the host. Whereas 50 and 100 larvae per seedling, causing serious damage to root systems, induced 221 and 580 root knots, respectively, in average after inoculation for 8 weeks. VA mycorrhiza was formed in the seedling root of muskmelon after inoculation with chlamydospores of G. clarum for 2 weeks. When host growth and disease incidence of the seedlings pre-inoculated with G. clarum for 2 weeks and then inoculated with 50 larvae of M. incognita per plant were studied, and compared with those inoculated with G. clarum or M. incognita individually. Results showed that G. clarum individual stimulated both top and root growth of muskmelon whereas M. incognita inhibited the top growth. After 8 weeks inoculation, the average fresh weight of ground parts of muskmelon seedlings treated with G. clarum plus nematode (M+N), G. clarum (M), nematode(N), and controls(CK) were measured as 49.5, 63.3, 41.9, and 47.6g, respectively. Whereas the root systems of the four treatments were as 7.40, 8.14, 6.82, and 6.98g, respectively. This indicated that inoculation of G. clarum in muskmelon root could decrease the host damage caused by M. incognita. Results also showed that nematodes were unable to attack the mycorrhizal occupation parts of root systems. The number of root knot produced in the treatments of inoculated with G.. clarum plus nematode (M+N) and individual nematode (N) were 65 and 103 per plant, respectively. Meanwhile, the percentage of formation of mycorrhizal root in the treatments of G. clarum plus nematode (M+N) and G. clarum (M) were 78% and 73.3%, respectively. This indicated that nematode was also unable to interfere the formation of mycorrhizal roots in this study.

並列關鍵字

muskmelon ； root-knot nematode ； vesicular-arbuscular mycorrhizal fungus ； Glomus clarum ； Meloidogyne incognita