Pathogenic and genetic variation in Xanthomonas axonopodis pv. Phaseoli and its fuscans variant in Southern Africa

摘要: Common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli and its fuscans variant, X. var. is a widespread disease of dry beans in South Africa. Variation within pathogen populations has been reported order to breed for resistance it important investigate whether variation exists the local population. One hundred forty three common isolates from 44 localities four countries, were inoculated onto eight Phaseolus acutifolius lines that differentiate between pathogenic races. This differential set was expanded include resistant genotypes, XAN 159, GN #1 Nebr. sel 27, Wilk 2, 6, Vax 4, 5 6 cv. Teebus as susceptible check. Genetic nine selected Xap Xapf non-pathogenic isolate, studied using RAPD AFLP analysis. Genotypes all isolates, while 27 susceptible. Isolates varied aggressiveness on Teebus; however, reaction differentials indicated all, but one grouped what race 2. Thus, results based majority suggest absence different However, distinct recorded single may prove represent another, yet unrecorded, this pathogen. Both analyses revealed high frequency DNA polymorphism among could distinguish Xap, isolate. Differences demonstrate these are two groups bacteria.