Relation of Flag Smut Incidence to Spike Type in Wheat Isolines1
- R. E. Allan and
- J. A. Pritchett2
Incidence of flag smut [Urocystis agropyri (Preuss) Schroet.] was indirectly related to the club spike trait in F6 and F7 isolines of the population ‘Suwon 92’/8* ‘Omar’ (Triticum aestivum L. em Thell.). Paired comparisons between isolines showed that the club types averaged 3.0 and 12.2% more smut than lax types at two different field sites in 1971. The club sib was equal to or more heavily smutted than the lax sib in 31 of the 40 comparisons. The club lines averaged 10.5% more smut than their lax sibs in a replicated test in 1973. The relationship between the C allele and increased severity of flag smut appeared to be indirect, since no linkage or pleiotropism was detected between the two characteristics from observations on two crosses. In addition, percentage of flag smut was not significantly different between the two spike types at one site. The C allele reduces rates of seedling growth and emergence, and delayed emergence may increase the opportunity for the wheat seedling to become infected by the pathogen. Club genotypes can potentially suffer greater losses from flag smut than lax genotypes. In the development of club cultivars, breeders should especially emphasize high, stable flag smut resistance.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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