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2010 - 20132
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Author: Gurpreet Kaur × End date: 2016 × Type: Thesis × Thesis Type: M.Sc ×
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    IMPACT OF ASSIMILATE AVAILABILITY AND ITS UTILIZATION ON SEED BIOMASS IN KABULI CHICKPEA
    (2013) Gurpreet Kaur
    The present investigation was carried out in kabuli chickpea cultivars differing in seed size consisting of two small (BG-1053 and L-550), two medium (GLK-25104 and GLK-28125) and two bold (GLK-27346 and GLK-26155) seeded cultivars. The variations in physiological parameters (biomass accumation, plant height and number of branches) and in activities of enzymes of sucrose metabolism such as invertases (acid and alkaline) and sucrose synthase were estimated in the vegetative (apical leaves, 1st to 3rd intermodal portion of the stem) and reproductive tissues (podwall and seeds) of these cultivars at different stages of crop development. The profound vegetative growth in bold seeded cultivars was the result of their increased height and broader leaves that might be assimilating more photosynthates in them as compared to small seeded cultivars. The higher activities of sucrose metabolizing enzymes in leaves and stem along with higher content of total sugars in these tissues of bold seeded cultivars were might be responsible better availability and utilization of these photoassimilates for increased vegetative growth in them as compared to small seeded cultivars. The lower as well as earlier decrease in activities of invertases and sucrose synthase in podwall of GLK-27346 and GLK-26155 as compared to medium and small seeded cultivars might be helping to channel more sucrose towards the seeds. The rapid decrease in invertase activities in seeds of GLK-27346 and GLK-26155 at 21 days after flowering and higher and sustained activity of sucrose synthase in their seeds upto 35 days after flowering as compared to other culivars indicates longer seed filling duration and higher sink strength in them that might be responsible for their increased seed size. Chickpea, Leaves, Stem, Pod wall, Seed, Seed size
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    ThesisItemOpen Access
    CHARACTERIZATION OF Ustilago segetum (Pers.) Roussel tritici Jensen CAUSING LOOSE SMUT OF WHEAT
    (Punjab Agricultural University, Ludhiana, 2010) Gurpreet Kaur
    Thirty five isolates of the Ustilago segetum (Pers.) Roussel tritici Jensen were characterized on the basis of pathogenicity using Nielsen’s Canadian differential set and other cultivated wheat varieties. The isolates could fall in 6 and 23 categories on the individual basis of their reaction on Canadian differentials and cultivated wheat varieties, respectively. However, 35 isolates could fall into 29 groups on the basis of their reaction collectively on Canadian differential set and cultivated wheat varieties. Grouping of races in most of the cases could not be attributed to the area from where they were collected and also the type of wheat from which initially collected. Only some of the isolates, LS11, LS13, LS16, LS18, LS32 and LS35 collected from Triticum aestivum from Himachal Pradesh, Uttar Pradesh, Dhaulakuan, Rajasthan, Jalandhar and Ludhiana (from Triticosecale) fell in different individual groups indicating geographical diversity in the pathogen. Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) profiling were evaluated for assessing the extent of genetic variation among the isolates of Ustilago segetum (Pers.) Roussel tritici Jensen which causes loose smut disease of wheat. Eight random decamer primers and eight ISSR primers were used to characterize twenty four isolates of the pathogen. These isolates were collected from wheat cultivars grown at various locations of North-Western India (Punjab, Haryana, U.P. and Rajasthan). The RAPD and ISSR primers generated a total of 206 scorable bands collectively. All the isolates could be precisely differentiated from each other employing these primers and initially grouped into two distinct clusters. The molecular classification did not correspond with the geographical distribution, host origin of the isolates and groups categorized based on pathogenicity test. ISSR profiling was found superior to RAPD and can be effectively utilized for further characterization of the loose smut pathogen.