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2013 - 20183
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Subject: Agricultural Microbiology ×
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    ThesisItemOpen Access
    STUDIES ON GENETIC CHARACTERIZATION OF PERSIAN WALNUT (Juglans regia L.) GERMPLASM USING MOLECULAR MARKERS
    (UHF,NAUNI, 2018-02) SHAILJA; KAUR, RAJINDER
    ABSTRACTJuglans regia L . commonly known as ‘Akhrot’ and it belongs to family Juglandaceae.Walnut oil contains alphalinolenic acid and linoleic acid.They reduces the risk of cardiovascular diseases. In the present study EST-SSR markers were datamined for Juglans regia L.and were used for polymorphism studies. EST sequences of Juglans regia L.were downloaded from NCBI website (www.ncbi.nlm.nih.gov/nucest). 2000 EST sequences for Juglans regia L. were screened. ESTs containing SSR motifs were extracted out using an online tool, SSRIT (www.gramene.org/db/searches/SSRtool). SSR primers were designed from the EST-SSR containing sequences using PRIMER 3 software (www.frodo.wi-mit.edu/primer3/) and 98 primers were custom synthesized. Polymorphism study was carried out using 35 EST-SSR, 29 Genomic SSR and 30 ISSR primers among 37 genotypes of Juglans regia L. For polymorphism, DNA was isolated from young leaves of all the 37 genotypes using CTAB method (Doyle and Doyle, 1987). 24 primers were informative out of 35 EST-SSR, 19 primers were informative out of 29 Genomic SSR and 22 primers were informative out of 30 ISSR. Jaccard’s similarity matrix was developed and dendrograms were generated using NTSYSpc ver.2.02h to establish the percent similarity among the 37 genotypes of Juglans regia L. With EST-SSRs, two clusters ‘A’ and ‘B’ were obtained. Cluster A was further subdivided into A1 and A2. A1 contained 28 genotypes and A2 contained eight genotypes whereas cluster B contained only one genotype. For Genomic SSR two clusters ‘C’ and ‘D’ were obtained. Cluster C was further subdivided into C1 and C2. C1 contained 33 genotypes and C2 contained three genotypes whereas cluster D contained only one genotype whereas For ISSRs, 37 genotypes were divided into two cluster i.e ‘E’ and ‘F’. Cluster E was further subdivided into E1 and E2. E1 contained 28 genotypes and E2 contained eight genotypes whereas cluster F contained only one genotype. Morpho-physical characters were also studied for diversity study like Time of Bud burst, Flowering time, Degree of Dichogamy, Nut shape, Shell hardness, Nut weight, Kernel weight, Kernel recovery.Eucledia statistical tool is used to calculate the dissimilarity by combining both molecular as well as morphological data.Thus molecular markers and morpho-physical charaters used in the present study revealed a high level of polymorphism in the 37 genotypes of Juglans regia L., revealing their efficiency for diversity analysis studies.
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    ThesisItemOpen Access
    CHARACTERIZATION OF Frankia spp. ASSOCIATED WITH NON-LEGUMINOUS NITROGEN-FIXING PLANTS OF WESTERN HIMALAYA
    (UHF,NAUNI, 2018-03) BHARDWAJ, SONAL; KAUSHAL, RAJESH
    ABSTRACT In recent years, land degradation has increased considerably due to demographic pressure and climatic factors which has resulted in reduction of biodiversity, soil fertility and crop productivity. To overcome the problems of lack of soil fertility in degraded areas, fast growing nitrogen fixing actinorhizal plants are being considered for plantation programme. The studies on actinorhizal associations with prominent non-leguminous species of mid and high hills i.e. Casuarina equisetifolia and Alnus nitida were conducted during 2014-2017. The studies revealed that Casuarina samples harboured more actinobacterial population in root nodules compared to Alnus. Among different media tried, Defined Propionate Minimal (DPM) medium with pyruvate as carbon source was most suitable for the growth of actinobacteria. A total of 33 isolates from both the species were isolated from Solan (mid hills) and Kullu (high hills) districts of Himachal Pradesh. Out of these 33 isolates, only 10 isolates exhibited maximum plant growth promoting traits viz. phosphate solubilization (250.0- 379.2 μg/ml), HCN production, growth on nitrogen free medium, auxin production (15.2-59.1 μg/ml) and siderophore production (44.2-90.2% siderophore unit) as well as antagonism against Fusarium oxysporum, Pythium sp., Rhizoctonia solani and