Volatile metabolite profiling to detect and discriminate stem‐end rot and anthracnose diseases of mango fruits

Abstract

The volatile metabolites from the headspace gas of containerised mango ( Mangifera indica ) cv. Tommy Atkins fruits, surface wounded and inoculated with the two fungal anamorphic pathogens Colletotrichum gloeosporioides and Lasiodiplodia theobromae , or non-inoculated (controls), were profiled using a portable gas chromatograph/mass spectrometer to discriminate diseases of mango. Thirty-four compounds were detected relatively consistently among replicates. Several of these were disease/inoculation-discriminatory and were classified into three groups: (i) compounds unique to only one treatment; (ii) compounds common to two or more treatments, but not to all; and (iii) compounds common to all treatments, but varying in their abundance. Two compounds, 1-pentanol and ethyl boronate, were detected in L. theobromae-inoculated mangoes alone, while thujol was observed only in C. gloeosporioides-inoculated mangoes. Discriminant analysis models based on the abundance of significant mass ions and consistent compounds correctly classified diseases/inoculations in up to 100% of cases. The disease-discriminatory compounds and discriminant analysis models developed here have the potential to be used in the early detection of postharvest diseases of mango fruits after validation under commercial conditions.

A robust, simple, high‐throughput technique for time‐resolved plant volatile analysis in field experiments

“…These techniques permit high temporal resolution, but only limited resolution of analytes due either to a lack of mass spectral information (zNose®) or a lack of chromatographic separation and ion fragmentation (PTR-MS). Although these shortcomings may be partially ameliorated in new handheld GC-MS devices (Müller et al , 2005; Moalemiyan et al , 2006; Bednar et al , 2011), the need to transport, maintain, and provide power for such expensive, sensitive equipment in the field complicates their adoption. Furthermore, near-real-time analysis requires rapid chromatography, which cannot separate components of complex samples (Gaquerel and Baldwin, 2013); or may not include chromatography at all.…”

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

“…1-Pentanol and ethyl boronate were also reported to be unique for bacterial soft rot of carrot (Vikram et al, 2006). Similarly, in one (1)-pentanol and ethyl boronate, were detected in L. theobromae inoculated mangoes alone, while thujol was observed only in C. gloeosporioides inoculated mangoes (Moalemiyan et al, 2006). Acetyl hydrazide, propylcarbamate, propenyl bromide, acetone, 1-ethenyl-4-ethyl benzene, thiirane and 1-(methylthio)-E-1-propene were unique to onion bulbs artificially inoculated with Botrytis allii, while 3-bromo furan was specific to bulbs inoculated with E. carotovora subsp.…”

Biogenic Volatile Compounds for Plant Disease Diagnosis and Health Improvement

“… Beck et al (2015) showed that this method could differentiate between damaged and healthy Centaurea solstitialis in the natural environment. Portable GC-MS could efficiently discriminate between stem rot and anthracnose diseases of mango using 1-pentanol and ethyl boronate as marker volatiles for stem rot and thujol as a marker of anthracnose ( Moalemiyan et al, 2006 ). Aksenov et al (2014) coupled differential mobility spectrometry (DMS) with GC to detect citrus greening disease in plants at early stages of disease development.…”