Smolinska Urszula, Knudsen G R, Morra M J, Borek V
Visiting Scientist.
Associate Professor.
Plant Dis. 1997 Mar;81(3):288-292. doi: 10.1094/PDIS.1997.81.3.288.
Seed meal from Brassica napus (rapeseed) produced volatile fungitoxic compounds potentially of value in the control of Aphanomyces root rot of pea. Hyphal growth, germination of encysted zoospores, and oospore survival and inoculum potential, were determined in the presence of volatiles produced from B. napus seed meal. Volatile compounds from B. napus meal completely suppressed mycelial growth and germination of encysted zoospores on agar. In growth chamber bioassays, pea (Pisum sativum) seed inoculated with zoospore suspensions and incubated 24 h in the presence of volatiles from rapeseed meal had 50% lower root rot disease severity than in the absence of meal. Volatile compounds passing through soil also significantly decreased survival and inoculum potential of oospores. Gas chromatographic analysis of rapeseed tissues and the volatile compounds evolved from tissues showed that substrate glucosinolates were hydrolyzed enzymatically to produce mainly isothiocyanates. Non-autoclaved rapeseed meal produced significantly higher levels of volatile compounds than did autoclaved meal. Also, volatile compounds produced from autoclaved meal were dominated by nitriles, whereas isothiocyanates were more common volatile products from non-autoclaved meal. Our results indicate that B. napus allelochemicals responsible for toxic effects toward A. euteiches f. sp. pisi are enzymatic hydrolysis products of glucosinolates.
甘蓝型油菜（油菜籽）籽粕产生的挥发性真菌毒性化合物可能对控制豌豆的腐皮镰孢根腐病具有价值。在存在甘蓝型油菜籽粕产生的挥发物的情况下，测定了菌丝生长、包囊游动孢子的萌发以及卵孢子的存活和接种潜力。甘蓝型油菜籽粕中的挥发性化合物完全抑制了琼脂上的菌丝生长和包囊游动孢子的萌发。在生长室生物测定中，接种游动孢子悬浮液并在油菜籽粕挥发物存在下孵育24小时的豌豆（豌豆）种子，其根腐病严重程度比没有籽粕时低50%。穿过土壤的挥发性化合物也显著降低了卵孢子的存活率和接种潜力。对油菜籽组织及其产生的挥发性化合物进行气相色谱分析表明，底物硫代葡萄糖苷被酶水解主要产生异硫氰酸盐。未高压灭菌的油菜籽粕产生的挥发性化合物水平明显高于高压灭菌的籽粕。此外，高压灭菌的籽粕产生的挥发性化合物以腈类为主，而异硫氰酸盐是未高压灭菌的籽粕中更常见的挥发性产物。我们的结果表明，对豌豆专化型腐皮镰孢具有毒性作用的甘蓝型油菜化感物质是硫代葡萄糖苷的酶水解产物。
