Vol. 6, Issue 6 (2017)
Symptomatology, proving pathogenicity and standardization of inoculum density of Fusarium oxysporum causing wilt of fenugreek
Author(s): Rani N, Yashoda R Hegde and Nargund VB
Fenugreek (Trigonella foenum graecum L.) is an important seed spice, originated in South-Eastern Europe belonging to the family Fabaceae. Wilt of fenugreek caused by Fusarium oxysporum, exhibited symptoms like stunting of the plants, gradual yellowing of lower leaves, drooping, epinasty, drying of leaves, vascular discoloration and ultimately death of entire plant was noticed. In Rhizoctonia solani infected plants showes yellowing, drying of leaves, discolouration of roots and complete decaying of tap and lateral root system was noticed. Finally death of entire plants. The sclerotium wilt symptoms appeared as yellowing of lower leaves, stunted growth, finally death of plant. This is the new report of the Sclerotium wilt of fenugreek. Fusarium oxysporum colonies were cottony white to dark pink. Mycelium was septate and hyaline and produced both macro and microconidia. Macroconidia were moderately curved, stout, sickle shaped, usually 1-3 septate. R. solani produced black colour colony, dense, radiating luxurious mycelial growth and right angle branching.
S. rolfsii. produced the silky white, dense, radiating mycelial growth on potato dextrose agar medium. Initiation of sclerotial bodies were obtained from sixth day after inoculation. Pathogenicity test of F. oxysporum was observed for symptom expression. Death of the plant was observed at 28 days after sowing. In Rhizoctonia solani inoculated plants exhibited foliar yellowing and stunting of the plants at 12 days after sowing. Death of plants was noticed at 14 days after sowing. In S. rolfsii yellowing of lower leaves was noticed at 14 days after sowing and finally death of the plants was noticed at 18 days after sowing. The fungus was reisolated from infected plant tissue and compared with the original culture which yielded the Fusarium oxysporum, Rhizoctonia solani and S. rolfsii thus proving the pathogenicity following Koch’s postulates respectively. A minimum of eight per cent inoculum was found to be optimum to cause the wilt disaese.
How to cite this article:
Rani N, Yashoda R Hegde and Nargund VB. Symptomatology, proving pathogenicity and standardization of inoculum density of Fusarium oxysporum causing wilt of fenugreek. Journal of Pharmacognosy and Phytochemistry. 2017; 6(6): 505-509.