病理简答油料（The pathological use of oil）.docVIP

病理简答油料（The pathological use of oil） 1. What are the main symptoms of Sclerotinia sclerotiorum in rape? Answer points: At seedling stage, reddish brown spots appear on the root, neck and petiole near the ground and turn white. The diseased tissue becomes soft and rotten and has white hyphae, which can cause the death of the miao. Adult leaves, stems, flowers, fruits and seeds are susceptible to disease. A dark dark bluish water blotch after leaf sense, followed by a large rounded or irregularly shaped spot. Grey brown or brown spots, with concentric rings, the periphery of the outer edge of dark blue, yellow halo. When wet spots spread quickly, whole leaf dry rot; when the lesion of perforation. The stem lesion was hygrophanous, light brown, prismatic, oval, elongated shape around the stem leaf. The lesion slightly concave, with concentric rings, the middle edge of white, brown, disease, health department at the junction of obvious. When the disease is serious, the disease stems are full of flocculent hyphae, so they are called white stalk and mildew stalk. At this point, the plants died or died prematurely, and the longitudinal fissure of the cortex was seen. Pod susceptible form irregular white spots. After seed disease, the surface is rough, gray and dull. The size of the stool shape can be formed at the onset of Sclerotinia stem and pod on the outside. 2. What are the characteristics of soybean dodder? Answer points: Dodder leaves reduced to scales without chlorophyll, stems filiform, yellow or reddish. Flowers small, white or pale red, clustered, capsule dehiscent, seeds 2~4, seeds elliptic, pale yellow brown, endosperm fleshy, embryo curved, linear. The seed reproduction ability of Cuscuta chinensis is very strong. A dodder can continuously kill 300 soybean plants, and the broken dodder stem and bine can develop into a new plant and continue to damage as long as there is a growing point. Seed germination of Cuscuta requires more than 15 degrees of temperature a