关于梨黑星病菌的越冬方式和有性世代的形成,在国内报导颇不一致。今就莱阳梨区的情况,作一简报。根据我们1961—1962年两年的观察,有性世代的形成不一定经过一个寒冷的冬天,只要具有一定的湿度(相对湿度60%),越冬前皆能形成。1962年2月31日调查有46.6%的罹病叶片中已形成了子囊壳,翌春落叶上的菌丝体也有1/6的能形成子囊世代。这说明子囊壳的形成与温度的关系不如湿度密切。人工诱发产生子囊壳,只要保持湿润状态在10—25℃均可形成。同时,砂壤土有利于子囊世代形成,砂土次之,粘土最差(形成百分率依次为:72.7%,52.7%,29.8%),可能因为砂壤土具有良好的土壤结构,不仅保水性能好,而且有较好的通气条件。根据人工诱发产生子囊壳和田间观察发现,凡落叶被细砂掩埋(1—2厘米)或渠道两旁的落叶,90%以上能产生有性世代,斜置于土壤中的叶片则多形成于地下部 About the pear overwintering way and the formation of a sexual generation, reported in the country is quite inconsistent. Now Laiyang pear District situation, make a briefing. According to our two years of observation from 1961 to 1962, the formation of the sexual generation does not necessarily go through a cold winter, as long as it has a certain humidity (relative humidity of 60%), can be formed before the winter. On February 31, 1962, 46.6% of diseased leaves had formed ascus shells, and one sixth of the mycelium on fallen leaves of next spring formed ascus. This shows that the formation of ascus shell temperature and humidity less closely. Induced generation of ascochondral shell, as long as the state is maintained at 10-25 ℃ can be formed wet. At the same time, sandy loam is beneficial to the formation of the ascus, followed by the sand, the worst clay (the formation percentage of 72.7%, 52.7%, 29.8%), probably because sandy loam has good soil structure, Have better ventilation. According to the artificial induced generation of ascus shell and field observation found that where the leaves are buried by fine sand (1-2 cm) or the leaves on both sides of the leaves, more than 90% can produce sexual generation, obliquely placed in the soil leaves are formed in the ground unit