ABSTRACT


Patricio Parodi P.1 y Ralph M. Caldwell1
 

A diallel cross between the resistant leaf rust differential varieties Malakof, Carina, Brevit, Webster and Loros, and susceptible Axminster, was tested in the F1 F2 and F3 generations and in the F1 ef test-crosses to Axminster, for their seedling reaction to Puccinia recondita f. sp. tritici, Rob. ex Desm., races 1, 2 and 15.
Progeny behavior indieated that two independently inherited genes gm'ern resistance to these three races of leaf rust. One of these genes is carried by Malakof, and is completely dominant. The second gene is commen to Carina, Brevit, Webster and Loros, being dominant in Carina, Webster and Loros, and incompletely dominant in Brevit. The gene in Malakof seems to be Lr1. The tentative symbol LrA is assigned to the gene in Carina, Webster and Loros. The symbol LrA1 is also tentatively assigned to the non-identical allele in Brevit.

Keywords:
1 Ingeniero Agrónomo M. S., Proyecto Trigo, Estación Experimental La Platina,. Instituto de Investigaciones Agropecuarias.