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20183
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Subject: Botany × End date: 2018 × Start date: 2018 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Morpho-physiological characterization of Mexican wheat landraces for traits of Economic importance
    (Punjab Agricultural University, Ludhiana, 2018) Ankita; Sarlach, R.S.
    The present research work on “Morpho-physiological characterization of Mexican wheat landraces for traits of Economic importance” was carried out to explore the genetic diversity of landraces for drought and salinity stress tolerance. The study was carried out at wheat laboratory and experimental area of Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana during 2015-16 and 2016-17. A set of 1161 Mexican wheat landraces was procured from CIMMYT, Mexico and was sown in field in augmented block design. The landraces set was narrowed down to a smaller set on the basis of their yield potential and seed availability. Selected 177 Mexican wheat landraces were subjected to salinity and drought stress conditions. To find the salinity stress tolerance among Mexican wheat landraces, they were subjected to different concentration of sodium chloride (0, 25mM, 50mM, 75mM, 100mM, 125mM and 150mM) in laboratory. Among different concentration of NaCl, 125mM was found to be the optimum dose for screening. Similarly, to find the drought stress tolerance among Mexican wheat landraces, these were subjected to different concentration of PEG (6000) 0 (control), 2%, 4% 6% 8%,10%,12%,14%,16% and 18%.Dose of 14% was found to be the optimum dose for further screening. The landraces selected from the laboratory screening at seedling level were further evaluated for drought stress (irrigated, restricted irrigated and rainfed conditions) and salinity stress tolerance (Rajpura and Rattakhera, Sri Muktsar Sahib) under actual field conditions and in pots with simulated salinity stress conditions (control, 120mM and 240mM NaCl).The soil of Sri Muktsar Sahib was slightly alkaline having pH 8.1 and high EC (0.948 dS/m). The district contains high salinity and water logged area. And the soil of Rajpura was alkaline having pH 8.5 and high EC (1.97 dS/m). The landraces MICH89.4.28, MICH89.5.5, VERY LATE, HGO94.10.7, MEX94.19.52 performed well under actual field and simulated salinity stress conditions. The drought stress was created by withholding of irrigations (rainfed conditions) pre-irrigation before sowing and subjected to rainfall for water requirements, irrigated conditions (regular recommended irrigation) and restricted (1-2 irrigation after sowing). The morpho-physiological data was recorded. The landraces TXL92.1.1.58, PBL94.14.17, HGO94.5.124, HGO94.5.130, HGO94.9.2.29 and HGO94.8.113 performed well under drought stress conditions. These landraces can be used for introgressing the salt and drought tolerance traits into commercial wheat cultivars for development of tolerant wheat varieties.
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    ThesisItemRestricted
    Partitioning of zinc and its associated metabolites in diverse rice (Oryza sativa L.) genotypes
    (Punjab Agricultural University, Ludhiana, 2018) Avneet Kaur; Nirmaljit Kaur
    The present investigation entitled “Partitioning of zinc and its associated metabolites in diverse rice (Oryza sativa L.) genotypes” was undertaken in the Department of Botany, Punjab Agricultural University, Ludhiana during 2016-17. Seeds of sixteen genotypes with diverse zinc content were procured from the Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. The studies were conducted in two experiments, in the first experiment sixteen rice genotypes were raised in the nursery and; physiological and biochemical parameters of rice genotypes were quantified from 35-days old seedlings. The chlorophyll pigments, hill activity, total soluble sugars, total soluble proteins, free amino acids, starch and superoxide dismutase (SOD) activity were recorded higher in PR113 and PR121, whereas these were lower in RYT Biofort1 and RYT 3403 as compared to the rest of the genotypes. Grain weight, grain yield and grain zinc uptake also followed similar trend. Hence, PR113 and PR121 were characterized as zinc efficient, whereas, RYT Biofort1 and RYT 3403 as zinc inefficient. These zinc efficient and zinc inefficient genotypes were put to further experimentation. The