17 RESEARCH NOTES 'TGC REPORT No . 31, 1981 Most of our collections will be grown at Davis in 1981 for observation and stock increase, pending the success of which, supplies of seeds will be available for distribution . Stamova, L . and M . Yordanov Genetic study of the gene Cf - 2 for resistance to Cladosporium fulvum derived from different wild species . As reported previously (TGC 28, 1978) in progenies of crosses with S pennellii and L . minutum we found lines resistant to races 1 . 3 and 4 but susceptible to races 1 . 2 . 3 and 2 . 3 . 4of Cladosporium fulvum (Fulvia fulva) . In this material we observed autogenic necroses . Similar necroses appeared also in some lines originating from crosses with L . cheesmanii (pimpinellifolium form, Galápagos) and L . chilense . These lines were also resistant to races 1 . 3 but susceptible to races 1 . 2 . 3 and 2 . 3 . 4 . According to existing references (Langford 1948) autogenic necroses connected with resistance to Cladosporium fulvum are manifested in case the Cf - 2 gene from L . pimpinellifolium is combined with both recessive alleles ne/ne for necroses from the esculentum group . To compare the resistance factors in the above lines with the gene Cf - 2 from Vetomold, the allelic test was made . Furthermore, a separate nonreciprocal diallel cross was used with some of the necrotic lines . The results presented in the table show that it is possible that all these accessions contain the same resistant gene allelic to Cf - 2 in Vetomold . This will be studied further in F 3 and F 4 material and other lines from these crosses .