Fruit Rot Caused by Penicillium italicum on Lemon (Citrus aurantifolia) in Colima, Mexico

Abstract

Postharvest rotting caused by Penicillium italicum Wermer is responsible for significant economic losses of orange (Citrus sinensis (L.) Osbeck) and lemon (C. limon Burm. f.) worldwide, but until now was not described on lemons (C. aurantifolia (Chistm.) Swingle) in Mexico. During May 2002, we analyzed 400 fruits of lemon collected in the state of Colima, which is the most important lemon producer in Mexico. Rotting and softened areas covered with a white mycelium and blue conidia were observed on approximately 30% of the fruits. Affected tissue was plated onto potato dextrose agar (PDA) for fungal isolation and identification. Following the morphological criteria (1) and the internal transcribed spacer 1 (ITS1), 5.8S, and ITS2 region of the ribosomal DNA (2) (GenBank Accession No. DQ991463), the fungus was identified as P. italicum and deposited in the Colección Microbiana y de Cultivos Celulares CINVESTAV-IPN, México. For the pathogenicity test, the fungus was grown on PDA for 1 week. Four drops (15 μl each) of a sterile water suspension of 106 conidia per ml were placed in four wounds of 3 × 3 × 3 mm produced with a scalpel on the fruit surface. Five plastic boxes with six fruits each were placed in an environmental chamber at 12°C and 90% relative humidity. After 10 days, all fruit rotted in a similar way as naturally infected fruit on trees. Control fruits inoculated with sterile distilled water were symptomless. The test was repeated and the results were similar, confirming Koch's postulates. To our knowledge, this is the first report describing the isolation and pathogenicity of P. italicum on lemon (C. aurantifolia) in Colima, Mexico, which may have important implications in fruit quality and storage. References: (1) Z. Kozakieweicz. IMI Descriptions of Fungi and Bacteria. 155, Sheet 1548, 2002. (2) M. J. Pianzzola et al. Plant. Dis. 88:23, 2004.

Electrospun Nanofiber Mats as “Smart Surfaces” for Desorption Electrospray Ionization Mass Spectrometry (DESI MS)-Based Analysis and Imprint Imaging

“…The major metabolite identified (Figure ) was at m / z 404, the tandem mass spectra of which confirmed it as Ochratoxin A (OTA). It is a toxic metabolite released by the fungus Penicillium digitatum, the causal agent of fruit rot of lemon . Several metabolites, including limonene ( m / z 137) and limonene-diol ( m / z 171), released by the degrading lemon tissue could also be identified (Table S1, Supporting Information).…”

“…It is a toxic metabolite released by the fungus Penicillium digitatum, the causal agent of fruit rot of lemon. 47 Several metabolites, including limonene (m/z 137) and limonene-diol (m/z 171), released by the degrading lemon tissue could also be identified (Table S1, Supporting Information). Direct imaging of microbes from agar plates was reported, 48 but using nanofiber mat eliminates background interference and restrains the microbial contamination.…”

Selective Sensing and Imaging of Penicillium italicum Spores and Hyphae Using Carbohydrate–Lectin Interactions

“…3 Numerous studies have been performed to eliminate and prevent the growth of P. italicum in citrus species 1,2 but there have been no studies reported on the detection of P. italicum species other than phylogenetic approaches. 4 In contrast, automated vision systems are applied to monitor infected citrus plants during storage and transportation, 3 which are unable to detect species specific monitoring of the presence of P. italicum. Moreover, conventional culture methods are time- consuming while other approaches such as ELISA, PCR, confocal and fluorescence microscopy, and SPR are not easily accessible and may sometimes be labor-intensive and costly.…”

“…italicum in citrus species , but there have been no studies reported on the detection of P. italicum species other than phylogenetic approaches . In contrast, automated vision systems are applied to monitor infected citrus plants during storage and transportation, which are unable to detect species specific monitoring of the presence of P.…”