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Dr. Rajendra Prasad Central Agricultural University, Pusa

In the imperial Gazetteer of India 1878, Pusa was recorded as a government estate of about 1350 acres in Darbhanba. It was acquired by East India Company for running a stud farm to supply better breed of horses mainly for the army. Frequent incidence of glanders disease (swelling of glands), mostly affecting the valuable imported bloodstock made the civil veterinary department to shift the entire stock out of Pusa. A British tobacco concern Beg Sutherland & co. got the estate on lease but it also left in 1897 abandoning the government estate of Pusa. Lord Mayo, The Viceroy and Governor General, had been repeatedly trying to get through his proposal for setting up a directorate general of Agriculture that would take care of the soil and its productivity, formulate newer techniques of cultivation, improve the quality of seeds and livestock and also arrange for imparting agricultural education. The government of India had invited a British expert. Dr. J. A. Voelcker who had submitted as report on the development of Indian agriculture. As a follow-up action, three experts in different fields were appointed for the first time during 1885 to 1895 namely, agricultural chemist (Dr. J. W. Leafer), cryptogamic botanist (Dr. R. A. Butler) and entomologist (Dr. H. Maxwell Lefroy) with headquarters at Dehradun (U.P.) in the forest Research Institute complex. Surprisingly, until now Pusa, which was destined to become the centre of agricultural revolution in the country, was lying as before an abandoned government estate. In 1898. Lord Curzon took over as the viceroy. A widely traveled person and an administrator, he salvaged out the earlier proposal and got London’s approval for the appointment of the inspector General of Agriculture to which the first incumbent Mr. J. Mollison (Dy. Director of Agriculture, Bombay) joined in 1901 with headquarters at Nagpur The then government of Bengal had mooted in 1902 a proposal to the centre for setting up a model cattle farm for improving the dilapidated condition of the livestock at Pusa estate where plenty of land, water and feed would be available, and with Mr. Mollison’s support this was accepted in principle. Around Pusa, there were many British planters and also an indigo research centre Dalsing Sarai (near Pusa). Mr. Mollison’s visits to this mini British kingdom and his strong recommendations. In favour of Pusa as the most ideal place for the Bengal government project obviously caught the attention for the viceroy.

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2015 - 201718
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Subject: Agricultural Biotechnology × End date: 2017 × Start date: 2015 ×
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    ThesisItemOpen Access
    Biotechnological development of Panama wilt resistance in local cultivars of banana
    (RAJENDRA AGRICULTURAL UNIVERSITY, BIHAR PUSA (SAMASTIPUR), 2017) Kumari, Anita; Kumar, Harsh
    Biotechnological development of resistance to Panama wilt, the most important disease caused by Fusarium oxysporum f.sp. cubense, was explored in four important local cultivars of banana namely Robusta, Alpan, Malbhog and Kothia employing tissue culture studies and genetic transformation. Using tissue culture, efficient micropropagation protocol and disease resistance utilizing somaclonal variation were developed. Biological control and management of the disease was done utilizing endophytic association of nonpathogenic strain of Fusarium oxysporum. The culture of shoot apices and male flower buds resulted in their establishment and swelling, and callogenesis, caulogenesis, differentiation of shoots and roots from them. Elongation of existing shoots was observed from shoot apices and somatic embryogenesis from floral buds only. The best medium for caulogenesis was BM19 (MS+1.14 µM IAA+19.97 µM BAP) for cultured shoot apices and medium BM8 (MS+22.19 µM BAP) for cultured male flower buds. The best medium for somatic embryogenesis was BM20 (MS+18.10 µM 2,4-D+5.37 µM NAA+ 5.71 µM IAA+ 1mg Biotin). The cultivar Robusta was the best for all tissue culture responses except somatic embryogenesis followed by either cultivar Alpan or cultivar Malbhog. The cultivar Kothia showed the least tissue culture responses. However, the best response for somatic embryogenesis was observed in cultivar Kothia followed by cultivars Malbhog, Alpan and Robusta respectively. The subculture of in vitro developed multiple shoots on medium BM19 resulted in cent percent shoot multiplication with a high multiplication rate. An efficient micropropagation protocol was developed for banana cultivars. The Panama wilt resistance was developed in two susceptible cultivars Alpan and Malbhog exploiting somaclonal variation. Endophytic nonpathogenic Fusarium oxysporum strains were found effective in biocontrol of wilt disease in banana. Genetic transformation of callus and regenerating shoots was done using GUS and eGFP marker gene constructs and it was confirmed using histochemical GUS assay and fluorescence microscopy respectively, and by molecular validation using specific SSR primer pairs. Thus, the work established a suitable protocol of the genetic transformation, which can be used for the development of Panama wilt resistance in local cultivars of bananas.
