~ 625 ~ The Pharma Innovation Journal 2021; 10(1): 625-630 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating: 5.03 TPI 2021; 10(1): 625-630 © 2021 TPI www.thepharmajournal.com Received: 03-11-2020 Accepted: 06-12-2020 SN Banne Department of Plant Pathology, College of Agriculture, Latur Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India Sunita J Magar Department of Plant Pathology, College of Agriculture, Latur Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India Shruti S Kadam Department of Plant Pathology, College of Agriculture, Latur Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India AP Suryawanshi Department of Plant Pathology, College of Agriculture, Latur Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India Corresponding Author: SN Banne Department of Plant Pathology, College of Agriculture, Latur Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, India Cultural and morphological characterization of isolates of Alternaria alternata (Fr.) Keissler, causing chrysanthemum leaf blight SN Banne, Sunita J Magar, Shruti S Kadam and AP Suryawanshi Abstract Fungal blights are among the major concern for limiting the cultivation and production of many ornamental and flowering plants. Chrysanthemum is an important cut flower with great export potential. However, it is infected by many pathogens in the protected cultivation. Diseased chrysanthemum samples were collected from chrysanthemum gardens, nurseries and farmers orchards in the Latur district for cultural and morphological characterization of Alternaria alternata. The collected isolates of A. alternata, from various varieties / hybrids of chrysanthemum were characterized, based on their mycelial growth, growth rate, colony appearance, colony shape and margin, sporulation and concentric zonation and morphological characters (mycelial width, conidia dimensions, beak length and numbers of vertical and horizontal septa). The highest colony growth was found in Ac-1, Ac-3 and ac-4 followed byAc-5. Excellent sporulation was found in isolates such as Ac-1, Ac-3, Ac-5 and Ac-9. Four isolates Ac- 10, Ac- 9, Ac-8 and Ac-7 showed large sized mycelial width ranged from 7.15-9.48 μm. Ac-9 and Ac-10 isolates was showed large sized conidia (42.17- 60.29 L X 9.40-11.77 W). Three isolates Ac-5, Ac-9 and Ac-8 showed large sized beak length ranged from 13.52- 15.29 μm, whereas horizontal septation ranged from 1-9 and vertical septation from 1-5. Keywords: Alternaria alternata, blight, cultural characters, morphology Introduction Chrysanthemum (Dendranthema grandiflora Tzvelev.) is a multi-use flower crop belonging to Asteraceae family and gaining more popularity as a cut flower, loose flower and pot plant. Chrysanthemum is commonly known as Queen of East, produces very attractive flowers of different shape, size and colours. It is an important commercial flower next to rose in the international florist’s trade and grown throughout the World (Kher, 1990) [6] . In India, chrysanthemum commercially growing major states are Karnataka, Tamilnadu, Maharashtra, Rajasthan, Madhya Pradesh and Bihar. In Maharashtra, chrysanthemum is grown on an area of 0.39 thousand ha. With the production of 1.65 thousand tonnes loose flowers and 0.05 thousand tonnes cut flowers (Anonymous, 2018) [2] . In Maharashtra, the leading districts in floriculture production are Nasik, Ahmednagar, Thane, Pune, Satara, Sangli and Nagpur. However, Ahmednagar district is specalized as growing district of the Maharashtra (Tupe et al., 2017) [17] . There has been a regular demand for chrysanthemum flowers throughout the year in our country. Hence, there is a great potential for the production of chrysanthemum on a commercial scale in India. However, it is difficult to get good quality exportable blooms, higher yields and long lasting post-harvest life of the cultivars under open conditions. The most important factors responsible for the threatened production of chrysanthemum flowers yield is by many diseases, such as, Alternaria leaf blight, Fusarium wilt, Septorial leaf spot, Ray speck disease, Pythium rot, Chrysanthemum rust, Bacterial blight, virus (viriod) and Nematode (Schmidt, 1958; Alfieri, 1968; Strider, 1985; Cook, 2001; Nishi et al., 2009 and Luong et al., 2010) [14, 1, 16, 3, 11, 9] . Alternaria is a genus of ascomycetous fungi. Alternaria species are known as major plant pathogens. There are 299 species in the genus Alternaria (Kirk et al., 2008, Nowicki-Marcin et al., 2012) [7, 12] . Therefore, it was decided to study in detail the morpho-cultural characters of the fungal pathogen.