With climate warming in winter and planting structure adjustment, wheat stripe rust, Puccinia striiformis f.sp tritici(Pst)showed new occurring characteristics in China.Overwintering of Pst was studied by fixed-point investigation of wheat seedling stage in autumn and overwintering observation in early winter at 20 wheat fields of 7 villages of Kongtong District,Pingliang city,Gansu province during 2015~2017.The results showed that there was relative large quantity of Pst in the whole district in seedling stage in 2015,and average percentage of diseased plots and leaves were 50% and 0.17%. But in middle March in 2016, only 3 diseased leaves were found at Banwa of Panlong village, and none of them were found at seedling stage in autumn of 2016 and in spring of 2017. Based on meteorological conditions of the district from 2014 to 2017, average temperature in January was above -5 ℃, which accorded with the temperature condition of overwintering area; while rainfall and accumulated snow time were less from January to March. It was presumed that Pst could overwinter at warmer and sunning locations,and it was one of primary infection source in the region in spring.Also, functions of Pst require further study in the future.%近年来,随着冬季气候变暖及种植业结构的调整,小麦条锈病发生流行呈现出新的特点.为进一步明确小麦条锈菌在平凉市崆峒区的越冬情况,2015—2017年以崆峒区7个村镇20块麦田为试点,进行定点秋苗期调查和早春越冬观察.结果表明,2015年秋苗期(11月20日调查)全区菌源量相对较大,平均病田率和病叶率分别为50%和0.17%,翌年3月中旬调查,仅在草峰镇盘龙村半屲发现3片病叶,其余地方均未发现.2016年秋苗期和2017年春季全区均未发现.分析2014—2017年区内气象条件,1月份平均气温在-5℃以上,属条锈菌越冬区,但1—3月降水(雪)量和积雪时间相对偏少.初步推测小麦条锈菌仅在温暖向阳处越冬,是当地春季流行的初侵染源之一,但其作用尚需进一步研究探讨.
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