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ThesisItem Open Access Investigations on endophytic bacteria for management of downy mildew caused by Sclerospora graminicola in pearl millet(CCSHAU, Hisar, 2019-12) Sangwan, Pooja; Kushal RajPearl millet is a valuable staple food in semi-arid regions of the world. Pearl millet is affected by many diseases among them, downy mildew incited by oomycetes pathogen Sclerospora graminicola (Sacc.) Schroet is the most widespread and destructive disease of pearl millet. Endophytes play an important role in metabolism and physiology of the host plants. They provide multifarious benefits such as growth promotion, suppression of pathogens and nitrogen fixation. In the present study, roots and stubbles were collected from sick plot area of Bajra Pathology after the harvest of the pearl millet crop during Kharif 2016 and 2017. A total of 30 pearl millet root bacterial endophytes (PMRBE1- PMRBE 30) were retrieved from crushed roots of pearl millet streaked on Nutrient agar plates. Ten endophytic bacterial isolates were retrieved from roots of kharif 2016 crop and other twenty isolates from roots of kharif 2017 crop. All endophytic bacterial isolates were assessed for biocontrol activities. Amongst 30 pearl millet root bacterial endophytes, sixteen isolates were positive for siderophore production, three isolates viz. PMRBE6, PMRBE25 and PMRBE28 were found positive for HCN production, 30% of the bacterial endophytes showed good growth on ACC supplemented plates and cellulolytic activity was found in bacterial endophyte PMRBE18. The isolates PMRBE1, PMRBE4, PMRBE5, PMRBE6, PMRBE7 PMRBE17, PMRBE18, PMRBE20, PMRBE23 and PMRBE24 which showed maximum germination, seedling vigour index I & II and germination speed of three pearl millet cultivars HHB226, HHB67 Imp and 7042 S under in vitro conditions were selected for seed treatment as well as for foliar spray under screen house and field conditions. Amongst various pearl millet root bacterial endophytes, maximum germination, minimum downy mildew incidence at 30 and 60 DAS, better growth and yield of pearl millet cultivars were found on treatment with isolate PMRBE6, PMRBE18 and PMRBE23. On the basis of biochemical characterization and partial 16S rRNA sequencing pearl millet root bacterial endophytic isolates PMRBE6, PMRBE18 and PMRBE23 were identified as Bacillus subtilis strain PD4 (Accession no. MN400209), Serratia sp. and Alcaligenes faecalis strain HX2016003 (Accession no. MN400208). Promising root endophytes may be used for IPM of downy mildew in pearl millet after field trials.ThesisItem Open Access Variability, epidemiology and management of Tilletia indica Mitra, the incitant of Karnal bunt of wheat(CCSHAU, Hisar, 2019-11) Mamta; Rajender SinghKarnal bunt disease of wheat continues to be a potential threat to production and trade of wheat. The present study was planned to study cultural, morphological, molecular and pathogenic variability in Tilletia indica, epidemiology and management of this disease. On the basis of cultural and morphological characteristic, the largest teliospore size was observed in Bhiwani isolate, whereas Kapurthala isolate was having the smallest size. Different Karnal bunt isolates colony colour were white, yellowish white, creamy, creamish yellow and creamish white whereas, culture colony growth pattern of isolates were erect, compact, clustering, crustose, appressed, spreading and leathery. Maximum teliospore germination, primary sporidia formation and secondary sporidia production was recorded at 18°C in Pantnagar isolate. Best teliospore germination occurred at pH 6.0 followed by pH 5.0 Maximum coefficient of infection was expressed in HD2967 followed by DPW 621-50. Pantnagar isolate exhibited maximum mean coefficient of infection followed by Bhatinda and the least was observed in Mahendergarh isolate. Pantnagar isolate was most virulent as well as had maximum sporulation. Karnal bunt resistant reaction in three differentials namely HD 29, HD 30 and Aldan were noted. In molecular variability twelve molecular markers were tested against 10 Karnal bunt isolates and characterized into 3 major groups. Karnal bunt incidence had significant correlation with maximum temperature, rainy day and total rainfall during earhead emerging stage Two hundred seventy nine genotypes showed less than 5 coefficient of infection against Karnal bunt thereby expressing resistant reaction and 221 genotypes were susceptible having more than 5 per cent coefficient of infection under artificial inoculation condition. Maximum disease control was obtained by propiconazole 25% EC (0.1%) application, followed by combination of propiconazole 25% EC (0.05%), neem seed kernel and Trichoderma harzianum.ThesisItem Open Access Studies