VIEW ARTICLE

Specificity of the Puccinia recondita f. sp. tritici: Triticum aestivum ‘Bulgaria 88’ Relationship. L. E. Browder, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Plant Pathology Department, Kansas State University, Manhattan, Kansas 66506; Phytopathology 63:524-528. Accepted for publication 1 November 1972. DOI: 10.1094/Phyto-63-524.

Infection-type (IT) data obtained by inoculating Triticum aestivum ‘Bulgaria 88’ (B88) and an experimental line, ‘Purdue selection 45’ (PD45) with 25 cultures of Puccinia recondita f. sp. tritici indicated specificity in the relationship of B88 and P. recondita f. sp. tritici. All cultures except one produced a low IT on B88 compared to the IT produced on PD45 by the same cultures; two distinctly different low ITs were observed within those produced by the 24 cultures. The other culture produced a higher IT on B88 than on PD45. These data indicated an hypothesis that B88 has two genes for low reaction to P. recondita f. sp. tritici. A comparison study of B88 with host-lines having Lr1, Lr2A, Lr2B, Lr2C, Lr2D, Lr3, Lr9, and Lr11 indicated that one of the hypothesized genes for low reaction in B88 is Lr11; these comparisons provided no evidence that the other hypothesized gene is any of the known named genes for low reaction. A further study comparing B88 with the host-line having Lr11 [LR11 (Wichita)] with other cultures and in three environments supported the hypothesis that B88 has Lr11. Infection types produced on B88 and LR11 (WI) were identical in a 15-20 C growth chamber environment and were similar, although different, in two greenhouse environments. These results imply that the resistance of B88 is specific rather than general.