Phytophthora sp. The phenotypic characterization of the isolates showing branched hyphae bearing sporangia, vesicle like structures, non-turbidity of liquid medium and formation of nodules in plant infection tests confirmed their identity with Frankia. The molecular characterization of Inter Transcribed Spacer (ITS) region with selected primers was successful for three isolates (ANG10, ANG11 and CG1). It revealed the similarity of two isolates i.e. ANG10 and ANG11 with Micromonospora sp. (88% and 90%, respectively) and in 23S region with Frankia sp. (91% and 91%, respectively). The ITS region of CG1 isolate showed similarity with Verrucosispora sp. (98%) and in 23S region with Frankia sp. (93%). The sequence similarity was less with Frankia sp., which necessitates the identification of these isolates to be verified with whole genome sequencing. The effect of application of selected isolates on plant growth and soil parameters indicated that inoculation with CG1 isolate for Casuarina equisetifolia and ANG11 isolate for Alnus nitida led to significant increase in shoot-root length, total biomass, total NPK content and their uptake and available NPK content in soil over uninoculated control. Hence, these isolates have enormous potential to be used as multifunctional biofertilizer for enhanced growth of actinorhizal plants and to sustain soil health under mid and high hills of Himachal Pradesh.
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    ThesisItemOpen Access
    STUDIES ON PLANT GROWTH PROMOTING RHIZOBACTERIA ASSOCIATED WITH SEABUCKTHORN (Hippophae rhamnoides)
    (2013) ANIL, KUMAR; SHIRKOT, C.K.
    ABSTRACT The ability of a few soil microorganisms to convert insoluble forms of phosphorus to an accessible form is an important trait in plant growth-promoting bacteria for increasing plant yields. Little is known about the composition of phosphate solubilizing bacterial (PSB) diversity associated with rhizosphere of medicinal plant. Therefore, the present study was aimed to explore the diversity of P-solubilizing bacterial communities colonizing the rhizosphere soil and roots of medicinal plant seabuckthorn grown in natural conditions for the plant growth promoting activity towards the development of microbial inoculants for different crops grown in normal and stressed region. One hundred and six phosphate solubilizing bacteria were isolated by using culture dependent procedure from rhizosphere soil and endorhizosphere of seabuckthorn of two locations viz., Lahaul & Spiti of Himachal Pradesh. All the PSB isolates were screened for plant growth promoting traits (PGPT), including IAA production, siderophore, HCN, ability to grow on nitrogen free medium and antifungal activity. IAA production was detected in 74.52%, siderophore synthesis in 26.42%, HCN in 43.39%, nitrogen fixing ability in 65.85% isolates. Inhibition against A. solani was detected in 46.22% isolates and 25.47% of isolates had ability to inhibit the growth F. oxysporum. Out of total P-solubilizing bacterial isolates, fourteen isolates were selected on the basis of dendrogram derived from similarity coefficient among PGP traits. Isolates LU45* accumulate maximum phosphorus 239.24 μg/ml among selected 14 isolates along with other PGP traits (IAA, Siderophore, HCN, antifungal and lytic enzyme activity), therefore, selected for identification and characterization of different culture conditions for in vitro TCP solubilization. However, isolate T2R was morphologically different among all other isolates with a unique ability to produce red pigment, showed maximum PSI (5.0) and therefore, isolate T2R was also characterized phenotypically, biochemically and molecular based characterization. For net house studies, six isolates with PGPT were evaluated for their effect on early growth of tomato seedlings. Isolate T76* showed maximum per cent increase in root length, shoot length, root & shoot dry weight and vigour index and was also selected for identification. On the basis of results obtained from 16S rDNA analysis, isolate LU45*, T2R, T76* was identified as Bacillus subtilis CKS1, Serratia sp. AS2, Bacillus sp. AS3 respectively. Present study first time reported Serratia sp. from rhizosphere of seabuckthorn. Thus, the ability of performing multifarious plant growth promoting activities in tandem suggest PSB isolates for plant growth promotion and has significance to develop a cost-effective ecofriendly multifunctional biofertilizer.