First report of target spot on tomato caused by Corynespora cassiicola in Nepal

作者：Ram B. Khadka, Rabin Bhandari, Arbindra Rimal, Arjun Gaire, Surya Prasad Adhikari, S. Bhandari, Sarita Manandhar, Suraj Baidya · 发表于：New Disease Reports · 年份：2023 · DOI：10.1002/ndr2.12187 · 被引用次数：4 · 研究领域：Plant Pathogens and Fungal Diseases、Plant-Microbe Interactions and Immunity、Plant Pathogens and Resistance

Tomato (Solanum lycopersicum) is one of the most important vegetable crops in Nepal and is grown in high tunnels and open fields (Rawal et al., 2017). In June 2022, tomato plants having blighted lesions with concentric circles, yellow halos, and severely defoliated leaflets, with an incidence of c. 80%, were obtained from growers in the Panauti area of Kabrepalanchok district in the central hills of Nepal, an area of c. 3 ha. Samples were examined under a microscope with tape mounting and slightly curved to cylindrical, multiple pseudoseptate conidia resembling Corynespora cassiicola (Qi et al., 2011) were observed. Small pieces of infected leaves were surface disinfected with 1% sodium hypochlorite, washed twice with sterile water, and air-dried before being placed on acidified potato dextrose agar (PDA) plates for pathogen isolation. After five days incubation at 25°C with 12 hr light / 12 hr dark, grey to brown mycelia (Figure 1) with slightly curved cylindrical conidia were detected. Conidia (n = 30) were 105.8 μm (71.0- 142 μm) in length and 9.4 μm (7.2 -10.5 μm) in width, on average. The conidia were curved to straight or cylindrical in shape and formed in chains or singly (Figure 2). The specimen resembled C. cassiicola morphologically (Qi et al., 2011). Subsequently, pure cultures were obtained by culturing a single germinating spore on water agar plates before transferring to PDA plates. DNA was extracted from week-old mycelia of pure cultures using AMPure XP beads (...