ASIAN JOURNAL OF FORESTRY Volume 6, Number 2, December 2022 E-ISSN: 2580-2844 Pages: 97-125 DOI: 10.13057/asianjfor/r060206 Taxonomy, distribution and statistical ecology of black mildew fungi reported from Maharashtra state of India RASHMI DUBEY 1, ♥ , NEELIMA MOONAMBETH 1 , AMIT DIWAKAR PANDEY 1 Botanical Survey of India. Western Regional Centre, 7, Koregaon Road, Pune 411001, Maharashtra, India.  email: dr.rashmidubey@gmail.com Manuscript received: 1 June 2022. Revision accepted: 14 October 2022. Abstract. Dubey R, Moonambeth N, Pandey AD. 2022. Taxonomy, distribution and statistical ecology of black mildew fungi reported from Maharashtra state of India. Asian J For 6: 97-125. The Maharashtra state of India represents some of the best non-equatorial tropical forests in the world. It supports many endemic species of plants, animals, and microorganisms, especially in the Western Ghats, India. Moreover, a research project entitled "Foliicolous fungi of Maharashtra" was allotted by the Botanical Survey of India, Ministry of Environment, Forests, and Climate change, India, to carry out the mycological studies. As part of this project, ongoing studies were carried out on black mildew fungi of this state. The present studies offer a taxonomic account, distribution, and ecological parameters of 72 black mildew taxa collected from different areas of Maharashtra state of India. The present study provides three new records of fungi to India, 31 new host records to India, 40 new records of fungi to the Maharashtra state of India, and one new variety, viz., Asterina jasmini Hansf. var. koyani var.nov., depicted by checklist and Figures. In addition, a comprehensive table containing information on location, date of collection, name of the collector, and new records are given for ready reference. During this study, Meliola was the dominant genus with 35 species, whereas Meliolina mollis was the dominant taxon obtained from a maximum of 5 collections. More than 90% of black mildew species are collected from the Western Ghats Districts. In diversity indices, Gini-Simpson's was 0.9818, and Shannon's was 4.1668. Pielou's evenness index was 0.9743, causing true diversity, calculated as an effective number of species (64), to be less than observed species richness (72). Keywords: Asterinales, checklist, diversity indices, Meliolales, new records, taxonomy INTRODUCTION The state of Maharashtra is located in the northwestern part of peninsular India. It lies between 15°35′N and 22°02′ N latitudes and 72°36′E and 80°54′E longitudes. Maharashtra occupies an area amounting to 307731 km2, which comprises about 9.4% of the total area of India. The elevation in the state ranges from sea level to 1646 m. The state may be divided into three natural divisions according to physiography, viz., the narrow coastal strip of land, known as Konkan, lying between the Arabian Sea and the Western Ghats, the Western Ghats, and the Deccan Plateau. The Western Ghats is considered one of the 'Biodiversity Hotspots' of the world (Myers et al. 2000), showing high endemism in flora and fauna. From Dhule and Nandurbar in the north to the districts of Sindhudurg and Kolhapur in the south, the Western Ghats in Maharashtra passes 13 districts. Vegetation of the state was classified by Champion and Seth (1968) into the following five categories; (i) Tropical semi-evergreen forests, (ii) Tropical moist deciduous forests, (iii) Tropical dry deciduous forests, (iv) Tropical thorn forests, (v) Littoral and swamp forests. Black mildews are a group of black colony-forming parasitic fungi; most are obligate biotrophs, but a few are necrotrophs and host-specific with a very narrow host range. Since these fungi do not cause any appreciable pathogenicity in plants, not much attention has been paid to this group. However, due to higher temperatures in the parts infected by black mildew colonies, plant respiration is higher, causing reduced photosynthetic efficiency due to the lower efficiency of chlorophyll, leading to effects such as lower production of total sugar. Black mildews are especially abundant in the tropics (Hansford 1956) and mostly infest the dicotyledonous Angiosperms (>90%). In addition, they also infect monocotyledons, Gymnosperms, and Pteridophytes. Black mildew belongs to the family Meliolaceae, Asterinaceae, Englerulaceae, and Parodiopsidaceae in the Ascomycota. Order Meliolales contains more than 1,580 species (Hawksworth et al. 1995), most of which (1,400) are in the genus Meliola (Parbery and Brown 1986). Asterinaceous fungi are host specific because they must circumvent, tolerate and overcome the specific resistance factors of the particular host (Chandraprabha et al. 2011). The species concept of Asterinaceous fungi was based on the respective host plants and also on the morphological aspects of the fungus (Doidge 1942; Hansford 1946, 1956; Hosagoudar and Abraham 1996, Hosagoudar 2012). With its tropical climate and diverse flora, India provides favorable conditions for many black mildew fungi growth. Keys to the genera of black mildew fungi can be found in Muller and von Arx (1973), whereas species descriptions and illustrations are in monographic treatments by Hansford (1961, 1963). The biogeographical distribution of Meliolaceae members in India was described and illustrated by Hosagoudar in Meliolales of India, published in three volumes (Hosagoudar 1996, 2008, 2013). Asterinales of