| Presence of possible rust resistance genes in genetic
stocks used in Indian wheat breeding programme B.S. MALIK and M.V. RAO IARI and Indian Council of Agr. Res., New Delhi, India Host parasite interaction which is highly specific and controlled by corresponding genes in host and the pathogen provides a basis on which information can be derived concerning either the host or the pathogen (BROWDER 1971). The utilization of specific genes for resistance is the major approach for resistance breeding against rust pathogen. The reaction of a genotype of host screened under controlled condition can be correlated with those lines carrying known genes for resistance to wheat rusts. On this basis probable genes in the host genotype are documented which latter can be confirmed by conventional genetic analysis i.e. test of allelism. In this article leaf rust effective genes in twelve wheat genetic stocks of groven resistance were identified by matching technique. Material and Methods Twelve rust resistant donors viz E 8643, E 8667, HS 1138-64, HB 117-107, V 156, HD 2009, CPAN 1283, CPAN 1436, CPAN 1437, CPAN 1517 and CPAN 1533 belonging to aestivum group were taken for these studies. Out of these, V 156 had genes from allied species i.e. Triticum timopheeve (Wis-245). These donors were screened against seventeen leaf rust virulences namely 10, 11, 12, 12A, 17, 20, 63, 77, 77A, 77B, 104, 104A, 106, 107, 108, 162 and 162A in the seedling stage under glass house (Table 2). Their seedling reactions were matched with the reactions of lines carrying known genes for leaf rust resistance (NAQVI 1976), (Table 3). Results and Discussion Documenting specific genes to rust resistance by conventional method is very laborious on account of crossing of each these donors with all the known Lr lines and testing the segregating population in the glass house against different rust virulences. Matching technique in wheat (BARTOS 1969) is based on the reactions of the set of isogenic lines which are genetically pure. In the present study apart from matching technique, the parentage/pedigree, tonomic evidences and geographical distribution of these donors were also taken into account for ascertaining the possibility of the effective genes (Table 1). On this basis, these donor varieties have been listed under two major groups. The first group comprising two varieties i.e. E 8643 and E 8667 resistant to all the leaf rust virulences tested. The second group comprising ten varieties could be further split in to the following distinct groups. 1. HB 117-107, CPAN 1283 and CPAN 1517 showing resistance to virulences 10, 11, 12, 12A, 17, 20 and 63. 2. HS 1138-6-4, HD 2009, CPAN 1437 and CPAN 1438 showing resistance to all virulences except virulences 12 and 77 complex. 3. CPAN 1533 resistant to all virulences except virulences 17 and 77 complex. 4. V-156 and CPAN 1436 resistant to all virulences except 10, 77 and 162. |
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