Spilocaea pyracanthae causing leaf scab on loquat in Pakistan

Abstract

Abstract:Loquat is attacked by many phytopathogenic fungi.Among these Spilocaea pyracanthae is of economic importance. . In KPK, it is mainly cultivated in Mardan, Peshawar and Hari Pur districts while, in Punjab, it is mostly grown in the Pothowar region (Hussain et al. 2007). Loquat leaves have great significance from medicinal and nutritional point of view. In China, loquat leaves are being used as folk medicine for the treatment of pulmonary tuberculosis (Zhang et al. 2004). Loquat leaves are also used to cure various skin diseases, pain, inflammation, coughing, diabetes and liver disorders (Nishioka et al. 2002;Hamada et al. 2004;Sakuramata et al. 2004).There are numerous pathogens that attack loquat. Fire blight caused by Erwinia amylovora is a serious bacterial disease of loquat (Seymour 1965). Leaf spot incited by Diplocarpon mespili (= Entomosporium mespili) is another important disease of loquat (Batool et al. 2014) and several genera of subfamily Pomoideae of the Rosaceae family. The disease has proved itself capable of rendering an entire fruit crop unmarketable (Davidson 1985). Other pathogens reported to infect loquat include: Pseudomonas eriobotryae (canker), Phytophthora spp. (crown rot), Lasiodiplodia theobromae (= Diplodia natalensis -collar and root rot), and Colletotrichum gloeosporioides (anamorphic Glomerella) (anthracnose) (Crane and Caldeira 2006).Loquat scab is a very common disease in the Southern Italy, especially in Sicily, South Africa, around the Mediterranean basin, and in the eastern regions of North America on different hosts (Gardner and Raabe 1966;Raabe and Gardner 1972; Butt et al. 2015). Very little information is available in literature regarding loquat scab and the associated fungus Spilocaea pyracanthae. The fungus was first reported on loquat in 1909 (Smith 1909). The disease resembles pear and apple scabs in all aspects caused by Venturia pirina and V. inaequalis, respectively (Ohlendorf 1999). Loquat is highly susceptible to leaf and fruit scab especially during wet seasons when control measures are inadequate. Scabbed fruit is rendered unsuitable for market and results in economic loss (Tous and Ferguson 1996;Caballero and Fernández 2004). In Pakistan loquat is a neglected fruit tree and no attention has been paid to fungal pathogens associated with it. The current study is focused on the symptomatology of During extensive surveys of loquat orchards in 2013, spots were observed on leaves. The spotted leaves were brought to the laboratory for identification of disease symptoms and the associated pathogen. The color and shape of the spots were observed. For isolation of the pathogen, the spots were cut, and the surface was sterilized in ethanol and plated on autoclaved Potato Dextrose Agar (PDA) in 90 cm Petri plates. The plates were then incubated at 25 °C for the growth of the fungus. The fungus was purified from a single spore and identified on the basis of morphological characters (Schubert et al. 2003;Schubert and Braun 2005).The pathogenicity of the fungus was conf...

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“…Among all, few of them have a proper online catalogue describing the strain’s history, molecular evidence or status of a publication. Some published data is found having no clue about its disposition to any culture center ( 48 , 49 ). Due to the unavailability of the published strains at collection centers, their viability is doubtful.…”