Resistance in S. pennellii to Cladosporium fulvum Cke hat been reported previously (TGC 27, 1977;TGC 31, 1981; TGC 32, 1982). Recently, progenies from the cross (Hemus x Monalbo) x S. pennellii were tested with different races of C. fulvum. Results showed most of the lines possessed the combination Cf-2 and Cf-4. Some lines possessed only Cf-2 and in two lines (1063/77 and 1064/77) a gene like Cf-4.
From allelism tests (Table 1) it is evident that the genes in lines 1063/77 and 1064/77 are allelic with the gene Cf-4 in Purdue 135 (kindly provided by Dr. E.A. Kerr). These results suggest S. pennellii Corell as an additional source of the gene Cf-4 also reported as present in. L. hirsutum, L. peruvianum and L. piminellifolium.
Table 1. Results of allelic test after inoculation with race 1.2.3.
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Number of plants Ratio
Cross I S I : S
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(1063/77 x Purdue 135) F1 52 0 1 : 0
(1063/77 x Purdue 135) (x) 145 0 1 : 0
(1064/77 x Purdue 135) Fl 50 0 1 : 0
(1064/77 x Purdue 135) (x) 180 0 1 : 0
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