RAGHUWANSHI, K. S.Thakur, Vishal Jagannath2017-12-042017-12-042011http://krishikosh.egranth.ac.in/handle/1/5810036794Pomegranate (Punica granatum L.) a hardy evergreen to deciduous shrub tending to be a tree is an ecologically adopted species to dry climate. It belongs to family Punicaceae, which is known as Anar in Hindi and Dalimb in Marathi. The ancient world fruit originated in Persia, Iran, Afghanistan and Baluchistan (DeCandolle, 1967). The present investigations were carried out on wilt of pomegranate caused by Fusarium oxysporum in respect of occurrence, symptomatology, isolation of pathogens, pathogenicity, identification of pathogen, morphological studies and molecular diversity in vitro. Wilted pomegranate plants were collected from Sangamner Tahsil of Ahmednagar District, Devala, Malegaon and Satana Tahsils of Nashik District. Baramati tahsil of Pune District, Jat tahsil of Sangli District and Pandarpur tahsil of Solapur District. The sample were collected from the orchard grown under drip irrigation method. The plants showing partial wilting, typical yellowing and wilting symptoms were digged out and the root samples were brought to laboratory for further studies. The symptoms of the disease were characterized as change in colour of young leaves from dark green to light green and finally become yellow. In advance stage, leaves dry and finally entire plant wilt and died. The isolation of the fungus was carried out from the infected root and bark of collar region of wilted plants. The pathogenicity of the isolated fungus was proved by culture filtrate method. The morphological characters of the pathogens were studied. The fungal pathogen i.e. Fusarium oxysporum produced cottony white mycelium which was branched, septate and hyaline. The macro-conidia were fusiform, curved or falcate and septate while the micro-conidia were usually oval, hyaline and mostly a septate. The mycelium was septate hyaline, profusely branched measured 1.15-4.15 µm in width. Chlamydospores produced in all the isolates were vary in their diameter which ranged from 4.56 to 9.82 µm. The length and breadth of macrocondia were in the range of 8.92-28.26 µm and 0.92-3.72 µm respectively while length and breadth of microconidia were in the range of 2.94-5.84 µm and 0.69-2.31 µm, respectively. In the pathgoenicity test of the isolates of Fusarium oxysporum was determined by culture filtrate method in-vitro. Times taken for wilting of plants were different with different isolates. For determination of molecular variability in Fusarium oxysporum total number of 16 fungal primers were used out of these 16 primers were polymorphic primers. There were total 204 number of band generated out of which 114 bands were polymorphic bands and 88 bands were unique bands showing 55.88 per cent polymorphism in general. Out of 16 primers used primers Rfa-2, Rfa-5, Rfa-10, Rfa-13, Rfa-14 and Rfa-16 were best for variability study as they generated more polymorphic bands. Rfa-5, Rfa-10, Rfa-13, Rfa-14 and Rfa-11 showed 81.81, 69.23, 69.23, 72.72, 85.71 and 66.66 per cent polymorphism respectively. According to tree dendrogram and 2-D scatter plot analysis the Sangmner and Baramati isolates are closely related to each other than the isolate of Jat, while the Malegaon, Deola and Satana isolates were closely related to each other than Pandharpur isolate. Finally, according to all 2D-scatter and tree dendrogram analysis it was clear that Sangamner, Baramati and Jat isolates was distinct from remaining four isolates viz., Pandharpur, Malegaon, Deola and Satana isolates.ennullThesis