No abstract

Fusarium oxysporum which causes wilt is a serious pathogen. Fusarium isolates were isolated from Assam located in North East region of India. Morphological identification of Fusarium isolates was done using conidial and hyphal structures. Molecular identification of Fusarium isolates was done by amplifying the internal transcribed spacer (ITS) region of the conserved ribosomal DNA using primers ITS1 and ITS4. All the ITS sequences were compared for gaps and similarity. Further, characterization of random amplified polymorphic DNA (RAPD) was carried out using 40 primers. 15 primers that gave reproducible results were selected. RAPD was used to observe the relatedness among these isolates. Thus, it was concluded that molecular profiling using ITS is an indispensable method for identification studies.

The main objective of this study was to evaluate the effectiveness of crude chloroform extract of Piper betle L. (PbC) in controlling Fusarium wilt of tomato (Lycopersicon esculentum) caused by Fusarium oxysporum f. sp. lycopersici. It was observed that 1% (w/w) amendment of the PbC in soil was more efficient in reducing the Fusarium population in soil than carbendazim and the combined amendment of carbendazim and PbC. Fusarium wilt control studies were carried out in a greenhouse. Variation in different parameters like shoot growth, root growth and mean fresh weights of tomato seedlings in all the treatments were recorded. Accumulation of total phenolics was also studied from the root tissues of tomato. Higher accumulation of total phenolics was observed in the Fusarium-infested plants as compared to that of healthy control and PbC-treated plants. Moreover, it was observed that the extract could reduce the symptoms and disease development. Electron microscopy studies were also done to observe the Fusarium infestation in the vascular bundles and to show the accumulation of total phenolics in the vacuoles of root tissue.

No abstract