Weeds Harbor Fusarium Species that Cause Malformation Disease of Economically Important Trees in Western Mexico

Abstract

Mango malformation disease (MMD) caused by Fusarium spp. is an important limiting factor in most production areas worldwide. Fusarium mexicanum and F. pseudocircinatum have been reported as causing MMD in Mexico. These two pathogens also cause a similar disease in Swietenia macrophylla (big-leaf mahogany malformation disease or BLMMD) in central western Mexico, while F. pseudocircinatum was recently reported as causing malformation disease in Tabebuia rosea (rosy trumpet) in the same region. These studies suggest that additional plant species, including weeds, might be hosts of these pathogens. The role that weed hosts might have in the disease cycle is unknown. The objectives of this work were to recover Fusarium isolates from understory vegetation in mango orchards with MMD, identify the Fusarium isolates using DNA sequence data, and determine if F. mexicanum is capable of inducing disease in the weedy legume Senna uniflora (oneleaf senna). Additional objectives in this work were to compare Fusarium isolates recovered from weeds and mango trees in the same orchards, by characterizing their phylogenetic relationships, assessing in vitro production of mycotoxins, and identifying their mating type idiomorph. A total of 59 Fusarium isolates from five species complexes were recovered from apical and lateral buds from four weed species. Two of the species within the F. fujikuroi species complex are known to cause MMD in Mexico. Trichothecene production was detected in five isolates, including F. sulawense and F. irregulare in the F. incarnatum-equiseti species complex and F. boothii in the F. sambucinum species complex. Both mating types were present among mango and weed isolates. This is the first report of herbaceous hosts harboring Fusarium species that cause mango malformation in Mexico. The information provided should prove valuable for further study of the epidemiological role of weeds in MMD, and help manage the disease.

Identification of New Fusarium sulawense Strains Causing Soybean Pod Blight in China and Their Control Using Carbendazim, Dipicolinic Acid and Kojic Acid

“…Although isolates NJC31, NJC32 and NJC33 were found to contain several trichothecene biosynthesis genes, further chemical analyses are necessary to confirm the presence of trichothecenes in the secretions of and their structures. The ability of F. sulawense to produce trichothecenes was previously reported by Montoya-Martinez et al [ 25 ]. As far as we know, F. sulawense has never been reported to synthesize zearalenone.…”

“…F. sulawense was also found to cause rot on papaya, leaf spot on mango and blight on plums in China [ 41 , 42 , 43 ]. This species was identified as the causal agent of malformations on Swietenia macrophylla and head blight of wheat in Mexico [ 25 , 27 ]. F. sulawense was discovered to be the cause of sesame stem rot in Pakistan [ 44 ], and rice sheath rot in Indonesia [ 45 ].…”

“…F. incarnatum-equiseti species are known to synthesize mycotoxins, such as zearalenone and trichothecene [ 22 , 25 , 54 ]. Although isolates NJC31, NJC32 and NJC33 were found to contain several trichothecene biosynthesis genes, further chemical analyses are necessary to confirm the presence of trichothecenes in the secretions of and their structures.…”

“…Fumonisins, which are synthesized by some Fusarium strains, cause fatal livestock diseases and are considered potentially carcinogenic mycotoxins for humans [ 24 ]. F. sulawense , among other species, has been reported to synthesize mycotoxin trichothecene, which can cause breathing problems and lung inflammation [ 25 ].…”