In order to explore the infection process of Heterodera glycines (SCN) in soybean field under the seasonally-changing characteristics of the meteorological coditions in 2014 , the soil and root samples were periodically collected from one fixed block in Zhucheng of Shandong Province .The nematodes were examined and counted under stereomicroscope after extracted from soil and stained in root .The results showed that there were three obvious occurrence peaks for both second -instar larvae ( J2 ) and fresh cyst in soil , and the maxi-mum density of 13.9 J2 and 26.3 fresh cyst per 100 g soil occurred on August 23 and August 17 respectively. J2 emerged in soybean root from May 17 to September 21 with two obvious peaks;the maximum density of 435 J2 per 5 g root occurred on August 4.The third and fourth larvae(J3+J4) emerged in root from May 24 to September 21 with two obvious peaks;the maximum density of 742 J3+J4 per 5 g root occurred on August 4. The results indicated that SCN occurred four generations in soybean in Zhucheng;the occurrence of the first generation was less and unobvious , and overlapped severely with the second generation;the occurrence amount of the third generation was the greatest ,and that of the fourth one took the second place .It was inferred that the continuous drought in the early growth period was the primary reason for the abnormal occurrence of the former two SCN generations .%为探究2014年气象季节变化特点下大豆孢囊线虫（ Heterodera glycines，SCN）的田间侵染进程，从山东省诸城市某大豆田块定点定期取样，对土壤中线虫进行分离及对根组织中线虫进行染色后镜检并计数。研究发现，土壤中2龄幼虫和新鲜孢囊均有3个明显发生高峰，最大密度分别发生在8月23日和8月17日，每100 g土壤分别有13．9条和26．3个。2龄幼虫于5月17日～9月21日在大豆根组织中出现，有2个明显高峰，最大密度在8月4日，每5 g根组织有435条。3龄和4龄幼虫于5月24日～9月21日在根组织中出现，有2个明显高峰，最大密度在8月4日，每5 g根组织有742条。结果表明，SCN在2014年诸城市大豆上可发生4代，但第1代发生量小而不明显，与第2代世代重叠明显；第3代发生量最大，第4代次之。大豆生长季前期土壤持续干旱是造成SCN前两代发生异常的主要原因。
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