pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-2-1-4 Articles Pod Breakdown Resistance in Peanuts1 D. M. Porter 2, K. H. Garren 2, and P. H. van Schaik 3 Plant Pathologists, Southern Region, ARS, USDA, Tidewater Research and Continuing Education Center, Holland Station, Suffolk, Virginia 23437 Formerly Research Agronomist at above address, presently Assistant Area Director, Western Region, ARS, USDA, Fresno, California 93727

1Cooperative investigations of the Southern Region, Agricultural Research Service, U. S. Department of Agriculture, and the Research Division, Virginia Polytechnic Institute and State University. Cotribution No. 284, Department of Plant Pathology and Physiology, Virginia Polytechnic Institute and State University, Blacksburg.

 1 1975 1 1975 2 1 15 18 American Peanut Research and Education Society 1975 American Peanut Research and Education Society Abstract

During 19 69–73, 13 commonly grown Virginia-type peanut (Arachis hypogaea L.) cultivars, 15 plant introductions. and two breeding lines were evaluated under field conditions for resistance to the pod breakdown fungi Pythium myriotylum and Rhizoctonia solani. Four cultivars—Early Runner. Florunner, Florigiant, and NC 17—having related pedigrees were consistently more resistant to infection by these two fungi. P.I. 341880 and P.I. 341885 and Florida breeding line F439–16–6 showed similar resistance to infection. Cultivars most susceptible to pod breakdown were NC 5, Va. 56R, Ga. 119–20 and Va. 72R. P.I. 343410 and a selection from P.I. 319178 were extremely susceptible to pod breakdown. Resistance to pod breakdown seems to have been derived from a cross between a small, white-seeded Spanish-type peanut and Dixie Giant, a large-seeded Virginia-type peanut. All resistant cultivars are related to this cross, whereas the susceptible cultivars lack these parental types in the pedigrees.

 Additional index words Pythium myriotylum; , myriotylum; , Rhizoctonia solani; , Arachis hypogaea. groundnut; , soil-borne fungi