The Status of Cassava Bacterial Blight Caused by Xanthomonas campestris pv. manihotis in Trinidad

Abstract

Disease surveys conducted in Trinidad between 1985—1987 showed that Cassava Bacterial Blight (CBB) is present in all but one county of the country with disease severity ratings varying from 1—5 depending on day/night temperatures. Field and greenhouse screening identified varieties such as Point Fortin fine leaf and CMC 40 as being resistant whereas M col 22 was moderately resistant to susceptible. Using a combination of antiserum produced to whole cells of Xanthomonas campestris pv. manibotis and a broth enrichment technique, dissemination of the pathogen by flood water was confirmed. The pathogen was detected at distances of up to 300 meters from infected fields. The significance of this mode of pathogen dissemination in initiating primary infection in Trinidad is discussed.

Xanthomonas

“…Some of the recent reports are due to increased attention being paid to cassava as a major staple food crop. In some areas, its recent introduction and rapid spread have been demonstrated (Kwaje, 1982;Joseph and Elango, 1991), justifying strict quarantine measures on exchange of germplasm. In some areas, its recent introduction and rapid spread have been demonstrated (Kwaje, 1982;Joseph and Elango, 1991), justifying strict quarantine measures on exchange of germplasm.…”

Genome-wide analyses of LATERAL ORGAN BOUNDARIES in cassava reveal the role of LBD47 in defence against bacterial blight

“…CBB threatens food security in tropical regions and can generate up to 100 percent losses under favourable climatic conditions (CABI, 2015; FAO, 2008) [ 33 ]. The rapid spread of CBB in some cassava-producing regions and the emergence of new disease reports in regions where cassava is a staple crop highlight the necessity of developing novel methods to control this plant disease [ 30 , 34 – 36 ]. Cassava genome publication lays the groundwork for genome-wide analysis of new gene resources [ 37 ].…”

The role of type III effectors from Xanthomonas axonopodis pv. manihotis in virulence and suppression of plant immunity

“…This disease threatens food security in the tropics, where cassava constitutes a major staple food (CABI, ; FAO, ). Rapid dispersal of CBB in some cassava production regions (Joseph and Elango, ) and new disease reports in regions in which cassava is a staple crop (Kone et al ., ; Wonni et al ., ) underscore the importance of finding new ways to manage this plant disease (Lopez and Bernal, ). The management of this, as well as other, plant diseases would greatly benefit from a comprehensive knowledge of pathogen population dynamics and of the genetic bases for virulence in the pathogen and for resistance/susceptibility in the plant (Dangl et al ., ; Li Y et al ., ).…”