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    ThesisItemOpen Access
    Microsatellite markers based assessment of genetic diversity and construction of heterotic groups in maize
    (Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), 2016) Punya; Sharma, V. K.
    A study was undertaken to elucidate the nature and extent of differentiation and divergence among eighteen inbred lines of maize and to separate them into heterotic groups based on the analysis of targeted microsatellite sites. Experimental materials of the present study comprised fifteen inbred lines, three testers and forty five single cross experimental hybrids, which were evaluated in randomized block design with three replications under rabi and kharif seasons. Statistical analyses to derive inferences regarding divergence pattern of parental lines and heterosis manifestation in experimental hybrids were carried out using the data recorded on days to tasseling, days to silking, days to brown husk, plant height, ear height, ear length, number of kernels per ear and grain yield per plant. Numerical taxonomic approach of classification using these eight quantitative characters of agronomic importance based average taxonomic distance was done to discriminate the inbred lines into different clusters. Inbred lines were also raised in pots for extraction of genomic DNA from the young seedlings. Amplification of the genomic DNA was carried out using a panel of twenty eight microsatellite sites specific primer pairs covering all the chromosomes existing in the genome. Microsatellites based allelic diversity data were utilized for classification and formation of heterotic groups of the inbred lines. Analysis of variance revealed the existence of significant differences among the inbred lines and hybrids for all the characters recorded under both the seasons. Mean performance of parents and hybrids significantly varied for the eight quantitative characters under study. Among the inbred lines, CML467 recorded significantly higher grain yield per plant followed by tester CML165, which was statistically at par to inbred lines LM13, HKI586, CML465, HKI162 and HKI323B over the environments. Sixteen crosses recorded significantly higher mean performance and significantly positive heterosis for grain yield per plant. Among these sixteen crosses, the highest yielding cross HKI162 × CML161 was statistically at par to five crosses, namely, CML468 × CML161, CML471 ×CML161, HKI323B × CML161, CML469 × CML165 and CML471 × CML165 for grain yield per plant. Taxonomic distance based cluster analysis revealed ample genetic diversity among inbred lines, which occupied different clusters during rabi and kharif season and across the seasons. The results indicated a close correspondence with respect to clustering pattern of inbred lines during rabi and kharif seasons. A perusal of dendrogram generated on the basis of eight quantitative traits indicated that the inbred lines CML467, CML470 and DH2012 were relatively more diverse from the remaining inbred lines under evaluation. Altogether 296 allelic variants were detected amongst amplified products generated with 28 primer pairs. A total of 49 loci were assigned to 28 primer pairs with an average of 6.04 alleles per locus The number of alleles ranged from 6 in the cases of umc1136, phi072 and umc1179 to 16 in case of phi053 with a range between 56 to 352 bp. Considering the number of alleles generated by different primer pairs in conjunction with the level of polymorphism, the primers umc1297, phi053, umc1266, phi093, bnlg118, phi034, phi115, phi065 and phi084 appeared to be more informative primers. Among the inbred lines under molecular characterization, CML163 and CML467 appeared as the most diverse genotypes. A remarkably higher level of genetic polymorphism was revealed by the use of 28 microsatellite markers. Both quantitative and molecular data based cluster analyses revealed that inbred lines CML 468 and CML469 are closely related to each other. Remarkably greater extent of similarity was also noticed between inbred lines HKI323B and HKI586. All the three testers, namely, CML161, CML165 and CML163, were included