Fungal Pathogens Associated with Aerial Symptoms of Avocado (Persea americana Mill.) in Tenerife (Canary Islands, Spain) Focused on Species of the Family Botryosphaeriaceae

Abstract

Fungi of the family Botryosphaeriaceae are considered responsible for various symptoms in avocado such as dieback, external necrosis of branches and inflorescences, cankers on branches and trunks, or stem-end rot of fruits. In recent years, these problems are becoming more frequent in avocado orchards in the Canary Islands (Spain). This work includes the characterization of fungal species involved in these diseases, which were isolated from avocado crops in Tenerife Island between 2018 and 2022. A total of 158 vegetal samples were collected, from which 297 fungal isolates were culture-isolated. Fifty-two of them were selected according to their morphological features as representative isolates of Botryosphaeriaceae, and their molecular characterization was carried out, sequencing the ITS1-2 region as well as the β-tubulin and the elongation factor 1-alpha genes. Five species of Botryosphaeriaceae were isolated, including Neofusicoccum australe, N. cryptoaustrale/stellenboschiana, N. luteum, N. parvum, and Lasiodiplodia brasiliensis. This is the first time that L. brasiliensis has been associated with avocado dieback and that N. cryptoaustrale/stellenboschiana has been cited in avocado causing symptoms of dieback and stem-end rot. However, it was not possible to assign our isolates unequivocally to N. cryptoaustrale or N. stellenboschiana even additionally using the rpb2 marker for their molecular characterization. Botryosphaeriaceae family seem to be involved in avocado dieback, in the premature fall of fruits during their development in the field and in post-harvest damage in Tenerife, but further studies are needed to clarify the fungal pathogens associated with symptoms in relation to phenological plant growth stages or less frequently observed.

Preventing microbe colonization on avocado (Persea nubigena var. guatemalensis) through metabiotic treatment, a promising postharvest safety improvement

“…Due to its high lipid and moisture content, low carbohydrate content, and non-acidic pH, previous studies have shown that avocados can be a good growth medium for pathogens ( FDA, 2018 ). Fungal infection, physical harm, lenticel breakdown, water loss, cold injury, or a combination of these causes may all contribute to this disease ( Hernández et al, 2023 ). Previous investigations carried out in different climatic zones in Peru indicate that black spot symptoms and nearby green tissue on the same fruit are likely related to physical damage, fungal invasion, and chilling injury ( Everett et al, 2015 ).…”

Duplex Real-Time PCR Assays for the Simultaneous Detection and Quantification of Botryosphaeriaceae Species Causing Canker Diseases in Woody Crops

“…However, this new scenario, together with the current climate change situation, have favored the increase in almond diseases [2][3][4]. Among them, woody canker diseases, associated with fungi of the Botryosphaeriaceae family, affect a great number of agronomically important woody crops such as olive, grapevine, avocado, blueberry, stone fruit, citrus and nut crops, including almond [5][6][7][8][9][10][11][12]. These diseases affect the trunk and branches of young and mature almond trees causing cankers, extensive gumming, dieback, discoloration and necrosis of internal tissues and, especially in severe cases and young trees, plant death.…”

Molecular Identification and Fungal Diversity Associated with Diseases in Hass Avocado Fruit Grown in Cauca, Colombia

“…Furthermore, abiotic factors such as physical damage and humidity have been related to lenticel damage [6]. Several investigations have been carried out in different countries to identify pathogens associated with diseases affecting avocado fruit, among which the genera Lasiodiplodia, Neofusicoccum, Fusarium, Penicillium, Aspergillus and Geotrichum have been described [7][8][9]. In Colombia, these problems have gained special attention due to their increased incidence in the field and the rejection of fruit in processing plants, which has generated significant economic losses.…”