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Relationships Among Carbohydrate Content of Kernels, Condition of Silks After Pollination, and the Response of Sweet Corn Inbred Lines to Infection of Kernels by Fusarium moniliforme. J. M. Headrick, Department of Plant Pathology, University of Illinois, Urbana 61801, Present address: Monsanto Co., 700 Chesterfield Village Parkway, St. Louis, MO 63198; J. K. Pataky(2), and J. A. Juvik(3). (2)Department of Plant Pathology, University of Illinois, Urbana 61801; (3)Department of Horticulture, University of Illinois, Urbana 61801. Phytopathology 80:487-494. Accepted for publication 30 November 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/Phyto-80-487.

Twenty-two inbred lines were selected for carbohydrate analyses on the basis of a range of resistance to infection of kernels by Fusarium moniliforme. Relationships among the incidence of symptomatic and asymptomatic infection of kernels by F. moniliforme and the kernel content of individual sugars, total sugar, phytoglycogen, starch, and total carbohydrate were examined by linear regression analysis. Quantity and concentration of kernel carbohydrates were not related to infection of kernels by F. moniliforme. Asymptomatic infection of kernels by F. moniliforme was less for inbreds with silks that were green and actively growing at inoculation than for inbreds with green-brown or brown silks. Thus, browning and senescence of silks appeared to be important in initiating infection. Relationships among emergence of seedlings, carbohydrate variables, and infection of kernels by F. moniliforme were also examined by regression analyses, including principal factor regression. Infection of kernels by F. moniliforme and carbohydrate content of kernels were related to emergence of sweet corn inbred seedlings, yet much of the variation in emergence was not explained by these variables. Infection of kernels by F. moniliforme was the variable that was most highly related to emergence; however, symptomatic and asymptomatic infection accounted for only 39 and 30% of the variation in emergence, respectively. Many of the kernel carbohydrate variables were significantly related to emergence when the variation in emergence due to kernel infection was accounted for in multiple regression models. Based on these results, we do not expect that genetic improvement in the performance of sweet corn seedlings would be rapid if selection were based solely on the individual variables measured in this study.