in same cluster in both the cases and seemed to be closely related. However cluster analysis using quantitative characters and microsatellite markers based data did not exhibit a complete correspondence. Parental genetic distance based on quantitative data or genetic similarity based on molecular data did not exhibit significant association with grain yield heterosis in hybrids. Results clearly indicated that a high grain yield is not always obtained from hybrids that have high parental genetic distance value, but generally from those with moderate to high genetic distance. A comparative assessment of heterotic groups formed by using microsatellite markers based genetic similarity, hybrid index value and hybrid mean value, indicated that CML471 and CML115 or HKI323B and HKI586 or DH2012 and LM13 belonged to same heterotic group in all the cases. The distribution pattern of the entries into different heterotic groups formed on the basis of hybrid index value and hybrid mean value corresponded with the microsatellite markers based heterotic groups to the extent of 75% and 67% in the first heterotic group, 40% and 29% in the second heterotic group and 33% and 40% in the third heterotic group, respectively. Overall coincidences of inbred lines in heterotic groups formed on the basis of microsatellite markers with the hybrid index value and hybrid mean value based heterotic groups were considerably higher. Results, therefore, indicated that microsatellite markers may be effectively and efficiently utilized to assign the inbred lines to heterotic groups for grain yield and to establish heterotic groups of maize inbred lines.
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    ThesisItemOpen Access
    Gene Expression Analysis For Biosynthesis And Catabolism Of Glucosinolates In Rocket (Diplotaxis tenufolia L.) Under Abiotic Stress
    (Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), 2017) Mishra, Shubhi; Kumar, M.
    Glucosinolates are one of the important nutritive content of rocket (Diplotaxis tenufolia L.), a leafy vegetable salad crop. They are responsible for its pepper taste, pungent aroma and medicinal properties. In this experiment, content of chlorophyll and chlorophyll fluorescence parameters were measured and biochemical analysis of glucose and glucosinolates content was done. The experiment was further followed by expression profiling of the key genes of metabolic pathway of glucosinolate using real-time PCR. The results indicated that the plant had some adaptation mechanism to mitigate the adverse effects of heat and salt stress which resist the changes in the chlorophyll content and chlorophyll fluorescence of rocket leaves as non-significant changes in the chlorophyll content and chlorophyll a fluorescence of rocket leaves.An increase in glucosinolate content was observed due to heat and salt stress in agreement with the inference derived on the basis of gene expression analysis. However in the case of roots, it appeared that glucosinolates content started decreasing after reaching the saturation point which was amply supported by higher level of expression of glucosinolates catabolism gene DtMyrosinase as observed in roots.It appeared that glucosinolates content can be increased if grown under heat and salt stress and can also be limited if grown under controlled condition. Isolation of the full length of key genes involved in glucosinolates biosynthesis namely, DtCytochromeP79F1 and catabolism namely, (DtThiol-methyl transferase) was also done through RACE. Altogether ten primers including eight primers specific to target the eight genes of glucosinolate metabolic pathway and two RACE specific primers were designed and validated during the present study which may be further utilized as tools to examine target region amplification polymorphism and expression in relation to glucosinolate biosynthesis pathway in rocket plants.
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    ThesisItemOpen Access
    Genome wide association study for identification of genes related to ion accumulation in rice grain
    (Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), 2017) Kumar, Ajay; Sharma, V. K.
