Windham G L, Williams W P
USDA-ARS, Crop Science Research Laboratory, P.O. Box 5367, Mississippi State, MS 39762.
Plant Dis. 1998 Mar;82(3):281-284. doi: 10.1094/PDIS.1998.82.3.281.
Field studies were conducted for 2 years in Mississippi to monitor maize kernel infection and aflatoxin accumulation caused by Aspergillus flavus at various times during the growing season. Hybrids resistant and susceptible to A. flavus were compared to determine temporal differences in infection and aflatoxin levels. The resistant hybrids tested were Mo18W × Mp313E, Mp420 × Tx601, and SC54 × SC76; and the susceptible hybrids tested were GA209 × Mp339, Mp307 × Mp428, and Mp68:616 × SC212M. The top ear of each plant was inoculated with a suspension containing A. flavus conidia at 7 days after midsilk (50% of the plants in a plot had silks emerged) using the side needle technique. Inoculated ears were harvested 35, 42, 49, 56, and 63 days after midsilk to determine kernel infection by A. flavus and aflatoxin contamination. Differences in aflatoxin levels between resistant and susceptible hybrids occurred in all harvest dates. However, significant differences between resistant and susceptible hybrids for kernel infection were not observed until 42 days after midsilk. Differences between resistant and susceptible hybrids occurred for kernel infection and aflatoxin concentrations 49, 56, and 63 days after midsilk. Incidence of kernel infection (8.1% for GA209 × Mp339) was the highest 49 days after midsilk, and aflatoxin concentrations (510 ng/g for Mp307 × Mp428) were the highest 63 days after midsilk. Maximum differences between resistant and susceptible hybrids for aflatoxin levels were observed 63 days after midsilk. Two of the resistant hybrids, Mo18W × Mp313E and Mp420 × Tx601, had significantly less aflatoxin than the three susceptible hybrids 63 days after midsilk.
在密西西比州进行了为期两年的田间研究，以监测生长季节不同时间由黄曲霉引起的玉米籽粒感染和黄曲霉毒素积累情况。比较了对黄曲霉有抗性和敏感的杂交种，以确定感染和黄曲霉毒素水平的时间差异。所测试的抗性杂交种为Mo18W×Mp313E、Mp420×Tx601和SC54×SC76；所测试的敏感杂交种为GA209×Mp339、Mp307×Mp428和Mp68:616×SC212M。在吐丝中期后7天（小区内50%的植株吐丝），使用侧针技术对每株植物的顶部果穗接种含有黄曲霉分生孢子的悬浮液。在吐丝中期后35、42、49、56和63天收获接种的果穗，以确定黄曲霉对籽粒的感染和黄曲霉毒素污染情况。在所有收获日期，抗性和敏感杂交种之间的黄曲霉毒素水平均存在差异。然而，直到吐丝中期后42天，才观察到抗性和敏感杂交种在籽粒感染方面的显著差异。在吐丝中期后49、56和63天，抗性和敏感杂交种在籽粒感染和黄曲霉毒素浓度方面出现差异。籽粒感染发生率（GA209×Mp339为8.1%）在吐丝中期后49天最高，黄曲霉毒素浓度（Mp307×Mp428为510 ng/g）在吐丝中期后63天最高。在吐丝中期后63天，观察到抗性和敏感杂交种在黄曲霉毒素水平上的最大差异。在吐丝中期后63天，两个抗性杂交种Mo18W×Mp313E和Mp420×Tx601的黄曲霉毒素含量明显低于三个敏感杂交种。
