pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-8-2-10 Articles Evaluating Peanuts for Resistance to Cylindrocladium Black Rot1 Ray O. Hammons 2, D. K. Bell 3, and E. K. Sobers 4 Supervisory Research Geneticist, USDA, Tifton, GA Associate Professor of Plant Pathology, University of Georgia College of Agriculture, Coastal Plain Stn., Tifton, GA Formerly Associate Professor of Plant Pathology, University of Georgia College of Agriculture, Coastal Plain Stn., Tifton, GA

1Contribution from the Departments of Agronomy and Plant Pathology, Univ. of Georgia College of Agriculture, Coastal Plain Stn., and U. S. Department of Agriculture, Agricultural Research Service, Southeast Area, Tifton, GA 31793-5401. The use of trademarks in this publication does not imply endorsement by the University of Georgia or the USDA, nor criticism of similar ones not mentioned.

 7 1981 8 2 117 120 15 9 1981 American Peanut Research and Education Society 1981 American Peanut Research and Education Society Abstract

Cylindrocladium black rot (CBR), a devastating disease of peanut (Arachis hypogaea L.), is caused by Cylindrocladium crotalariae (Loos) Bell and Sobers [perfect state, Calonectria crotalariae (Loos) Bell and Sobers]. No effective chemical control is known. Resistant cultivars would be the best way to control the disease. Two screening methods, employing sterile and nonsterile media, were developed and used for large-scale systematic screening of peanut genotypes for resistance. Results were reproducible with either method. The nonsterile method was more economical, required less handling, and permitted immediate transplanting of selections. Using both methods, we evaluated 929 different peanut lines from the world germplasm pool. Some 130 lines (14%) exhibited sufficient resistance to be reevaluated. After repeated screening by single-plant selection, six derived inbreds with greater resistance than the standard resistant Span-cross and NC 3033 peanuts were named CBR-R1 to CBR-R6 and released as germplasm lines for breeding use. They include representatives from three of the four botanical varieties of A. hypogaea.

 Key Words Arachis hypogaea; , Calonectria crotalariae; , Cylindrocladium crotalariae; , disease-resistance; , groundnut; , plant-diseases; , peanut breeding