    A study was conducted to investigate and identify the candidate genes in relation to cadmium and zinc transportation and accumulation in rice. Using 281 diverse rice accessions and employing genome wide association analysis to relate 46294 single nucleotide polymorphic panel and cadmium and zinc ionomic data, mixed linear model was adopted to establish the association, if any, between genotypic and ionomic data. Statistical tools used and computational applications adopted during the analyses include Discriminant Analysis of Principal Components (DAPC), Principal Coordinate Analysis (PCoA), Neighbour Joining Tree, Structure, Haploview and R-tool. Differential accumulation of cadmium and zinc in different vegetative tissues of two diverse rice accessions was also investigated under cadmium induced stress condition. Finally, expression profiles of OsHMA2, OsHMA3 and OsPCSs genes under cadmium induced stress condition were examined. Differential cadmium accumulation was recorded in grains of rice accessions evaluated under alternate wetting and drying and permanent flooding conditions as well as across the conditions. While in the case of zinc, differential accumulation was observed between accessions but differences recorded between conditions were not so pronounced. PCoA based on SNPs data derived using 297 accessions clearly indicated that 12 entries were very diverse from rest of the entries under evaluation. Further, an analysis using neighbour joining tree based on distance matrix also revealed that these 12 genotypes were remarkably distant from rest of the entries. Cluster analysis applied to detect population genetic structure clearly indicated that 10 out of these 12 accessions belonged to a separate cluster. Finally, an analysis carried out after exclusion of 16 accessions including 12 accessions, which were found to be more diverse based on PCoA and neighbour joining tree and 4 very late maturing accessions, established that remaining 281 accessions belonged to three clusters. DAPC employed to find out the optimum number of clusters confirmed the results obtained through PCoA, neighbour joining tree and cluster analysis applied to detect population genetic structure in the present investigation. Association analysis revealed twelve and two markers; seven and one candidate loci; and 109 and 10 candidate genes associated with cadmium and zinc accumulation, respectively. Haplotype analysis of polymorphic markers identified in relation to cadmium and zinc accumulation, therefore, resulted in allocation of seven and one loci, respectively, in question to haplotype groups. Result of the present study led to the identification of candidate genes involved in cadmium and zinc accumulation under aerobic condition. Altogether, eight and five genes appeared to be involved in cadmium and zinc accumulation, respectively. Present study, therefore, provided the evidence based on which the candidate genes most likely to be involved in zinc accumulation have been proposed. Most probable involvement of MATE and PEZ family genes in cadmium accumulation in rice grain was confirmed on the basis of results of present study. Cadmium accumulation property appeared less dependent on its uptake by the plants but more dependent on the capacity of the accession to trap the cadmium into the roots by synthesizing two folds non-protein thiol content, thereby preventing its translocation or mobility from root to shoot. Antagonistic effect of cadmium accumulation was observed in respect of zinc accumulation in rice accessions. Expression analysis in relation to cadmium ion translocation reflected that OsHMA3 was more expressed in less efficient accession as compared to the efficient accession. Therefore, the overexpression of OsHMA3 most probably resulted in low accumulation of cadmium in the plants of less efficient accession due to lesser translocation.
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    ThesisItemOpen Access
    Microsatellite markers based characterization of rice genotypes in relation to drought tolerance
    (Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), 2017) Choudhary, Shuchi Shankar; Kumar, Mithilesh
    Eighteen genotypes of rice were evaluated for various physio-morphological characters and to investigate the microsatellite markers based polymorphism for their characterization and differentiation using polymorphic and informative markers in order to estimate the extent of genetic diversity among these rice genotypes.Experimental materials were evaluated in randomized block design with three replications during three consecutive years. Molecular characterization was done by targeted amplification of the genomic DNA using a panel of thirty two microsatellite primer pairs covering nine chromosomes. Statistical methods and parameters used for deriving inference were analysis of variance, range, mean values, relative mean performance, drought tolerance indices, variability parameters, correlation andpath coefficients. An analysis of