on variability and management of Verticillium fungicola causing dry bubble disease in Agaricus bisporus(CCSHAU, 2018) Jagdeep Singh; Surjeet SinghVerticillium fungicola is a serious pathogen causing dry bubble disease in button mushroom (Agaricus bisporus). Present investigations were carried out on both host and pathogen by covering aspects of variability in pathogen, host-pathogen interaction and management of the disease. The isolates of V. fungicola were collected from different mushroom farms of Haryana state, coded as MHS (Hisar), BFT (Fatehabad), NJN (Jind), RHT (Rohtak), TPN (Panipat), BSN (Sonipat), FDB (Fridabad) and SKK (Kurukshetra) and pathogenicity was proved on A. bisporus. All isolates showed morphological, physiological and pathological variations. The isolates BSN, TPN, FDB, SKK and RHT are fall in the fast growing category having radial growth of 44.66, 43.86, 43.33, 42.16 and 41.50 mm, respectively and whitish colonies with dark yellow underside on PDA at pH 6.5 and 25±1ºC temperature after 12 days of incubation. Similarly, during screening of the isolates, only BSN, TPN, FDB, SKK and RHT showed disease symptoms on fruiting bodies of all the strains of A. bisporous included in the study and other mushroom spp. i.e. A. bitorquis, Pleurotus sajor-caju and P. florida, except A. bisporus strain U-3 and Calocybe indica where no disease appeared. During interaction between A. bisporus and the virulent isolate (BSN) of V. fungicola, both are easily distinguishable at interaction regions on the basis of hyphal width i.e. ranged from 4.0 to 6.5 μm and 1.5 to 4.5 μm, respectively. Pathogen grows inter- as well as intra-cellularly on host hyphae, thereby causing coiling and lysis of host mycelia. During enzymatic bioassay in dual culture, the mycopathogen showed production of different hydrolytic enzymes i.e. amylase, cellulase and chitinase but not lipase and pectinase by formation of clear zonation on substrate. In in vitro studies three bacterial isolates i.e. BI, BII and BIII were isolated from casing soil for their antagonism against V. fungicola. The maximum growth inhibition of V. fungicola was 78.64% with BII isolate followed by 63.94% and 61.10% in BI and BIII, respectively after 12 days of incubation. The efficacy of neem products i.e. neem seed kernel extract, neem oil and neem leaf extracts, at three concentrations (2.5, 5.0 and 7.5 μl/ml) were determined against V. fungicola. The radial growth inhibition recorded was 50.02% at 7.5 μl/ml in case of neem seed kernel extract, followed by 40.99% and 34.94% in neem leaf extract and neem oil, respectively. Salicylic acid and jasmonic acid with different concentrations (0.1, 0.2 and 0.4 mM) were used and growth inhibition was 44.96% recorded at concentration 0.4 mM with salicylic acid, followed by jasmonic acid (23.42%) when evaluated against V. fungicola. In In vivo both salicylic acid and jasmonic acid resulted in reduction of lesions size on A. bisporus to the extent of 69.69% and 39.93%, respectively at concentration of 0.4mM. Similarly, the number of lesions reduction was 81.96% (salicylic acid) and 54.64% (jasmonic acid) at same concentration. The integrated managements of dry bubble disease caused by V. fungicola during the cultivation of A. bisporus in cropping period of 2016 and 2017 showed that all the treatments individually as well in combinations affected all yield parameters at all stages of growth of A. bisporus. However, the integrated disease management reported when treatments combination (bacterial isolate BII, neem seed kernel extract and salicylic acid) were applied at both spawning and casing time resulted in maximizing yield (24.75%) and minimizing disease incidence (4.31%) in cropping duration of 37 days.ThesisItem Open Access Ecofriendly management of Rhizoctonia solani causing black scurf of potato(CCSHAU, 2018) Manoj Kumar; Anil KumarIn recent years, among different fungal diseases of potato, black scurf disease has emerged as a serious problem caused by Rhizoctonia solani in most of the potato growing areas of India with 2-70 per cent disease incidence leading to considerable yield losses up to 50 per cent. Due to difficulties in disease management and lack of stable genetic resistance in potato cultivars against R. solani, different ecofriendly management aspects including fungicides, bioagents, organic amendments and cultural practices as well as systemic acquired resistance (SAR) activators in vitro and in vivo conditions were undertaken for effective management of the disease in present investigation. The in vitro and in vivo management study involving fungicides, bioagents or organic amendments indicated that among fungicides, Monceren, MEMC were most effective, whereas, in bioagents Trichoderma harzianum produced