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2013 - 20192
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Subject: Biochemistry × Author: Ravneet Kaur × Start date: 1966 ×
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    ThesisItemOpen Access
    Biochemical basis of micronutrient deficiency tolerance in triticale x wheat derivative lines
    (Punjab Agricultural University, Ludhiana, 2019) Ravneet Kaur; Bhatia, Surekha
    The present study was aimed to investigate the biochemical basis and molecular marker profile of genes associated with micronutrient uptake in parental lines viz rye, triticale (TL 2908, TL 2942), bread wheat lines (PBW 343, PBW550, HD 2967, HD 3086) and durum wheat lines (PDW 233, PDW 291, WHD 943). Five days old seedlings of these parental lines were transferred to three set of treatments (T1-control, T2- micronutrient deficient (stress), T3-with micronutrient supply (alkaline stress pH-9) for 30 days. Rye and triticale lines have longer, hairy and thick roots with high number as compared to bread wheat and durum wheat lines. Roots and shoots of rye and triticale lines accumulated higher fresh/dry weight than bread wheat and durum wheat lines irrespective of treatments. Both stressed conditions caused reduction in roots/shoots fresh weight and dry weight of all parental lines however, rye and triticale lines accumulated greater biomass under alkaline stress conditions on 21 DAT. Rye and triticale lines had higher phytosiderophore content (118 to 498 µmole of Cu equivalents/gFW) than bread wheat (19 to 112 µmole of Cu equivalents/gFW) and durum wheat (6 to 68 µmole of Cu equivalents/gFW) under different treatments during whole period of experiment. In rye and triticale, it was increased from 7 DAT to 21 DAT and decreased afterward on 30 DAT. However, in bread wheat and durum wheat lines, this increase was found only up to 14 DAT. Increase or decrease in release of PSs from roots of parental lines was positively correlated with the higher micronutrient content in roots (r=>0.9) and shoots (r=>0.8) of these lines. Highest micronutrient efficiency was found in rye (73.62-86.08%) followed by triticale lines (70.61-81.06%), bread wheat lines (36.82-66.14%) and durum wheat lines (29.42-62.38%). Further higher activities of SOD, CAT and CA enzymes in rye and triticale lines than bread wheat and durum wheat lines were found which was probably linked with higher micronutrient efficiency corresponding to efficient utilization of micronutrients in rye and triticale lines. Rye and triticale also exhibited higher activities of NAAT and MAS enzymes. Parental lines and triticale X wheat derivative lines were tested for presence of 5R chromosomes using seven 5R chromosome specific markers. Only three markers (SCM 138, KU 140, KU 640) showed expected polymorphism in parental lines were further used to evaluate triticale X wheat derivative lines. Fifteen rye specific primers of Ids3 gene were designed after in-silico sequence analysis. Five primers showed polymorphism in parental lines as well as triticale X wheat derivative lines. Higher release of PSs was estimated from the roots of triticale X wheat derivative lines which were positive for Ids3 and 5R chromosome specific markers. Fourteen triticale X wheat derivative lines with higher PSs under micronutrient deficient conditions, were selected for their further utilization in wheat breeding program for improvement and development of efficient varieties with higher nutritional value.
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    ThesisItemRestricted
    BIOCHEMICAL AND MOLECULAR ANALYSIS OF WHEAT INVERTASE
    (2013) Ravneet Kaur
    The present investigation was aimed to study the interactive effect of high temperature (HT) and thiourea (TU) on various morpho-physiological and biochemical parameters in four wheat (Triticum aestivum L.) cultivars viz. C 306, C 273, PBW 343 and PBW 534. High temperature caused reduction in root/shoot length and dry weight while application of TU was effective in improving both root/shoot lengths and dry weight. High temperature caused increase in invertase activities in both root and shoot in correspondence with an increase in total sugars, reducing sugars and decrease in non reducing sugars. Thiourea alleviated HT response by further elevating invertase activities which lead to higher seedling dry mass (soluble sugars and proteins). Inhibitory effect of iodine and Hg+2 on invertases confirmed the presence of –SH group at the active catalytic site of enzyme. The differential response to metal ions suggested distinctive nature of invertases in four cultivars. High temperature also disrupted membrane stability parameters by increasing TBARs content and membrane permeability in root/shoot whereas TU application ameliorated this effect by reducing TBARs content and membrane injury in wheat seedlings. Sequence analysis of wall bound invertase was done using forward and reverse primers based on nucleotide sequence of Ivr1 gene. For this genomic DNA was extracted, amplified and sequenced. Polymorphism such as SNPs (single nucleotide polymorphism) and indels (insertions or deletions) were worked out and primers redesigned based on sequence polymorphism. Redesigned primers showed very slight expected dominant polymorphism in the studied cultivars due to A, B and D genomes of wheat