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ThesisItem Restricted Mapping productivity related traits in Brassica rapa L.(Punjab Agricultural University, Ludhiana, 2020) Kamboj, Shefali; Dhillon, S.K.In the present study, a set of 130 B. rapa – B. cossoniana introgression lines (ILs) were characterized for key productivity related traits: plant height, main shoot length, number of primary branches per plant, number of secondary branches per plant, number of siliquae on main shoot, siliqua length, number of seeds/siliqua, seed size, seed yield per plant and oil content. Analysis of variances indicated significant genotypic variation among the tested introgressed genotypes for all the traits. Correlation matrices indicated positive correlation of secondary branches with primary branches (r = 0.581**) and seed yield per plant per se (r = 0.231**). Number of siliquae on main shoot exhibited positive association with plant height (r = 0.332**), primary branches (0.229**), secondary branches (r = 0.167*) and main shoot length (r = 0.417**). Seed size exhibited positive correlation with oil content (r = 0.354*) and siliqua length (r = 0.170*). Genome wide association studies indicated significant marker trait associations for the target traits across all the 10 chromosomes of B. rapa. It was possible to identify 30 genes comprising two for plant height, four for main shoot length, five for primary branches, six for secondary branches, one for siliquae on main shoot length, four for siliqua length, three for seeds per siliqua, two for seed size and three for oil content. It could not be possible to predict the genes for seed yield per plant per se. Gene involved in inhibiting shoot branching (CYP711A1) and vegetative development (2-OG) were predicted for plant height, whereas for main shoot length gene involved in flower development (ARF4, BIN2 and AtMBD9) were predicted. Genes involved in maintenance of the shoot apical meristem (SPC25), determinacy of floral meristem (PWR, KNU) were predicted for primary branches, whereas for secondary branches genes involved in controlling levels of auxins (BIN2, B ALPHA) and degradation of CKs (CKX1), maintenance of the activity of shoot meristem (LOG1) were predicted. Gene promoting flowering in the shoot apical and axillary meristems (AGL72) were predicted for siliquae on main shoot whereas genes involved in floral termination (LFY) and cell wall thickening (NAC) were predicted for siliqua length. Genes involved in embryogenesis (RCE1, FACKEL, HB2, EMB1027) were identified for seed related traits. For oil content, gene involved in vesicle transport (EMB1441), for synthesis of 18:2 fatty acids (FAD2), seed oil accumulation (OLEO4) were predicted. The present investigation has helped to establish phenotypic variations and prediction of candidate genes for key productivity related traits in the introgressed genotypes of B. rapa. These genes can be validated and exploited in future breeding programme.ThesisItem Open Access Morphological and molecular profiling of interspecific derivatives of Cicer arietinum L. x C. pinnatifidum(Punjab Agricultural University, Ludhiana, 2020) Salaria, Sonia; Bindra, ShaylaIn the present investigation, a set of 158 interspecific derivatives, derived from Bushy Mutant x ILWC 0 (C. pinnatifidum) cross were evaluated along with their parents during 2018-19 and 2019-20. Analysis of variance revealed significant differences among the derivatives for all the traits studied. Various superior derivatives were identified for different traits. GLWP 142 was found to be promising for seed yield per plant. High to moderate heritability and genetic advance was observed for plant height, number of pods per plant, biological yield per plant and 100-seed weight. These traits also exhibited significant positive correlations with the seed yield per plant implying their importance in selection for high seed yield per plant. Path analysis revealed significant positive direct effects of number of pods per plant, 100-seed weight, number of seeds per pod and biological yield per plant towards seed yield while the indirect effects for various traits were prominent via biological yield. D2 analysis grouped 158 derivatives and their parents into 13 clusters. Only one derivative (GLWP 55) was found resistant and 45 derivatives were found moderately resistant to Ascochyta Blight. None of the resistant derivative was found for Botrytis Grey Mould while 24 derivatives gave moderately resistant reaction. The genotyping-by-sequencing (GBS) analysis identified 1409 polymorphic SNP markers. Graphical genotyping confirmed the introgressions of varying degree in derivatives from wild parent ILWC 0 (C. pinnatifidum). Single marker analysis identified seven SNP markers linked to Botrytis Grey Mould which could be further utilised for its mapping. The promising derivatives identified for yield and its component traits along with the disease resistance can be utilized in further chickpea breeding programmes for development of high yielding cultivars.ThesisItem Open Access Molecular-genetic characterization of irradiated „B‟ genome introgression lines of Brassica napus(Punjab Agricultural University, Ludhiana-, 2020) Kaushal, Swas; Indu RialchBrassica napus introgression lines (ILs), with B-genome segments from Brassica carinata irradiated with gamma irradiations were assessed genetically for extent of introgression and phenotypically for both determinate inflorescence and pod shatter resistance. GMATA software was used to develop set of B-genome specific primers from the B-genome specific regions in the introgressed B. napus .Genotyping with B-genome-specific SSRs allowed the identification and delineation of substituted B-genome chromosome fragments on recipient A- and C- genome chromosomes of B. napus. Some introgression lines contain one or two fragments of the B-genome chromosome spread across different chromosomes. Size of the substituted B-genome fragment varied from 0.36 Mbp (C8, IL 5) to 7.74 Mbp (A10, IL 3). In terms of proportions, the substituted segments ranged between 5.6 % (C6, IL 2) to almost 33.3 % (A9, IL 22) of the actual size of the recipient A-/C-genome chromosomes. Bchromatin substitutions were interstitial only in a few instances while they were terminal in most of the ILs. Determinacy had a great impact on the flowering habits by shortening the flowering phase and days to maturity in irradiated B. napus introgression lines. Assessment of morphological data indicated a relatively earlier onset of flower termination in determinate genotypes as compared to indeterminate commercial cultivars. The early maturing ILs were IL13 (111 days), IL68 (119days), IL 46 (121days) and IL 54 (122days) whereas introgression lines with high pod shatter energy were IL28 (6.4 mJ), IL29 (5.8 mJ), IL69 (7.5 mJ) and IL78 (6.7mJ). Introgression lines with determinate habit of plant growth and high pod shatter energy appeared to be very promising germplasm tools for future breeding.ThesisItem Open Access Association mapping for Ascochyta blight, Botrytis grey mould and yield contributing traits in a Reference Set of chickpea (Cicer arietinum L.)