better results followed by T. viride. Among the organic amendments, vermicompost was found most effective followed by neem cake against black scurf of potato. Besides chemicals and biological control, cultural practices have also been used to minimize the inoculums level from the soil and tubers. Black scurf incidence is significantly influenced by irrigation level and depth of planting. As the irrigation frequency and depth of planting were increased, disease incidence and severity of potato black scurf was also increased. The delayed date of planting also affects disease incidence and severity. It was observed that soil moisture content is directly proportional to increased irrigation frequency and depth of planting. Black scurf disease incidence and severity showed a linear and negative correlation with soil temperature, whereas, a linear and positive correlation with soil moisture. Biochemical analysis indicated roles of systemic acquired resistance (SAR) inducing chemicals viz., salicylic acid, jasmonic acid, β-aminobutyric acid, γ-aminobutyric acid and hydrogen peroxide against black scurf of potato caused by R. solani. SAR activators play an important role in biochemical composition viz., total phenol, peroxidase, polyphenol oxidase and phenylalanine ammonia lyase and enhanced defense mechanism in potato crop for black scurf. It was also inferred from the study that all the biochemical constituents initially increased up to peak concentration after that, it decreased. Tubers dipping of SAR activators were found more effective to control the disease by reducing disease incidence as compared to foliar spray.ThesisItem Open Access Variability and management of rhizoctonia solani kuhn, the incitant of sheath blight of rice(CCSHAU, 2018) Pankaj Kumar; Anil KumarPresent investigation entitled ―Variability and management of Rhizoctonia solani Kuhn, the incitant of sheath blight of rice‖ revealed that Rhizoctonia solani isolates showed a considerably variation in cultural and morphological characters and pathogenic behaviour. There was no correlation of geographic location and source of isolation of the pathogen of the fungal isolates with the cultural, morphological and pathogenic clustering. ITS species specific primers indicated the intraspecific variation within R. solani isolates. R. solani was most dominant species associated with sheath blight complex in Haryana. However, R. oryzae was also found associated to the extent of 1.5%. Out of 307 rice genotypes evaluated, only one rice genotype i.e. RMS-BL-6 showed consistent resistant reaction against sheath blight during both years, indicating that resistance against sheath blight is rarely found. Among botanicals aqueous extracts of garlic cloves and turmeric powder proved effective in reducing disease severity while among fungicides azoxystrobin 18.2% + difenoconazole 11.4% SC and thifluzamide 23.9% SC proved to be the best treatments. None of the fungicide persisted till the harvest of crop i.e. 44 days after their last spray application in rice grains, cropped soil, paddy straw and husk indicating that these fungicides are safe for human, animal and environmental point of view. Among the combination of botanicals and fungicides, application of azoxystrobin 18.2% + difenoconazole 11.4% SC (1 ml/l) followed by extract of garlic cloves or turmeric powder at 50 g/l proved most effective but found out inferior to azoxystrobin 18.2% + difenoconazole 11.4% SC and thifluzamide 23.9% SC. All the herbicides inhibited the mycelial growth, sclerotial formation and sclerotial germination in vitro. Under field conditions pretilachlor 50 EC and pendimethalin 30 EC reduced the sheath blight severity alongwith significant increase in grain yield of paddy.ThesisItem Open Access Studies on interaction between endoparasi tic nematodes and Rhizobium in' legumes and influence of fertilizers, phytotherapeutic substances and host on nematode development(College of Agriculture Chaudhary Charan Singh Haryana Agricultural University Hisar, 1984) Dalal, M. R; Bhatti, D. SThesisItem Open Access studies on mosaic disease of Pea (pisum sativum L.)(College of Agriculture Chaudhary Charan Singh Haryana Agricultural University Hisar, 1984) Yadav, Om Parkash; Parashar, R. DThesisItem Open Access Studies on Bacterial Blight of Guar (Cyamopsis Tetragonoloba (L.) Taub.) Caused by Xanthomonas Campestris Pv. Cyamopsidis (Patel, Dhande and Kulkarni) Dye(College of Agriculture Chaudhary Charan Singh Haryana Agricultural University Hisar, 1984) Gandhi, Sudershan Kuamr; Chand, J. NThesisItem Open Access Survival, Pathogenesis And Chemical Control Of Fusarium Solani In Different Soils.(College of Agriculture Chaudhary Charan Singh Haryana Agricultural University Hisar, 1984) Monga, Dilip; Grover, R. K
