Hartman G L, Kull L, Huang Y H
USDA, Agricultural Research Service, and Department of Crop Sciences.
Department of Crop Sciences, 70 EASB, 1101 W. Peabody, University of Illinois at Urbana-Champaign, Urbana 61801-4723.
Plant Dis. 1998 May;82(5):560-564. doi: 10.1094/PDIS.1998.82.5.560.
Sclerotinia stem rot (SSR) of soybean is an important disease in the northern soybean-production areas of the United States. In Illinois, the occurrence of SSR has been limited to the northern-most soybean-production areas. In this study, soybean fields in east-central Illinois were surveyed for incidence of SSR. Of 68 fields surveyed, 31 contained SSR. Of the fields with SSR, 25 had between 1 and 5% SSR incidence, while 6 fields had more than 5% SSR incidence. The pattern of the disease in one field was mapped, and the spatial distribution of SSR was aggregated with a Lloyd's index of 1.4. In addition to field incidence of SSR, seed lots suspected of being contaminated with Sclerotinia sclerotiorum sclerotia were obtained from the Illinois Crop Improvement Association. Sclerotia and seeds were separated, and seeds were germinated to determine the level of seedborne infection by S. sclerotiorum. Sclerotia were recovered from 71 of 81 seed lots. Most of the seed lots were from the north-central area of Illinois, but one seed lot was from Madison County in the southwestern area of the state, and three and six seed lots contaminated with sclerotia were from Iowa and Wisconsin, respectively. Sclerotia counts ranged from 0 to 363 per seed lot. Normal-appearing seeds from the 81 seed lots (100 to 200 seeds per lot) were tested for germination and incidence of seedborne infection by S. sclerotiorum. Eight seed lots had at least one infected seed, and the incidence of seed infection ranged from 0.07 to 0.1%. From 10 randomly selected seed lots of the 81, discolored, shriveled seeds were selected and germinated to determine the incidence of seedborne infection. Seed infection rates ranged from 0 to 70%. The occurrence of SSR throughout Illinois and the importance of seedborne infection as a source of inoculum dispersal need further documentation.
大豆菌核病（SSR）是美国北部大豆产区的一种重要病害。在伊利诺伊州，SSR的发生仅限于最北部的大豆产区。在本研究中，对伊利诺伊州中东部的大豆田进行了SSR发病率调查。在调查的68块田地中，31块含有SSR。在有SSR的田地中，25块的SSR发病率在1%至5%之间，而6块田地的SSR发病率超过5%。绘制了一块田地中该病的发病模式，SSR的空间分布通过劳埃德指数1.4进行汇总。除了田间SSR发病率外，还从伊利诺伊州作物改良协会获得了疑似被核盘菌菌核污染的种子批。将菌核和种子分离，使种子发芽以确定核盘菌的种传感染水平。从81个种子批中的71个中回收了菌核。大多数种子批来自伊利诺伊州的中北部地区，但有一个种子批来自该州西南部的麦迪逊县，分别有3个和6个被菌核污染的种子批来自爱荷华州和威斯康星州。每个种子批的菌核数量从0到363不等。对81个种子批（每个种子批100至200粒种子）中外观正常的种子进行了发芽测试和核盘菌种传感染发病率测试。8个种子批至少有一粒受感染种子，种子感染率在0.07%至0.1%之间。从81个中随机选择10个种子批，挑选出变色、皱缩的种子并使其发芽，以确定种传感染的发病率。种子感染率从0到70%不等。SSR在伊利诺伊州的发生情况以及种传感染作为接种体传播来源的重要性需要进一步记录。