variance revealed significant differences among the genotypes for all the characters evaluated during present study. Considerable extent of variability existed for all the attributes recorded among the genotypes. The coefficient of variability was recorded moderate to high genetic variability for number of grains per panicle, root length and yield per plant under normal condition consistently over years, whereas for leaf rolling, number of tillers per plant, number of grains per panicle, plant height, harvest index and yield per plant under drought condition. Yield per plant recorded high variability amongst the genotypes evaluated under both conditions.The genotypes RAU-1426-4-3-2-57-2, RAU-1416-4-2-5-2-2 and Sahbhagi Dhan recorded remarkably higher mean performance fornumber of tillers per plant, number of grains per panicle, 1000-grains weight, harvest index and yield per plant, under both drought and normal conditions. Similarly, genotypes like RAU-1397-2-5-8-1-2-5-4, RAU-1453-12, RAU-1451-6-6-1-1-5-2 and Sahbhagi Dhan exhibited superior performance in respect of root length, plant height, dry root weight, relative leaf water content, canopy temperature and number of grains per panicle under both drought and normal conditions. The relative mean performance of genotypes, namely,RAU-1421-12-1-7-4-3, RAU-1415-3-5-7-6-9-5-3, RAU-1401-1-8-1-5, RAU-1478-5-2-2-4-6, RAU-1451-6-6-1-1-5-2, RAU-1416-4-2-5-2-2, RAU-1426-4-3-2-5-7-2, RAU-1453-12 and Sahbhagi Dhan to be relatively more drought tolerant than other genotypes under evaluation. Root length, plant height, dry root weight, spikelet fertility, number of grains per panicle, 1000-grain weight, harvest index and yield per plant exhibited moderate to high heritability in broad sense coupled with moderate to high estimates for genetic advance as per cent of mean under both drought and normal conditions over years.Correlation studies, revealed that root length, number of tillers per plant, relative leaf water content, spikelet fertility, 1000-grain weight and harvest indexshowed significant positive association with yield per plant under both conditions. However, positively significant association was also observed between yield per plant and number of grains per panicle under drought condition.Path coefficient analysis revealed that the characters, namely, numbers of tillers per plant, root length, dry root weight1000-grain weight and harvest index had considerable positive direct effects on yield per plant more or less consistently across the years under drought as well as normal conditions.Four tolerance indices viz. TOL, SSI, DTE and STI were used. According to TOL, SSI and DTE, 12 genotypes,namely, RAU-1421-12-1-7-4-3, RAU-1415-3-5-7-6-9-5-3, RAU-1401-1-8-1-5, RAU-1478-5-2-2-4-6, RAU-1477-9-7-2-2-5-7-3, RAU-1451-6-6-1-1-5-2, RAU-1416-4-2-5-2-2, RAU-1426-4-3-2-5-7-2, RAU-1463-16, RAU-1471-10, RAU-1453-12 and Sahbhagi Dhan appeared to be relatively more tolerant to drought stress. Among these 12 genotypes, 7 genotypes namely,RAU-1421-12-1-7-4-3, RAU-1415-3-5-76-9-5-3, RAU-1451-6-6-1-1-5-7-3, RAU-1416-4-2-5-2-2, RAU-1426-4-3-2-5-7-2, RAU-1453-12 and Sahbhagi Dhan recorded higher STI valueexhibiting high tolerance to drought condition. Using a set of thirty two microsatellite primers generated allelic variants ranged from 4 in case of RM 85 to 16 in case of RM 324 and RM518.The primer pair RM 3,RM 18, RM 72, RM 87, RM225, RM 262, RM302, RM 324, RM 327, RM 416, RM 518, RM 520, RM 521, RM1349, RM 5443 and RM 23679generated amplified products due to amplification of more than one microsatellite locus. Altogether 300 allelic variants were detected at 48 microsatellite loci with an average of 6.25 alleles per locus. A total of 174 shared and 126 unique allelic variants were generated. Considering the number of alleles in conjunction with the level of polymorphism detected, the primersRM 231, RM 225, RM 163, RM 555, RM 212, RM 72, RM 3549, RM 1349, RM 521, RM 5443 and RM 302 appeared to be more informative primers.Analysis of divergence pattern based on microsatellite markers allowed differentiation and classification of rice genotypes into two groups. The first multi-genotypic group consisted of twelve genotypes, namely, RAU-1428-6-7-3-6, RAU-1417-2-1-5-7-7,RAU-1421-12-1-7-4-3, RAU-1415-3-5-76-9-5-3, RAU-1401-1-8-1-5, RAU-1428-4-3-2-7-26, RAU-1478-5-2-2-4-6, RAU-1477-9-7-2-2-5-7-3, RAU-1451-6-6-1-1-5-2, RAU-1416-4-2-5-2-2, RAU-1397-2-5-8-1-2-5-4 and RAU-1451-3-5-7-6-9-5-1 whereas the second multi-genotypic group consisted of six genotypes, namely, RAU-1426-4-3-2-5-7-2, RAU-1428-3-1-5-4, RAU-1463-16, RAU-1471-10, RAU-1453-12 and Sahbhagi Dhan.The maximum similarity value of 0.46 was observed between the genotypes i.e. genotype RAU-1477-9-7-22-5-7-3 and RAU-1451-6-6-1-1-5-2 indicating that these were more closely related. The panel of microsatellite markers employed for molecular characterization in the present study showed very high degree of efficiency in discrimination of genotypes in relation to drought tolerance.
