Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Genetic analysis of resistance to bacterial leaf streak caused by Xanthomonas campestris pv. undulosa in bread wheat.

Abstract

The inheritance of resistance to bacterial leaf streak or black chaff of wheat (Triticum aestivum) was studied under field conditions, using an artificial epidemic of Xanthomonas campestris pv. undulosa. A complete series of crosses between 5 parents differing in reaction to X. campestris pv. undulosa was generated. Disease was recorded at two growth stages. No evidence of cytoplasmic effects was found from the comparison between reciprocal F1 crosses. The study of the F3 generations attested that 5 genes were involved in resistance to bacterial leaf streak. Separate analyses carried out for the 2 scoring dates were mutually consistent: genotypes, number of genes, and their action and relative importance were verified. The genes differed in strength of expression of resistance. One of the 2 strongest genes, Bls1, is present in all 3 superior parents, Pavon 76, Mochis T88 and Angostura F88. Resistance was not complete but proved to be stable over the season.