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20205
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Subject: Plant Pathology × End date: 2020 × Start date: 2020 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Identification of noval donors for resistance against Tilletia indica causing Karnal bunt from wild and related species of wheat
    (Punjab Agricultural University, Ludhiana, 2020) George, Anju Grace; Vineet Kumar
    Karnal bunt (KB) of wheat caused by the fungus Tilletia indica is an internationally quarantine-significant disease of wheat. KB can be managed in a better way by exploiting genetic resistance in wild and related species of wheat. A population of 490 lines derived from progenitor species of wheat such as Aegilops tauschii and Triticum spp. (T. monococcum, T. boeoticum, T. dicoccoides), non-progenitor species Triticum araraticum and Aegilops triuncialis and triticale introgressions with wheat was utilized in this study. This study was conducted at the Experimental farm and laboratories, Department of Plant Breeding & Genetics, PAU Ludhiana during rabi seasons of 2018-19 and 2019-20. Among the progenitor and non-progenitor species and their bread wheat introgressions, Triticum araraticum 4747 /WHD 943 // bread wheat showed the highest level of KB resistance. This was followed by PDW 233 / Aegilops tauschii 14119// bread wheat. Among the triticale lines with diverse genetic background and their introgressions with bread wheat, TL 2908/2*CS(S)// DBW17 showed the highest level of KB resistance followed by T 3021/2* CS (S) // PBW 550. These lines were considered as promising donors for KB resistance and can be utilized for further breeding disease resistant varieties. Expressed Sequence Tag (EST) based markers specific for chromosome arms of rye were used to determine rye chromosomes associated with the KB resistant triticale x bread wheat lines. The introgressed regions of rye chromosome 4RL, 4RS and 7RL might have contributed to KB resistance in the phenotypically resistant lines.
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    ThesisItemRestricted
    Bio-management of chickpea wilt incited by Fusarium oxysporum f.sp. ciceri (Padwick) Synd. & Hans.
    (Punjab Agricultural University, Ludhiana, 2020) Arpanpreet Singh; Narinder Singh
    Fusarium wilt of chickpea caused by Fusarium oxysporum f.sp. ciceri is a serious disease in chickpea growing areas of Punjab. Rhizosphere soil samples were collected from chickpea fields of Ludhiana, Gurdaspur, Mansa, Moga and Bathinda regions and analysed for antagonistic microflora. Five isolates of Trichoderma spp. and three isolates of Pseudomonas spp. were isolated and screened in vitro for antagonistic activity against Fusarium oxysporum f.sp. ciceri causing wilt of chickpea. Th5 isolate of Trichoderma viride and Pf2 isolate of Pseudomonas aeruginosa showing maximum inhibition of 73.11 and 67.63 per cent against Fusarium oxysporum f.sp. ciceri in dual culture assay were selected. Th5 isolate also showed highest chitinase activity 8.85 unit/ml and Pf2 showed highest siderophore activity with the production of 29.07 mm diameter of orange to yellow coloured halo. Efficacy of talc based bioformulations of Trichoderma viride and Pseudomonas aeruginosa isolates applied as seed, soil and seed + soil treatment was seen against Fusarium wilt of chickpea under field and pothouse conditions. Maximum disease inhibition was observed in chemical treatment (Carbendazim) with 88.95, 88.12 and 88.72 per cent in Ludhiana, Gurdaspur and Pothouse trial, respectively, followed by the Trichoderma viride (Th5) seed + soil treatment with 81.84, 85.69 and 83.63 per cent disease inhibition in Ludhiana, Gurdaspur and Pothouse trial, respectively. Maximum growth promotion was also recorded in chemical treatment (Carbendazim) i.e. shoot length, root length and ultimately increased the yield of chickpea under both field and pothouse conditions followed by the isolate Trichoderma viride (Th5) seed + soil treatment. The rhizospheric competence of the antagonists showed that enough population density of antagonists was present throughout the crop period to control the pathogen both under both field and pothouse conditions. Maximum shelf life of talc-based powder bioformulation of all the antagonists was recorded in low temperature conditions (0°C) when packaged in polythene bags.