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    ThesisItemOpen Access
    Characterization of wheat (Triticum aestivum L.) genotypes for disease reaction against spot blotch pathogen
    (Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), 2017) Kumari, Priti; Kumar, Rajeev
    Wheat (Triticum aestivum L.) is the largest consumed cereals and most important element in the diet of the poor. Successful production of the wheat in the warmer regions of South Asia is constrained by several biotic and abiotic stresses. Spot blotch of wheat caused by Bipolaris sorokiniana is one of the most significant biotic stresses which limits the production and productivity of the crop in the region. Under present investigation eighty-eight genotypes of wheat were evaluated for the purpose of twelve morpho-metric traits and reaction against spot blotch disease in randomized block design (RBD) during rabi, 2015 Molecular characterization using 17 SSR markers (associated with tolerance against spot blotch disease) was also undertaken to as certain the genetic diversity among the studied genotypes Observations on 1000-grain weight, grain filling duration (GFD), no. of tiller per plant, canopy temperature, yield per plot, heading, days to greenness, disease severity and area under disease progress curve (AUDPC), lesion size, leaf tip necrosis, biomass per square meter were recorded. Significant differences were observed among the genotypes for all the traits under consideration. Genotype × environment interactions were found non-significant. Molecular characterization work revealed a total of 232 alleles in 19 genotypes using 17 SSR markers. The number of alleles per locus varied from four in Xgwm371 to thirty in Xgwm 445 with an average of 11.04 alleles per locus. Total 165 unique alleles were observed at 21 SSR loci, with an average of 7.85 unique alleles per locus. The number of unique alleles per locus ranged from one in Xgwm 371 to twenty six in Xgwm 445. Out of 17 SSR primers 10 showed null alleles. The maximum 4 genotypes (Ariana, Dharwad Dry, Ciano T 79 and HD 2967) exhibited null alleles for the primer pair Xgwm 120. Stutter bands were also detected in the present investigation. Such bands were observed in the case primer pairs, Xgwm-611, Xgwm-159 Xgwm 132, Xgwm 445, Xgwm 371, Xgwm146, Xgwm 425. The PIC values varied from 0.435 in the case of Xgwm120 to 0.959 in the case of Xgwm 146 with an average of 0.876 across the primer, indicating that the markers were highly informative (PIC>0.5). The use of SSR markers in the present analysis exhibited a remarkably higher level of genetic polymorphism and allowed unique genotyping of the genotypes included in the analysis. The nineteen genotypes classified into five different clusters or groups (I to V) at 22 phenon level based on cluster analysis using the UPGMA method based on Dice coefficients.
