Vol. 11, Issue 2 (2022)

Author(s):
Tejpal Bajaya, RP Ghasolia, Mamta Bajya, Meera Choudhary, Manisha Shivran, Poonam Kumari and Jitendra Sharma

Abstract:
Groundnut (Arachis hypogaea L.) is an important legume crop of tropical and sub-tropical areas of the world. This crop suffers from several diseases but collar rot caused by Aspergillus niger van Teighem is one of the most important seed and soil borne diseases causing huge economic loss in India and abroad. In this study associated fungus was isolated on PDA medium and purified by using hyphal tip method from individual collar rot infected root of the plant collected from field showing maximum disease incidence during survey. On PDA, uniformly one type growth of fungus colony started black in colour and fungus rapidly covered the entire Petri plate within 72 hours. The hyphae were septate and hyaline more or less yellow in color. The colonies were black colored and reverse usually colorless. Conidiophores were hyaline, smooth, septate or non-septate. Conidia were globose to sub globose, dark brown to black with rough walled. Pathogenicity test of isolated and purified fungus was carried out with groundnut seeds following seed inoculation technique. On the basis of measurement and other morphological characters, the pathogen was identified as Aspergillus niger van. Tieghem. Thirteen domesticated crops and four weeds were artificially inoculated with highly virulent isolate (ANJP 04 isolate, isolated from Khejroli village of Jaipur district) of A. niger under pot house conditions during Kharif 2020. The result revealed that A. niger could produce visible symptoms on all tested plants of Fabaceae (cluster bean, cowpea, black gram, green gram, soybean), Poaceae (sorghum, maize, pearl millet), Pedaliaceae (sesame), Solanaceae (eggplant, tomato), Malvaceae (okra), Amaryllidaceae (onion) family and weeds of Papaveraceae (mexican prickly poppy), Asteraceae family (carrot grass) except plants of Zygophyllaceae (puncture vine weed) and Amaranthaceae (amaranthus) family were not produced any symptoms of collar rot disease.