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    ThesisItemOpen Access
    Characterization of Tilletia barclayana causing kernel smut of rice and its management
    (Punjab Agricultural University, Ludhiana, 2020) Babanpreet Singh; Anju Bala
    Kernel smut of rice caused by Tilletia barclayana is a designated seed borne disease under Indian minimum seed certification standards. The pathogen converts the grains into black powdery mass resulting considerable loses in the yield as well as quality of the produce. The short duration rice varieties are more susceptible to kernel smut as compared to the other varieties. The present studies aimed at characterization of the populations of T. barclayana isolates obtained from different varieties under cultivation in Punjab from different agro-climatic regions and to devise management of this disease. A total of thirty three isolates of T. barclayana were obtained from thirteen districts and eight different varieties for morphological and pathological characterization. Based on the morphological and cultural characteristics, the isolates were grouped into 8 clusters, from each cluster representative isolates were selected for their pathological characterization under field conditions. Fourteen isolates were used for pathological characterization using spray inoculation technique at fifty per cent flower opening and by syringe inoculation technique at late boot stage. Multivariate cluster analysis of the pathogenicity data grouped the isolates into five and three clusters by spray and syringe inoculation method respectively. Isolate Tb 24 obtained from variety PR 124 from district Ropar was the most virulent isolate of T. barclayana whereas isolate Tb 31 obtained from variety PR 121 from district Tarantaran was the least virulent among the isolates under study. The germinated teliospores obtained from weed hosts, Dichanthium annulatum, Cyanodon dectylon were inoculated on variety PR 114 by spray inoculation method to study the cross infectivity of T. barclayana from weeds to rice. Neither of the isolate from any weed hosts were able to produce disease symptoms on rice. Six different fungicides including Hexaconazole 75% WG, Propicinazole 13.9% + Difenconazole 13.9% EC, Hexaconazole 4% + Zineb 68%, Tebuconazole 50% + Trifloxystrobin 25% WG, Azoxystrobin 23% SC, Propiconazole 25% were evaluated against T. barclayana under lab conditions and for disease control under the field conditions. Minimum ED 50 (3.57 ppm) and ED 90 (37.11 ppm) values were recorded for Hexaconazole 75% WG. Maximum disease control under field conditions was achieved in plots where two sprays of combination fungicide Hexaconazole 4% + Zineb 68% was given. The results of two sprays of Propiconazole 25% EC and combination of Tebuconazole 50% + Trifloxystrobin 25% WG @ 0.1 % and 0.04% respectively were equally effective for the management of disease under field conditions Fifty advanced breeding lines of rice were screened for disease reaction under natural conditions. Disease incidence and coefficient of infection was categorized into different response of disease reaction on the fifty advanced breeding lines under study at Ludhiana and Kapurthala. At PAU Ludhiana fourty six lines exhibited resistance response and four lines exhibited highly resistance response. At RRS Kapurthala 41 lines exhibited resistance response, one of the line was susceptible and seven lines were moderately susceptible to kernel smut under natural conditions. The lines showing resistance response can further be evaluated under artificial inoculation conditions in order to obtain resistance sources against the pathogen. The most virulent pathogen isolate Tb-24 may be used for artificial screening of lines against T. barclayana.
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    ThesisItemOpen Access
    Components of partial resistance against Neck Blast (Pyricularia Oryzae) in basmati rice
    (Punjab Agricultural University, Ludhiana, 2020) Sohal, Manarshroop Kaur
    The neck blast disease caused by Pyricularia oryzae was highly prevalent throughout the Punjab state with disease incidence ranging from 5.6 to 52.4 per cent on various basmati varieties. Highest disease incidence was observed in Mahal Kalan village of Barnala district. Amongst varieties, Pusa Basmati 1121 had highest value of disease incidence followed by Pusa Basmati 1401, Pusa Basmati 1509 and CSR 30. Significant variability amongst the neck blast isolates of the pathogen was observed with respect to various morphological and cultural characters viz., colony colour, colony texture, colony margin, mean radial growth (mm), spore size and sporulation intensity. The average sporulation intensity of the isolates on Oatmeal agar medium was 7.55×106 conidia /ml which was higher than the average sporulation intensity of isolates on Paspalum grass medium i.e. 6.97×106 conidia /ml. Three isolates namely NB 55, NB 57 and NB 60 were categorized as fast growing isolates with radial growth of >8mm per day. Various architectural features viz., flag leaf angle, flag leaf length, flag leaf width, panicle axis, panicle diameter, degree of exertion of panicle, culm length, 50% flowering and node aging were recorded in order to find correlation with various disease parameters viz., lesion length, panicle blast severity, area under disease progress curve (AUDPC), incubation period, disease incidence (%) and apparent rate of infection (R). Overall, flag leaf angle, panicle axis and node ageing emerged out to be three important components of partial resistance. Forty five basmati rice genotypes were screened under both artificial and natural conditions against the disease. Four genotypes i.e. Tetep, INGR 15001, INGR 15002 and Pusa Basmati 1637 were found to be moderately resistant to most virulent isolate NB 7 with susceptibility index was below 3 and they could be used as donors in breeding for disease resistance.
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    ThesisItemRestricted
    Characterization of Uromyces viciae-fabae (PERS.) J. SCHRÖT causing lentil rust and molecular tagging for its resistance
    (Punjab Agricultural University, Ludhiana, 2020) Jatinder Singh; Sirari, Asmita
    The population structure of rust isolates infecting lentil and pea in different districts of Punjab was revisited on the basis of cross infectivity test and molecular characterization. Both lentil and pea rust isolates were found non-cross infective at different stages of plant growth. The ITS region of ~700 bp, amplified from DNA of these isolates showed 97 to 99.24% sequence homology with Uromyces viciae-fabae with more than 90% query cover. The sequences were then submitted and accession numbers were provided by GenBank. Further, analysis showed less genetic variation among these isolates. Genetically diverse microsperma and macrosperma lentil lines could not differentiate the rust populations prevalent at Gurdaspur and Ludhiana. Further, recombinant inbred lines (RILs) developed from cross between rust resistant (FLIP-2004-7L) and susceptible (L-9-12) cultivars were phenotyped against lentil rust for genetic analysis and molecular mapping. Genetic analysis indicated the role of major gene in resistance. The phenotypic data was also used to identify molecular markers associated with rust resistance. Out of 389 SSR markers, available in public domain, two markers, namely, LcSSR 440 and LcSSR 606 were found to be linked with rust resistance at 8.3 and 8.1cM, respectively. Availability of high-density linkage maps and genome sequence information in lentil can be helpful to extend the present study in identifying candidate resistance genes against U. viciae-fabae