Rose (Rosa sp.) is an important floricultural crop cultivated in the Karnataka state of southern India. A field survey conducted in Devanahalli, Bangalore rural during October revealed rose plants (cv. Arka Pride) showing dieback symptoms with a disease incidence of 7% in an area of 30 hectare rose field.
Dieback is characterized by the development of necrotic lesions that started at the tip of shoots and progress downwards, leading to the death of young shoots. Pycnidia were found on young shoots showing necrotic lesions. Dieback affected shoots (n=10) were surface sterilized with 2% NaOCl for 2 min, rinsed thrice in sterile distilled water, and plated on potato dextrose agar (PDA) medium amended with chloramphenicol (40mg/L). The plates were incubated at 28±2 °C and pure cultures were obtained by hyphal tipping. Fungal colonies with white aerial mycelia along with pycnidia were observed on eight samples.
Colony growth rate was at 4.2 ± 0.4 mm/day with an average colony diameter of 47.2 ± 3.8 mm after 7 days (12/12 h light and dark period). Pycnidia were solitary and globose. Conidia were hyaline, single-celled ellipsoid to fusiform, measured 12.4 – 16.78 × 3.2 – 5.1 μm (n=50). Based on cultural and morphological features, the fungus was identified as Coniella granati
Read the complete research at www.researchgate.net.
S, Mahadevakumar & Y S, Deepika & Amruthesh, Kestur & Lakshmidevi, Nanjaiah. (2021). First Report of Coniella granati Associated with Die-back of Rose (Rosa sp.) in India. Plant Disease. 10.1094/PDIS-08-21-1816-PDN.