First report of mango malformation disease caused by Fusarium tupiense in Senegal.
Senghor A. L., Sharma K., Kumar P. L., Bandyopadhyay R.
Plant Disease 96 :1582
Abstract : In April 2009, severe outbreaks of a new disorder occured in mango orchards in the southeastern part of Casamance. Diseased plants showed abnormal growth of vegetative shoots with short thickened internodes and malformed inflorescence with short leaves interspersed among thickened sterile flowers that aborted early. To identify causal agent, floral and vegetative samples from asymptomatic mango plants were collected from Kolda district. Cultures were identified on the basis of spore characters on carnation leaf agar and colony morphology on PDA. Two isolates (I4 and I17) were similar to Fusarium mangiferae/F. sterilihyphosum/F. tupiense complex. To confirm the identity, genomic DNA was isolated from pure cultures of I4 and I17. Amplified products (241 bp) were purified and sequenced in both directions (GenBank Accession Nos. JX272929 and JX272930). A BLASTn search revealed 100% sequence identity with F. tupiense (DQ452858) from Brazil. To confirm Koch's postulates, 2-year-old healthy mango seedlings var. Keitt and Kent were inoculated by placing 20 µl conidial suspension on microwounds created in apical and lateral buds. Seven months after the inoculation, typical malformation symptoms were observed on vegetative parts on all inoculated plants, but not on control plants. F. tupiense was reisolated from symptomatic shoots of inoculated plants. Based on the morphological characteristics, sequence analysis, and pathogenicity test, the pathogen of mango malformation in Senegal was identified as F. tupiense. This is thought to be the first confirmed record in Senegal of mango malformation caused by F. tupiense.