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在河北省沙岭子农业試驗站和北京农業大学試驗农場1955和1956两年所进行的病薯栽培試驗,表示土中的重复侵染是中心病株形成过程的基本特征。当挖掘出土初期的病薯时,發現直接与种薯病斑相連的幼芽都在出土之前变黑死去,剛剛露土的幼芽中,靠近已死幼芽的莖基也开始部分变色,距离較远的则仍然健全。在已出土的衰弱幼苗上常常可以看到露在地面的莖基部分也显出暗褐色的病斑,但是沒有孢子囊,而該病斑的地下部分则披有一層孢子囊趺缜o斑并不全是达到莖基的終点,而达到莖基終点的,也不与种薯病斑相連接。1956年在两地播种的789穴病薯中發現了9株这种病苗,其中5株迅速萎蔫而枯死,1株發生莖斑痊愈現象。只有少数出現較晚而維持較长久的弱苗遇到适合气候时能够在地面上形成孢子囊傳染到本株或同穴中其他植株的叶片缙诓∶绲闹饕饔孟匀辉谟谛纬傻叵骆咦幽乙砸鹜ㄖ姓诔沙さ慕≈昵o基的感染。在成株莖部上病菌只能在皮层扩展引致条紋状的暗褐色病斑。这种病斑不严重影响植株的生长發育,但是在露出地面后随时可以形成孢子囊成为空中傳染的經常潜在来源。出土病苗的观察以及幼苗地上部接种試驗結果說明病害延迟流行的原因,一方面是受病的幼苗容易枯死,另一方面是在早期气候下不能得到形成孢子和再侵染所需要的温湿度的配合。建議在各地預测站选擇适当地点播种病薯,以便观察病害中心的發展情况,作为預測預报的根据。
The experiments on the cultivation of Chinese cabbage at Shalingzi Agricultural Experiment Station of Hebei Province and the Experimental Farm of Beijing Agricultural University in 1955 and 1956 indicated that the repeated infection in the soil was the basic characteristic of the formation process of the central diseased plants. When excavation of the early unearthed potato disease, found that the shoots directly connected with the seed potato lesions are black out before the excavated, just in the soil of young buds, the stems near the dead sprout also began to part of the color, distance The farther is still sound. It is often seen on the weakened seedlings that emerged from the ground that the stem-base portion of the ground also shows a dark brown lesion but no sporocysts, while the underground portion of the lesion is covered with a sporocyst, Not all to the end of the stem base, and reach the end of the stem base, nor with the potato disease spots connected. Nine strains of this disease were found in 789 potatoes planted in two places in 1956. Five of them were rapidly wilted and wilted, and one of them was cured. Only a few appear late and maintain the longer the weak seedlings Encounter the climate suitable for the formation of sporangium on the ground infected with other plants in this or the same hole in the leaves 诓 诓:叵 Luo 咦 secluded B 鹜 ㄖ surname 诔 sand 慕 Mo ≈ nicky o base infection. Germs on adult stems can only cause stripe-like dark brown lesions in the cortex. This lesion does not seriously affect the growth and development of plants, but sporangia can readily form a potential potential source of airborne infection when the ground is exposed. The observation of the excised disease seedlings and the seedling shoot inoculation test results indicate the reasons for the delay of the disease disease on the one hand that the diseased seedlings are easily dead and on the other hand the temperature and humidity required for sporulation and re-infestation can not be obtained in the early climate With the cooperation. It is suggested that sown potatoes should be planted at the appropriate stations in all the places so as to observe the development of the disease center and serve as a basis for forecasting and forecasting.