Volatile metabolites fingerprinting to discriminate the major post harvest diseases of mango caused by Colletotrichum gloeosporioides Penz. and Lasiodiplodia theobromae Pat.

Volatile metabolites emitted from mango fruits artificially inoculated with two toxigenic fungi isolated from infected mangoes were profiled using gas chromatography/mass spectrometry. A noteworthy differential expression of volatile metabolites was observed. The chromatographic profiling study afforded a total of 88 different volatile compounds. Healthy uninjured mango fruits yielded 10 metabolites as a standard and uninoculated injured mango fruit emitted 23 compounds. Mango fruits inoculated with Colletotrichum gloeosporioides yielded 29 volatile metabolites; while that inoculated with Lasiodiplodia theobromae Pat. yielded 26 different volatile metabolites. Among them only 3 volatile compounds (2,6 ,10-trimethyltetradeca ne, crocetane and phellandrene) found consistently in fruits inoculated with C. gloeosporioides and L. theobromae. Whereas, 2-propylmalonic acid, 1,4 cyclohexadiene, 1-methyl-, boronic acid, cyclohexyl dimethoxymethyl, Acetic acid, methyl ester, and T hujol was common in fruits inoculated with C. gloeosporioides while fruits inoculated with L. theobromae had specific volatiles 1,3-dimethoxy-2-(methoxymethyl)-2 -methylpropa ne, Oxalic a cid, cyclohexyldecyl ester, Cyclopentanepropionic acid, 2,5-cyclohexadiene-1,4-dione, 2,6-bis(1,1-dimethylethyl)-, Carbonic acid, octadecyl phenyl ester, Spiro-1-(cyclohex-2-ene)-2'-(5'-oxabicyclopentane), 1',4',2,6,6pentamethyl-and stearic acid. This study suggests that these unique metabolites can be used as biomarkers to detect postharvest diseases or toxigenic fungal pathogens of mango at an early stage of disease progression and to successfully device strategies to protect the fruits.