Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0011-183X

Leaf rust, caused by Puccinia recondita f.sp. tritici, is an important disease of wheat (Triticum aestivum) worldwide. The Lr34 gene is known to confer durable resistance. The effects of Lr34 on grain yield and other traits in the absence and presence of leaf rust were evaluated. Jupateco 73R and Jupateco 73S (near-isogenic reselections from the Mexican spring wheat cultivar Jupateco 73 for the presence and absence of Lr34, respectively) and 22 random inbred F6 lines, 11 with and 11 without Lr34 (derived from the cross Jupateco 73R/Jupateco 73S), were planted in replicated field trials during the 1992-93 and 1993-94 seasons in northwestern Mexico. The mean grain yield of Jupateco 73R was 5.9% lower (P <0.05) than that of Jupateco 73S in protected plots in the 1992-93 experiment. Significant reductions (P <0.05) were also observed for biomass, grains per spike and grains m-2. Significant (P <0.01) reductions of 5% in mean grain yield and 3.7% in mean grain weight were again evident in one of the two experiments sown during the 1993-94 season. Comparison of grain yield in protected and non-protected treatments indicated that though leaf rust could significantly (P <0.01) reduce grain yield by approximately 15% in the presence of Lr34, the reductions in the absence of Lr34 were substantially higher and ranged from 42.5 to 84% depending on planting date and year. Reductions in all other traits were also significantly higher in the absence of Lr34. It is concluded that although the presence of Lr34, which is linked with leaf tip necrosis of adult plants, may carry a slight yield penalty in some disease-free environments, its use in leaf rust prone areas could provide substantial protection to grain yield and other traits

Global Wheat Program

English

9705|Crop Science Society of America (CSSA)|EE|R97ANALY|Maria|Fdo|1

INT0610

CIMMYT Staff Publications Collection

Serials Collection