Browsing by Author "KOTASTHANE, ANIL S."
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ThesisItem Open Access DEFENCE MECHANISM IN RICE AGAINST SHEATH BLIGHT CAUSED BY Rhizoctonia solani Kühn(Indira Gandhi Krishi Vishwavidyalaya, Raipur, 2018) ROY, PULI SASANKA; KOTASTHANE, ANIL S.; PRAKASAM, V.; VERULKAR, SATISH BALKRISHNA; KHARE, N.; CHANDRAKAR, G.The present investigation entitled “Defence mechanism in rice against sheath blight caused by Rhizoctonia solani Kühn” were conducted in the laboratory and fields of Department of Plant Pathology, ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad, 500030. Rice is a most important cereal and is principle food for about 60% of the world’s population. The production and productivity of rice is reduced by numerous diseases caused by fungi, bacteria, virus, nematodes and other abiotic Title of the thesis “Defence mechanism in rice against sheath blight caused by Rhizoctonia solani Kühn” Full name of the student Puli Sasanka Roy Major subject Plant Pathology Name and Address of Major Advisor Dr. Anil. S. Kothesthane, Head and Professor, Dept. of Plant Pathology, CoA, IGKV, Raipur. Degree to be Awarded M. Sc (Ag) in Plant Pathology Signature of Student Signature of Major Advisor Date: _______________ Signature of Head of the Department xiv constraints. Rice sheath blight caused by Rhizoctonia solani Kuhn [telomorph: Thanetophorous cucumeris (Frank) Donk] is one of the major biotic constraint damaging rice production in India. In the present study, the differential behaviour of R. solani within the different tolerant and susceptible rice plants during different stages of infection. The R. solani hyphal behaviour within the host tissue was distinctly different in the susceptible and tolerant cultivars of rice. The growth of hyphae, formation of infection cushions, density of hyphae on leaf surface and formation of microsclerotia were high on susceptible cultivar when compared with the tolerant one. The correlation between trichomes and susceptibility of the plant was studied. The numbers of trichomes are more (30.76%) on the tolerant cultivar (Whazhuophek) when compared to susceptible cultivar (IR-50). The defence responses of tolerant and susceptible rice were monitored using biochemical analyses and expression analyses of selected defence related genes over a time course during different infection stages. Defence systems were differentially activated in tolerant and susceptible rice plants after inoculation with R. solani and it accounted for the difference in disease severity (PDI) in the those varieties. The pathogen R. solani induced Phenylalanine ammonia lyase (PAL), Superoxide dismutase (SOD), Peroxidase (POX), Polyphenol oxidase (PPO) in tolerant cultivars (Whazhuophek, Ngonolosa and Tetep) whereas in susceptible cultivars (TN-1 and IR-50), it had suppressed POX and SOD enzymes. Distinct difference was observed in activity of these enzymes in different cultivars at different times of course. The enzyme activity was observed peaks at 24 and 48 hours post inoculation mostly in all cultivars. The expression rate of selected defence related genes in two cultivars i.e., Whazhuophek as tolerant and IR-50 as susceptible were studied. The expression transcripts of defence related genes viz., PR-1, PR-2, PR-3, PR-4, PR-5, PR-9, PR-10, PR-13, CHS, LOX, PAL and PPO were studied by using quantitative Real-time PCR (qRT PCR). Results showed that the expression of all genes in tolerant cultivar were higher than that of susceptible cultivar, post inoculation. Significant differences were observed between these two cultivars. These studies suggest that the roles of these defese mechanisms are more significantly related to host-pathogen interaction.ThesisItem Open Access IDENTIFICATION OF POTENTIAL FLUORESCENT PSEUDOMONAS ISOLATES INDUCING DROUGHT TOLERANCE IN RICE AND WHEAT(Indira Gandhi Krishi Vishwavidyalaya, Raipur, 2018) AKASH, P.; VERULKAR, SATISH B.; JHA, ZENU; KOTASTHANE, ANIL S.; SAXENA, R.R.The present investigation was carried out in Microbial Biotechnology Laboratory at the Department of Plant Molecular Biology Laboratory, College of Agriculture, Indira Gandhi Agricultural University, Raipur, Chhattisgarh. Roots are the important part of a plant which were unnoticed in the circle of crop production of cereals. Roots which grow into the complex soil system have to face a lot of obstacles, both abiotic and biotic.The role of microbes in management of biotic and abiotic stresses is gaining importance and they are one of the major parts of soil which shows tremendous different activities in relation with crops. Beneficial microorganisms colonize the rhizosphere / endo-rhizosphere of plants and promote growth of the plants through various direct and indirect mechanisms. The development of stress tolerant crop varieties through genetic engineering and plant breeding is essential but a long drawn process, whereas microbial inoculation to alleviate stresses in plants could be a more cost effective environmental friendly option which could be available in a shorter time frame. Finding the effective isolate which can induce water stress tolerance in host plants requires both laboratory and on field studies. In the present study 31 fluorescent pseudomonas isolates(P1, P2, P3, P4, P5, P6, P7, P8, P10, P11, P12, P13, P14, P16, P17, P18, P19, P21, P22, P23, P24, P25, P27, P28, P29, P30, P66, P141, P200, P229, P260) were tested under different aspects like responds to different biochemical tests, PCR based molecular analysis and actual field performance. PCR based DNA finger printing revealed polymorphism between 31 isolates of fluorescent pseudomonas. All cultures responds variably towards biochemical tests and P5, P7, P8 and P10 were identified as the most potential isolate which can induce water stress tolerance to rice and wheat. These potential isolates can be further used for gene expression studies in host crops and can explore different array of changes.