Browsing by Author "Jagmeet Singh"
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ThesisItem Open Access Effect of spermidine on antioxidant defense system in wheat (Triticum aestivum L.) under high temperature stress(Punjab Agricultural University, Ludhiana, 2021) Jagmeet Singh; Asthir, BavitaIn the present study, the effect of spermidine (Spd) was studied on the antioxidant defense system of three wheat (Triticum aestivum L.) genotypes (Unnat PBW 343, HD 2967 and HD 3086) under high temperature (HT) stress. The analysis was carried out on the seedling raised in laboratory (25oC or 32oC) in the pots filled with field soil for six days and yield parameters in field crop. The crop was sown under three planting conditions i.e. normal (11th November), late (11th December) and very late (11th January). High temperature significantly reduced root/shoot lengths, fresh weight and dry weight of all the three genotypes, whereas Spd mitigated this effect by increasing these attributes. High temperature significantly increased the activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) in shoots of all genotypes. Higher activities of CAT, GPX and APX in Unnat PBW 343 demonstrate their important role in scavenging H2O2. Conversely, high temperature stress led to a significant decline in SOD, CAT, APX and GPX activities in roots with a subsequent increase in diamine oxidase (DAO) and polyamine oxidase (PAO) activities especially in HD 3086 and HD 2967. Spermidine responded to high temperature stress by increasing Spd and spermine levels and decreasing putrescine levels. An increase in MDA and H2O2 content was observed under high temperature stress. However, pretreatment of Spd under HT further elevated activities of DAO, PAO, SOD, CAT, APX and GPX whereas contents of MDA and H2O2 were reduced. In fact, Spd treated seedlings performed better in terms of antioxidant response under HT than seedlings in its absence. Various yield and yield related parameters like plant height, spikelets per spike, tiller count, 1000-grain weight, number of grains per ear head, grain yield and biological yield were decreased in late and very late sown crop. However, Spd application under HT stress increased these parameters. Overall, the wheat seedlings respond to HT mediated increase in antioxidant defense system by altering polyamine catabolism though differentially in three wheat genotypes. Among three genotypes studied, Unnat PBW 343 seems to be better protected against HT stress. Thus, the results suggested that shoots were more resistant against the destructive effects of H2O2 as also indicated by low levels of MDA content under HT stress.ThesisItem Restricted Genetic Variability and Molecular Characterization for Sucrose Synthesis Gene (s) in sugarcane (Saccharum spp. complex)(Punjab Agricultural University, Ludhiana, 2019) Jagmeet Singh; Thind, K.S.In the present studies, a set of one hundred twelve diverse varieties/clones including twelve checks of sugarcane were evaluated for variability, heritability, genetic advance and correlation coefficient. The aim of present study was to study genetic variability and molecular characterization for sucrose synthesis gene(s) in Sugarcane (Saccharum spp. complex). All the genotypes were planted in a augmented design. The observations on eight cane yield, its components traits and twelve quality traits were recorded. Analysis of variance revealed significant differences among clones/varieties for all the traits. For agromorphological traits, 19 new clones were superior than high yielding check variety CoPb-93.For quality traits, 8 new clones superior than quality check variety CoJ-64.Two clones K-11/9 and K-11/4 were recorded as high yield clones than high yielding check variety CoPb-93 and high quality than high quality check variety CoJ-64.Two clones K-31/2 and K-47/115 better in quality with CoJ-64 and at par the yield with CoPb-93.High magnitude of coefficient of variation i.e. PCV and GCV under cane yield and its component traits was recorded for number of shoots at 120 days and cane yield. High heritability coupled with high genetic advance recorded for number of shoots at 120 & 240 days (000/ha) and cane yield (kg/plot).For quality traits, high PCV, GCV and ECV was recorded for fibre (%). The genetic diversity in a set of 124 (112 clones and 12 check varieties) genotypes of sugarcane was assessed for sucrose phosphate synthetase gene with 10 different set of SSR markers. Different polymorphic percentage that shows high level of diversity was obtained in eight SSR markers. Marker A, SPS, SCB07, MSSCIRI and MSSCIR43 showed higher polymorphic percentage (100%).The divergence analysis grouped 124 genotypes into three major clusters. It was observed that more number of clones belongs to Cluster II. In Cluster III, eight clones and one check (CoJ-88) were present. Maximum similarity was observed in K-1/6 and K-1/30, K-3/18 and K-47/93, K-1/9 and K-48/103 .Minimum similarity was observed in K-11/9 and K-12/13, K-47/41 and CoPb-93. The varieties/clones having high yield and sugar and with high genetic diversity were identified that can be utilized for future evaluation on large scale in sugarcane breeding programme.ThesisItem Restricted Management of botrytis gray mold (Botrytis cinerea Pers. ex. Fr.) of chickpea through host resistance and fungitoxicants(Punjab Agricultural University, Ludhiana, 2019) Jagmeet Singh; Upasana RaniBotrytis gray mold caused by Botrytis cinerea is one of the most destructive diseases of chickpea. Maximum disease was observed in seedling inoculated from 5th to 25th February under 100 percent shade condition and disease development was more on PBG 5. Evaluation of chickpea inter-specific derivative lines (115) and germplasm (68) revealed that none of the line possessed high degree of resistance. Six inter-specific derivative lines (9054, 9056, 8007, 8018, 8022 and 8026) and two germplasm lines (GL-93011and GL-98010) showed moderately resistant reaction. Out of forty seven accessions of wild Cicer species, sixteen accessions (C. judaicum ILWC-95, C. judaicum ILWC-182, C. judaicum ILWC-185, C. judaicum ILWC-17148, C. reticulatum ILWC-237, C. reticulatum ILWC-141E, IC-525691, IC-525197, EC-366339, EC-366342, C. pinnatifidum ILWC-225, C. judaicum ILWC-223, C. pinnatifidum ILWC-261, C. pinnatifidum ILWC-0, C. pinnatifidum ILWC-263 and C. pinnatifidum ILWC-212) gave resistant reaction. Out of twenty seven lines derived from the cross of three parents (C. pinnatifidum 188, ICCV 96030 and PBG 1), only three lines (10008, 10009 and 10011) showed C. pinnatifidum 188 specific segment and moderately resistant reaction. These three lines were flanked by primers GA-22, GA-24, GA-105, NCPGR-127 and NCPGR-141. Testing of fungitoxicants by poison food technique (in vitro) showed that maximum per cent growth inhibition of 78.66 and 84.54 respectively was found in azoxystrobin + difenconazole 325 SC even at low concentration of 1 and 5 ppm respectively. Next best fungitoxicant propiconazole 25 EC gave more than 90 percent inhibition at 50 ppm. Similar results were achieved when these fungitoxicants were evaluated for sporulation at their respective concentrations. ED50 value of 1 μl ml-1 was achieved in azoxystrobin + difenoconazole, propiconazole and carbendazim. Non-systemic fungitoxicants were found to be non-effective against the pathogen. Azoxystrobin + difenoconazole 325 SC @0.1 percent with disease reduction of 88.68 per cent over control with per cent disease index of 7.72 as compared to check (68.24%) was followed by propiconazole 25 EC @ 0.1 percent disease reduction of 85.85 per cent over control with per cent disease index of 9.65 per cent.