First Report of Alternaria alternata Causing Leaf Spot on Bruguiera gymnorrhiza in China

Abstract

2(Ch|). Pathotype 39(P,) was detected in small garden potato plots in the rainy mountainous area, a non-economically important potato-growing region where the old traditional cultivars of potato are cultivated without crop rotations. It seems, therefore, that where climatic conditions are suita ble for 5. endobioticum and the growing of slightly susceptible cultivars is possible, development of the new pathotype is favored.London planetrees (Platanus x acerifolia, syn. P. x hispanica), American sycamores (P. occidentalis), and oriental planes {P. orientalis) are widely planted as urban shade trees throughout Greece and many other countries. In June 2012, typical symptoms of a powdery mildew were detected on all sycamores (10 trees) along a central avenue of Heraklion (Crete, Greece), with the disease affecting approximately 80% of the leaves of all infected trees. In August 2013, similar symptoms were observed on 20% of the leaves of all three London planes in a small grove in the Vrysses area of Lasithi (Crete, Greece). In both cases, the disease was severe, with white superficial colonies developing amphigenously on leaves, twigs, floral peduncles, inflorescences, and fruits. The colonies were initially distinct and circular but gradually enlarged and often coa lesced to cover the entire leaf blade. Young leaves appeared curled and chlorotic, occasionally leading to defoliation. For the morphological de scription of the pathogen, samples from seven infected P. occidentalis and three P. x acerifolia trees were microscopically characterized. In all sam ples, the pathogen's mycelium was branched, septate, and hyaline, with lobed appressoria; conidiophores were erect, cylindrical, unbranched, and consisted of three to four (to five) cells; and conidia were single or in short chains (two to four), ellipsoid or doliiform, with a truncated base and rounded apex. Their dimensions were 24.3 to 48.6 x 15.8 to 27.9 pm (averaging 39.2 x 21.2 pm; n = 100), and their surfaces appeared reticulate. The teleomorph was never observed. Total fungal DNA was extracted from conidia harvested from affected leaves of one infected plant of each of P. occidentalis and P x acerifolia planes, and the ITS1-5.8S-ITS2 region was PCR-amplified with universal primers 18S-ITS1 and 28S-ITS2 (2) and sequenced (GenBank Accession Nos. KM068123 and KM068124, respectively). A BLASTn search of GenBank revealed 100% identity of both samples to Erysiphe platani strains described on P. orientalis in Greece (JQ365943) and P. occidentalis in Brazil (KF499270). Based on the morphological and molecular analyses, the pathogen was identified as E. platani (Howe) U. Braun & S. Takam. (formerly known as Microsphaera platani Howe) (1). To prove pathogenicity and fulfill Koch's postulates, 10 1-year-old seedlings of each of P. occidentalis and P. x acerifolia hosts were artificially inoculated with conidia obtained from naturally infected plants of the corresponding species, with two methods: (i) five plants of each host were dusted with conidia from diseased leav...

Characterization and toxicological potential of Alternaria alternata associated with post-harvest fruit rot of Prunus avium in China

“…According to several previous reports, all isolates of A. alternata isolated from several hosts produced dark olive green colonies on the PDA medium with dark brown conidia at 25 ± 2°C in a dark environment (Chen et al, 2018;Ghuffar et al, 2018;Alam et al, 2019), and the size of the conidia was 12-30-μm long and 7.5-12 μm wide (Gur et al, 2017;Chen et al, 2018;Moosa et al, 2019). Previous studies reported similar results that the length of conidia varied from 0 to 10 μm (Kumar et al, 2012;Lin et al, 2015). The causal organism of sweet cherry rot was preliminarily identified as A. alternata based on their morphological features (Simmons, 2007).…”

Nano Catalysis of Biofuels and Biochemicals from Cotinus coggygria Scop. Wood for Bio-Oil Raw Material

“…(CCS) was a deciduous tree and shrub of the lacquer tree family that was mainly distributed in southern Europe, Iran, Pakistan, northern India, southwestern China, North China, and Zhejiang. It is typically used as a shelter forest for water and soil conservation and for landscaping [ 1 , 2 , 3 , 4 ]. In addition, CCS contains various chemical components, such as flavonoids and gallic acid, and is also a traditional medicinal plant in China.…”

First Report of Alternaria alternata Causing Alternaria Brown Spot on Aralia elata in China

“…Therefore, the fungus was identified as A. alternata. A. alternata has a wide host range, including Ficus microcarpa, Bruguiera gymnorrhiza, and jujube (Bai et al 2015;Lin et al 2015;Yao et al 2015). This is the first report of A. alternata causing Alternaria brown spot on A. elata.…”