First Report of Fusarium mangiferae Causing Mango Malformation in China

Abstract

Verticillium wilt caused by the fungus Verticillium dahliae is found worldwide and attacks a wide range of plants. In the summer of 2001, a wilt disease of Amygdalus communis (sweet almond) cultivated in the Xinjiang municipality in China was first observed. The characteristic symptoms of typical wilt included wilt of leaves and twigs, and brownish discoloration of vascular tissues. Ultimately, the branches and entire trees wilted and died. To identify the causal agent, both traditional and PCR-based methods were attempted. In 2004 and 2005, a Verticillium sp. was isolated from the xylem of diseased branches on potato dextrose agar (PDA). The fungus produced dark colonies on PDA, produced rotiform conidiophores with 2-4 layers, one-celled colourless olivary conidia, and small black microsclerotia. It was identified as V. dahliae based on morphological characteristics according to the description of Smith (1965). Ribosomal DNA (regions ITS1, 5·8S rDNA and ITS2) was amplified and sequenced (GenBank Accession No. EU109532). Sequence analysis revealed that the fungus isolated from A. communis is identical to a Greek strain of V. dahlia (GenBank Accession No.AF104926). Each of six seedlings of A. communis , approx. about 20 cm high in sterile soil, was inoculated by injecting 20 μ L single-conidial suspension containing 1 × 10 6 conidia mL-1 into the base of the stem. The inoculated seedlings were incubated at 25 ° C. Water-soaked lesions appeared on the leaves of all of the inoculated seedlings after 4 days and then dark brown lesions appeared around the injected sites and spread rapidly upwards. The inoculated seedlings wilted and died after 7 days. The pathogen was reisolated from the inoculated stems. Control seedlings, inoculated with an equal volume of sterile water, remained healthy. The fungus was previously recorded in Xinjiang municipality and other provinces in China infecting many Rosaceae and Malvaceae plants (Tai, 1979), but this is the first report of V. dahliae associated with wilt of A. communis in China. References Smith HC, 1965. The morphology of Verticillium albo-atrum , V. dahliae , and V. tricorpus .

In vitro: Response of plant growth regulators and antimalformins on conidia germination ofFusarium mangiferaeand incidence of mango malformation

“… 12 Recently, F. mangiferae was found to be associated with mango malformation. 13 Here, we morphologically characterized Fusarium sp from mango cv, Dashehri ( Fig. 1A–D ) and found that features (light purple plus white colony colors, shape and size of microconidia and macroconidia, partitionate hyphae with septa and absence of chlamydospores) were in accord with the reported standard features of species F. mangiferae .…”

“…More than one species of Fusarium were reported to be involved in the disease 12 . Recently, F. mangiferae was found to be associated with mango malformation 13 . Here, we morphologically characterized Fusarium sp from mango cv, Dashehri ( Fig.…”

Characterization of Fusarium Species Associated With Mango Malformation Disease in Southern Senegal

“…Isolate 26 morphologically resembled F. subglutinans and its comparison in the database showed 99.44% similarity with F. subglutinans, F. sterilihyphosum and F. proliferatum. These two species have already been associated with mango malformation disease around the world according to several studies (Steenkamp et al, 2000;Britz et al, 2002;Zhan et al, 2012;Freeman et al, 2014b) This result is probably due to the fact that the genus Fusarium is a genus that is evolutionarily recent and therefore unstable, hence the importance of the number of species and the variations between species on the same plant and from one plant to another in this genus.…”