The Korean Society of Crop Science J. Crop Sci. Biotech. 2010 (March) 13 (1) : 53 ~ 60 RESEARCH ARTICLE DOI No. 10.1007/s12892-010-0004-0 Genetic and Chemical Analyses of six Cowpea and two Phaseolus Bean species Differing in Resistance to Weevil Pest A. G. Abdel-Sabour 1* , H. A. Obiadalla-Ali 2 , K. A. AbdelRehim 3 1 Dept. of Genetics, Faculty of Agriculture, Sohag University, Sohag 82786, Egypt 2 Detp. of Horticulture, Faculty of Agriculture, Sohag University, Sohag, Egypt 3 Dept. of Botany, Faculty of Science, Sohag University, Sohag, Egypt Received: December 13, 2009/ Revised: February 27, 2010/ Accepted: March 30, 2010 Ⓒ Korean Society of Crop Science and Springer 2010 Abstract The objective of this work was to evaluate the genetic variability among six cowpea (Vigna unguiculata) cultivars differing in their resistance to Callosobruchus maculatus (F.) weevil. Two resistant bean cultivars were used to compare between the sensitive, moderate tolerant, and high tolerant cowpea cultivars. The differentiations were performed by using random amplified polymorphic DNA (RAPD) fingerprinting, protein concentration and organic and non-organic components in seed coat. Six polymorphic primers were identified, resulting in different informative bands. Based on polymorphic profiles, three clusters were formed. Clustering was mainly affected by the resistance to weevil pest. The sensitive cowpea cultivars were separated in one group, the moderate tolerant and high tolerant cultivars came in separate groups, and finally, the resistant bean cultivars separated clearly in one distinct group. The most interesting result was represented by concentration of total protein in the seed coat. The protein concentration in the resis- tant bean cultivars were approximately 50% less than concentration in each of the moderate tolerant and sensitive cultivars of cow- pea. Ferric ions were about 25% less than the moderate tolerant and sensitive cultivars. The concentrations of calcium and potassium in seed coats were higher in the resistant beans than in cowpea cultivars. Cobalt was about four times higher in resistant bean than in the sensitive and moderate tolerant cowpea cultivars, which may play a major role in seed resistance to weevil. Key words: Vigna unguiculata; Callosobruchus maculates (F.); RAPD fingerprinting; total protein; seed coat.. Abbreviations: Abs, absorbance; CTAB, cetyltrimethylammonium bromide; d.w., dry weight of sample, EDTA, ethylenediaminete- traacetic acid; h, hour; min, minute; TBE, Tris/Borate/EDTA; RAPD, Random Amplified Polymorphism DNA; U, unit; Vex, volume of extraction; Vsample, volume of sample. Old World legume cowpea, Vigna unguiculata (L.) Walp. is a tropical grain legume which plays an important nutritional role in developing countries of the tropics and subtropics, especially in Sub-Saharan Africa, Asia, Central and South America (Singh et al. 1997). Because of its high protein content (20-25%), cow- pea has been referred to as “poor man's meat.” Cowpea young leaves, pods, and peas contain vitamins and minerals which have fuelled its usage for human consumption and animal feeding (Nielsen et al. 1997). On the other hand, the New World legume common bean (Phaseolus vulgaris L.) and lima bean (Phaseolus lunatus) are a widely cultivated legume originating in the New World which have been domesticated both in Mesoamerica and South America and are currently cultivated in many tropical regions of the World (Smartt 1990). Callosobruchus maculatus F. (Coleoptera: Bruchidae), a pest of the seeds of Vigna unguic- ulata (L.) Walp. (Cowpea), do not attack the seeds of Phaseolus vulgaris (Applebaum et al. 1970). Bruchids are major threats to A. G. Abdel-Sabour ( ) abdelsabour.khaled@agr.sohag.edu.eg Introduction