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    ThesisItemOpen Access
    Molecular Characterization of Bipolaris sorokiniana Isolates Collected from Wheat by SSR Markers
    (Rajendra Agriculrural University, Pusa (Samastipur), 2016) Bharty, Archana; Kumar, Harsh
    Spot blotch of wheat caused by Bipolaris sorokiniana is one of the most important fungal diseases of wheat (Triticum aestivum). The pathogen is seed and soil borne. Pusa in Bihar is considered as a hot spot for the disease. 36 fungal isolates were collected from infected leaves and seeds of different wheat genotypes grown at the research farms of RAU, BISA, IARI Regional Station at Pusa and from Patna, Muzaffarpur, Nalanda, Madhepura, Mahua and Jamaui. They were characterized morphologically on the basis of colony colour, growth pattern and exudation, and molecularly through SSR markers. The isolates were tested on two wheat cultivars, susceptible Sonalika and resistant Chirya-3 for disease severity, AUDPC and aggressiveness under natural condition in field and controlled condition in polyhouse. The isolates were divided into five morphological groups on the basis of their colony colour namely black, grey, grey cottony knot, grey white and whitish black, among which the frequency of black was the maximum and showed high aggressiveness. To examine the molecular genotypic variability among the isolates, their genomic DNA was isolated and amplified using 10 Bipolaris specific SSR (microsatellite) primer pairs. A total of 110 allelic variants were detected including 35 unique alleles, 75 shared alleles (including 7 null alleles) at 18 loci with an average number of 6.11 alleles per locus during the amplification reaction conducted with the thirty six entries. The primer pairs BSO96 and BS065 appeared to be highly polymorphic and comparatively more informative primers for molecular characterization and differentiation of thirty six Bipolaris sorokiniana isolates. The dendrogram was generated following UPGMA and the clusters were identified at appropriate pennon level. There were nine clusters A to I at eighty five similarity units. Entries R.G.T-78 and R.G.T-79 were relatively more closely related with the highest similarity coefficient amongst the thirty six entries evaluated. Analysis of divergence pattern based on amplification profile allowed differentiation of thirty six isolates. The different clusters of isolates showed differentiation for aggressiveness. Bipolaris sorokiniana of cluster A were the highly aggressive and of clusters B, C, D, F and G were moderately aggressive. Those of clusters E, H and I were the least aggressive. Thus molecular marker can differentiate the Bipolaris sorokiniana fungal isolates in general and for their relative aggressiveness.
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    ThesisItemOpen Access
    Morpho-Molecular Characterization of Elite Germplasm of Sweet Potato (Ipomoea batatas L.).
    (Rajendra Agricultural University, Pusa (Samastipur), 2015) Singh, Chandra Prakash; Kumar, Harsh
    The present investigation was carried out to characterize 17 elite genotypes of sweet potato(Ipomoea batatasL.) using morphological features and molecular markers. Genotypes were evaluated for eleven traitsnamelynumber of branch, vine length, number of leaves/plant, leaf area, leaf area index, length of tuber, girth of tuber, neck length, average weight/tuber, yield/hectare and skin and flesh colour.The mean square due to genotypes was found significant for all the characters. The mean performance of genotypes has been compared with the check Shree Bhadra for each character as it is one of the commonly cultivated genotypes of Bihar.The observations were also recorded based on descriptors coding in the Descriptors of Sweet Potato (Human, 1991) for grouping of the seventeen genotypes of sweet potato under study on the basis of their similarity and differences with respect to vine length, neck length, flesh colour and skin colour. The exploitable extent of genetic variability amongst the entries was present as revealed by considerably higher estimates of GCV, PCV, h2 and GA as percentage of mean. For GCV the highest value was recorded for leaf area index (51.57) and the lowest for girth of tuber (20.56). For PCV the highest value was recorded for leaf area index (53.76) and the lowest for girth of tuber (21.79). For heritability the highest value was recorded for leaf area (97.19) and the lowest for length of tuber (78.50). For GA as percentage of mean the highest value was recorded for leaf area index (97.56) and the lowest for length of tuber (36.21). Sixteen sweet potato microsatellite markers (SSR)were used for molecular characterization, which werecapable of detecting 276 alleles with an average of 17.25 alleles per locus. The highest number of alleles per locus was observed for Ib3/31 SSR primer. The number of alleles per locus ranged from 14 to 28 and allelic polymorphism information content (PIC) value ranged from 0.79 for the primer Ib-242 to 0.92 for Ib2/55 with an average of 0.88.A perusal of similarity coefficients clearly reflected that a very high degree of similarity exists between sweet potato genotypesDOP-MIX-93-13 and RS-5 (0.29), on the other hand, the two most distantly related genotypes were DOP-MIX-97-6 and 85-X-04 (0.02).The result of the present study clearly established that the utilization of sixteen selected SSR markers was sufficient for discrimination and unambiguous identification of all the seventeen sweet potato genotypes used.
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    ThesisItemOpen Access
    In vitro propagation of Orchids and Clonal Fidelity Analysis
    (Rajendra Agricultural University, Pusa (Samastipur), 2015) Kumari, Kamni; Kumar, Mithilesh