枣锈病初侵染来源的研究

试验测定了外来菌源与发病关系、冬孢子及转主寄主、越冬夏孢子的侵染和发病。自７月１日～９月２２日捕捉空中夏孢子、夏孢子的始见期为病害零星发生期。此后，随病情增长，空中夏孢子数上升，表明枣锈病无外来菌源。在越冬后的病叶上刮取的大量夏孢子中，混有少量冬孢子。夏孢子、冬孢子比约为２１４．５５：０．７７，冬孢子平均萌发率为２７．４８％，用与枣林混生的杂草及小灌木上的锈孢子接种于枣叶上，未见发病。因此，至今未发现转主寄生，冬孢子作用不明。在病叶上越冬的夏孢子萌发率０．９８％～７．１１％，平均萌发率为３．１５％。用越冬夏孢子接种大枣可以导致发病。因此初步明确枣锈病无外来首源及转主寄主，冬孢子数量极少，作用不明，其主要的初步侵染源为当地病叶上越冬的夏孢子堆。

Study on Prelinary Infection Source of Phapsoro zizphi-vugaris(P.Hemn) Diet

Phapsoro zizipli-vugaris was one of the three main and epidemic diseases in Jujube trees,especially as an important epidemic disease in″Da Zao″and″Jin St Xiao Zao″.Yellowish-brown summer spore stack was produced greatly along main and branch veins on the back side of leaves after infection, which induced leaves fallen earlier resulting in low yield and quality. Systemic Investigation was carried out on elementary infection source and the role of winter and summar spores in infection cycle during 1991～1993.