zinc content and zinc associated traits were quantified during three stages of development: maximum tillering, anthesis (50% flowering) and maturity. The chlorophyll content, hill activity and SOD activity increased significantly from maximum tillering to anthesis stage and these parameters were also higher in zinc efficient genotypes as compared to zinc inefficient genotypes. The total soluble sugars, total soluble proteins, free amino acids and starch increased significantly from maximum tillering to anthesis stage, whereas decreased from anthesis to maturity. These metabolic reserves were higher in zinc efficient genotypes as compared to the zinc inefficient genotypes. The plant height, leaf area, flag leaf area, leaf weight, number of tillers and internodal length was also higher in zinc efficient genotypes as compared to the zinc inefficient genotypes. The leaf, tiller, spike and grain were separated at each representative stage of growth for quantifying weight, zinc content and zinc uptake. A higher dry matter accumulation as well as zinc remobilization from the vegetative to reproductive parts of the plant was observed in the zinc efficient genotypes as compared to the inefficient ones.Panicle characteristics, viz., panicle length, panicle number per m2, filled spikelet percentage and percent grain filling were high in zinc efficient genotypes, whereas low in zinc inefficient genotypes. On the contrary, panicle sterility was high in the zinc inefficient genotypes. Yield and yield contributing traits, viz., test weight, grain weight per plant, grain yield and harvest index were high in the zinc efficient genotypes as compared to the zinc inefficient genotypes. Based on the present investigation, PR113 and PR121 have been characterized as zinc efficient and RYT Biofort1 and RYT 3403 as zinc inefficient genotypes.
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    ThesisItemOpen Access
    Morphophysiological basis of manganese deficiency tolerance in progenies derived from wheat  triticale crosses
    (Punjab Agricultural University, Ludhiana, 2018) Ramanjit Kaur; Sarlach, R.S.
    Manganese (Mn) is one of the leading micronutrient deficiency disorders in alkaline and calcareous soil of Punjab due to wheat-rice crop rotation system. Mn efficiency is an ability of a plant to have greater Mn uptake in the Mn deficient soil too. This study was designed to refine the half seed technique for screening of efficient progenies derived from wheat x triticale crosses at seedling stage on the basis of specific visual symptoms of Mn deficiency in the pot experiment and then validated in the Mn deficient field. Taking in account its traits to be introgressed from rye and the preliminary indications of micronutrient deficiency tolerance, the proposed study has been devised to explore the potential of Mn deficiency tolerance in the germplasm. In the first pot experiment, nine wheat genotypes were sown using half and full seed under Mn deficient conditions. Being most sensitive to Mn deficiency durum wheat cultivar PDW 233 showed earliest symptoms in half seed rather than full seed. It helped to validate the method of screening. This novel method of screening was used to evaluate lines derived wheat x triticale crosses. Durum wheat, bread wheat and triticale were used as standard sensitive, moderate and tolerant control respectively. Out of seventy two lines, only forty two were selected on the basis morpho-physiological traits like root-shoot length (cm), dry matter accumulation (g), days to germination (DTG), vigour index, relative growth rate, days to deficiency symptom appearance, yield contributing traits, Mn indices and stress tolerance index. Biochemical analysis of selected lines was carried out later in laboratory. Lines derived from first cross TL2908/2*CS(S)//PBW343 were 3-TL to 5-TL, 8-YRR-TL, 12-TL, 14-TL, 15-YRR-TL, 21-TL to 26-TL, second cross T3048/2*CS(S)//PBW343 were 28-T3048 to 38-T3048, 43-T3048, 46-T3048 to 48-T3048, 51-T3048, third cross 54-T3065/2*CS(S)//PBW343, forth cross 56-T3048/2*CS(S)//DBW17 to 59- T3048/2*CS(S)// DBW17, 61-T3048 to 63-YRR-T3048 and fifth cross 65-T3021/2*CS(S)//PBW550 to 66-T3021/2*CS(S)//PBW550, 68-T3021, 71-T3021 to 72-YRR-T3021 were evaluated as Mn efficient lines. These lines can be used for further processing to introgress Mn efficiency and released at commercial level as Mn deficiency tolerant varieties.