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Genetic analysis of adult-plant resistance to leaf rust in five spring wheat genotypes

Navabi, A.

Genetic analysis of adult-plant resistance to leaf rust in five spring wheat genotypes - St. Paul, MN (USA) : American Phytopathological Society, 2003. - Computer File

Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0191-2917 Peer review Open Access

Inheritance of adult-plant resistance to leaf rust, caused by Puccinia triticina, was studied in the progeny of a one-way diallel cross involving five CIMMYT-derived adult-plant resistant wheat (Triticum aestivum) genotypes and a susceptible wheat ‘Avocet-YrA’. F1 progenies, F2 populations, F2-derived F3, and F4-derived F5 lines were field evaluated under artificial epidemics with leaf rust race MCJ/SP. Adult-plant resistance to leaf rust was incompletely dominant in crosses with the susceptible parent and was found to be controlled by additive interactions of Lr34 with at least two to three additional genes. Transgressive segregation giving rise to plants or lines with higher and lower levels of resistance than the parents was observed in all F2 and F5 derivatives of the resistant-parent intercrosses and suggested that, apart from Lr34, some of the other additive genes were nonallelic. Although specific combining ability was significant in some generations, general combining ability was found to be the major component of variation. Among generations, the estimates of the narrow-sense heritability of adult-plant resistance to leaf rust ranged from 0.67 to 0.97. Inheritance of adult-plant resistance to leaf rust, caused by Puccinia triticina Eriks., was studied in the progenies of crosses involving five adult-plant resistant wheat (Triticum aestivum L.) genotypes and a susceptible wheat ‘Avocet-YrA’. F1 progenies, F2 populations, F2-derived F3, and F4-derived F5 lines were field evaluated under artificial epidemics with leaf rust race MCJ/SP in two locations in Mexico. Adult-plant resistance to leaf rust was incompletely dominant in crosses with the susceptible parent and was found to be controlled by additive interactions of Lr34 with at least two to tree additional genes. Additive interactions of genes were found to be the major components of variation. Adult-plant resistance to leaf rust in the genotypes studied was found to be highly heritable. Plants or lines with higher and lower levels of resistance than the parents were observed in all F2 and F5 derivatives of the resistant-parent intercrosses and suggested that, apart from Lr34, some of the other additive genes were different. This indicated the possibility of incorporating these genes into new breeding lines. High levels of resistance in the resistant parents included in this study are expected to be durable.


Text in English

1943-7692 (Online) 0191-2917

https://doi.org/10.1094/PDIS.2003.87.12.1522


Heritability
Plant diseases
Disease resistance
Rusts
Wheat

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