Study on the Genetics of Resistance to Leaf rust in some Advanced Lines of Wheat at Seedling Stage

Wheat leaf rust (Brown rust) caused by (Puccinia triticina) is a, worldwide major disease of wheat. In this study, three leaf rust isolate from Gorgan, were collected and determined their Avirulence and virulence formula with 39 near-isogenic lines. The results showed that these isolate were avirulence on plants with Lr1, Lr14a, Lr19, Lr25,, Lr23+ Lr28,Lr10+ genes while these isolate had virulence on plant with (Lr 22b, Lr 2a, Lr 2b, Lr 2b, Lr 2c, Lr 3, Lr 3ka, Lr 3bg Lr 9, Lr 10, Lr 11, Lr 12, Lr 13, Lr 14b, Lr 15, Lr 16, Lr 17, Lr 18, Lr 20,Lr 21, Lr 22a*, Lr 23, Lr 24, Lr 26, Lr29, Lr 30, Lr 32, Lr 33, Lr 34*, Lr 35*, Lr 36, Lr 37*, Lrb) genes. In order to evaluate of resistance to leaf rust, 122 advanced lines from Iranian regional program were tested at seedling stage with Gorgan pathotype in greenhouse condition. The experiment was conducted in randomized complete block design (RCBD) with three replications. The latent period (number of days from inoculation to appearance of the first uredia) and infection type were recorded by McIntosh et al; 1995 method. Analysis of variance showed significant difference between 122 genotypes for infection type and latent period in Gorgan, indicates that there are more diversity between genotypes with pathotupe Gorgan.. The results of analysis cluster lines showed division to thrre groups resistance and mid resistance and susceptible. Lines No. 23 and 78 were the more resistant and susceptible, respectively.