Of the two antifungal antibiotics produced by Badllus subtilis F-29-3, the dipeptide compound bacilysin inhibits yeasts (and bacteria), whereas the formerly unknown fengymycin, a complex of closely related lipopeptide components, shows antibiotic activity against filamentous fungi.Bacilysin production, formerly known for a few strains only, could be demonstrated for all 12 wild-type cultures of Badllus subtilis tested during this study. The antibiotic also occurs in some strains of three other Badllus species considered as closely realted to B. subtilis.Members of the lipopeptide class of antifungal Badllus metabolites were formed by 8 of 12 Badllus subtilis-isolztes and several other Badllus strains.The antibiotics of F-29-3 were compared with antifungal metabolites of other Badllus isolates using TLC, agar-diffusion techniques and tests demonstrating the capacity of six lipopeptide and peptide preparations to protect rice seedlings from phytomycosis due to Rbizoctonia solani.Fengymycin proved to be different from the other compounds tested. It was less toxic to the test plants and protected them better from Rhizoctonia disease than the other antibiotics of the study did.

No abstract

Bacterial wilt caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is an important new disease of common bean (Phaseolus vulgaris) in western Canada. Both yellow and orange variants of the pathogen were found in the region. A controlled environment study was conducted to assess 124 common bean cultivars and lines from eight market classes for resistance to the yellow and orange variants of the pathogen, using the hilum injury/seed inoculation method. Results of the screening tests showed significant (P < 0.05) differences in resistance to bacterial wilt among the cultivars or lines. The great northern line L02E317, the great northern cultivar Resolute and pinto lines L02B662 and 999S-2A, were highly resistant to both variants of the pathogen, with disease severity indices of 0 on a rating scale of 0 (no wilt symptoms) to 5 (dead seedling). Resistant cultivars or lines were found among black, great northern, pink, pinto, small red and Flor de Mayo bean market classes. The study concludes that new bacterial wilt-resistant germplasm exists among Canadian bean cultivars and lines, and constitutes a valuable resource for breeding common beans for resistance to both yellow and orange variants of C. flaccumfaciens pv. flaccumfaciens. Materials and Methods Bean cultivars and linesA total of 124 common bean entries were used in the study, including 23 registered commercial cultivars and 101 breeding lines, of which 47 were from the bean breeding program at the Agriculture and Agri-Food Canada (AAFC) Research Centre in Lethbridge, Alberta, in cooperation with the AAFC Research Station in Morden, Manitoba, and 54 were from the www.blackwell-synergy.com J. Phytopathology 153, 245-249 (2005) Ó 2005 Blackwell Verlag, Berlin

Bacterial wilt, caused by Curtobacterium flaccumfaciens pv. flaccumfaciens (CFF), was a serious disease of common bean (Phaseolus vulgaris) in the United States in the early 1970s but was not reported for two decades after that time. Following this absence, the disease was reported again in the United States in North Dakota in 1995 and in Colorado, Nebraska, and Wyoming from 2004. In addition to the three coloured variants (yellow, orange and purple) of CFF reported in the United States in 1970s, a new pink variant of the pathogen was discovered in Nebraska in 2008. In Canada, the disease was reported in central Canada (Ontario) in the 1950s. The yellow and orange variants were found in western Canada in 2002, and the purple variant was found in 2006. These recent reports indicate a resurgence of bacterial wilt of bean in North America. The discovery of new variants suggests that the pathogen may be evolving. This minireview examines the resurgence of bacterial wilt of bean in North America, as well as its world distribution, symptoms, host range, and recent research progress in identification and detection, epidemiology, impacts, and methods of control of this disease. Résumé: Le flétrissement bactérien, causé par Curtobacterium flaccumfaciens pv. flaccumfaciens (CFF), était une maladie grave du haricot commun (Phaseolus vulgaris) aux États-Unis au début des années 1970, mais s'est faite plutôt discrète durant les deux décennies suivantes. Après cette absence, la maladie a été de nouveau signalée au Dakota du Nord en 1995 ainsi qu'au Colorado, au Nebraska et au Wyoming de 2004 à 2007. En plus des trois variantes chromatiques (jaune, orangé et pourpre) de la bactérie CFF rapportées aux États-Unis dans les années 70, une nouvelle variante rose de l'agent pathogène a été découverte au Nebraska en 2008. Au Canada, la maladie a été signalée en Ontario dans les années 50. Les variantes jaunes et orangées ont été trouvées dans l'Ouest canadien en 2002 et la pourpre y a été détectée en 2006. Ces récentes mentions indiquent qu'il y a résurgence du flétrissement bactérien chez le haricot en Amérique du Nord. La découverte de nouvelles variantes suggère que l'agent pathogène peut être en train d'évoluer. Ce minibulletin examine la résurgence du flétrissement bactérien chez le haricot en Amérique du Nord ainsi que sa répartition mondiale, ses symptômes, son spectre d'hôte et les dernières avancées des recherches relatives à l'identification et à la détection, à l'épidémiologie, aux répercussions de même qu'aux méthodes de lutte. Mots-clés : haricot, Phaseolus vulgaris, flétrissement bactérien, Curtobacterium flaccumfaciens pv. flaccumfaciens, biologie, épidémiologie, lutte, résistance aux maladies. Huang et al.: bacterial wilt on bean / Curtobacterium / mini-review 300

Indoor studies were conducted to determine the potential use of Pantoea agglomerans isolate LRC 8311 as a biocontrol agent for control of bacterial wilt of bean caused by Curtobacterium flaccumfaciens pv. flaccumfaciens. Soaking seeds of great northern bean cv. US1140 in a suspension of 3 · 10 8 cfu/ml P. agglomerans resulted in thorough endophytic colonization of the entire bean seedling from root to apical stem after 7 days, regardless of whether the inoculated seeds were hilum injured or not. Colonization of seedlings by P. agglomerans increased seedling height after 10 days, and had no negative effect on seedling emergence. Treatment of hilum-injured bean seeds of great northern bean cv. US1140 or navy bean cv. Morden003 with a mixture of P. agglomerans + C. flaccumfaciens pv. flaccumfaciens resulted in a high rate of colonization of seedlings by P. agglomerans, reduced frequency of infection by C. flaccumfaciens pv. flaccumfaciens, improved seedling emergence and height, and reduced disease severity, compared with seeds treated with the wilt pathogen alone. Application of P. agglomerans as a soil drench 24 h after planting was also effective in suppressing bacterial wilt in some instances, but was generally not as effective as seed treatment. The study suggests that seed treatment with P. agglomerans may be an effective and practical method for control of bacterial wilt of bean.www.blackwell-synergy.com J. Phytopathology 153, 608-614 (2005) Ó 2005 Blackwell Verlag, Berlin