(Punjab Agricultural University, Ludhiana-, 2020) Aiswarya S. Kumar; Sarvjeet SinghEvaluation and exploitation of genetic diversity is crucial for crop improvement programmes for the efficient utilization of potential genetic sources for desirable traits. The chickpea Reference Set comprising 288 accessions used in this study, constituted by ICRISAT, Patancheru, represents the diverse global composite collection of chickpea and is a reliable source for diversity. The present study was conducted at the Experimental Farm and Laboratories of Pulses Section, Dept. of Plant Breeding & Genetics, PAU, Ludhiana, Punjab during rabi seasons of 2018-19 and 2019-20. The experimental material was evaluated for resistance against Ascochyta blight and Botrytis grey mould diseases, yield and yield contributing traits to identify potential donors and identify associated QTLs under north Indian conditions using association mapping. The yield and contributing traits were evaluated under two phosphorus levels; Low-P (no phosphorus application) and High-P (40 kg/ha P2O5) for two consecutive years in Alpha Lattice design using two replications. One genotype ICC 1915 having high level of resistance to Ascochyta blight and one genotype ICC 6579 having moderate level of resistance to Botrytis grey mould were identified as promising donors for respective diseases. Days to 50% flowering, plant height, number of pods, seeds per pod, 100-seed weight and biological yield showed high to moderate levels of broad sense heritability and genetic advance, implying high response to selection. The traits namely number of secondary branches, number of pods, biological yield and seed yield can be effectively used for selection under low-P regime. Significant and positive correlations were observed between seed yield and these contributing traits. Genotypes namely ICC 5639, ICC 7413, ICC 11584, ICC 13357, ICC 9590, ICC 2072 and ICC 4418 were identified as phosphorus use efficient based on their better performance for yield and yield contributing traits under Low-P compared to high-P conditions. However, association studies failed to establish any Marker Trait Associations (MTAs) for disease resistance and yield contributing traits.ThesisItem Open Access Performance of inbred lines and their hybrids in maize for protein quality and β-carotene(Punjab Agricultural University, Ludhiana-, 2020) Harpreet Kaur; Gill, Gurjit KaurMaize (Zea mays L.) is an important cereal crop for livestock, feed and nutrition, worldwide. Sixty hybrid combinations of maize were generated through Line x Tester mating design using fifteen lines of LM13 versions and four testers of LM14 versions as parental material along with two standard checks PMH1 and HQPM to study combining ability, heterosis and Genotype x Environment interactions. The parents, hybrids were evaluated along with two standard checks during kharif 2018 and spring 2019 at Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana and Regional Research Station, Gurdaspur. Data for eight agronomic and five biochemical parameters were recorded. The mean sum of square due to year, location, genotype, parents, crosses and parents vs crosses for all agronomic traits were significant except days to maturity as well as for all biochemical traits except starch content. Among female line 13CLO-6, 13CLO-14, 13CLO-15 and 13CLO-16 were good combiner for ear length, ear girth, yield per plot, 1000 kernel weight and shelling %. Among the testers, 14CLO-1 and 14CLO-3 were found good combiner for all yield and yield contributing traits. For biochemical traits, line 13CLO-5 was good combiner for tryptophan, starch and oil content,13CLO-15 was good combiner for protein and β- carotene content. Tester 14CLO-3 was good combiner for tryptophan and β- carotene. Among crosses viz., (L9 X T2, L12 X T2, L14 X T3, L4 X T4, L8 X T4 and L13 X T4) were having significantly better specific combining ability effects for days to maturity, ear length, ear girth, yield per plot,1000 kernel weight and shelling %. Crosses viz., (L1 X T1, L6 X T2, L3 X T4, L14 X T2, L11 X T3 and T8 X T4) were also significantly better specific combiner for biochemical traits like protein, tryptophan and β- carotene contents. Top five crosses were (13CLO-3 X 14CLO-4, 13CLO-14 X 14CLO-3, 13CLO-15 X 14CLO-4, 13CLO-6 X 14CLO-2 and 13CLO-2 X 14CLO-4) having significant and desirable SCA effects and heterosis for most of the traits indicating potential to exploit hybrid vigour for breeding programme. All the converted lines, testers and hybrids showed the presence of crtRB1 and o2 genes at 543 bp band and 150 bp band respectively. The validity of the results promises that the hybrids generated are nutritionally enriched.ThesisItem Open Access Identification of quantitative traits loci (QTLs) for popping traits and kernel size in maize(Punjab Agricultural University, Ludhiana, 2020) Sukhdeep Kaur; Rakshit, SujayPopping traits play an important role in the utilization of popcorn. In this study, the F8 RILs population derived from HKI PC4B (Popcorn) × CML 269 (Normal corn) was characterized for seed and popping traits, and sufficient genetic variability was observed in the RILs and the parents for target traits. The best performing RIL(s) in specific environments like RL4, RL51, RL73 were identified using AMMI analysis. A few RILs were found to be superior to those of parents representing their possible use in popcorn breeding. QTL mapping (CIM algorithms) identified a total of 15 QTLs. Out of these QTLs, five QTLs for traits TW, PEV, PPand FV were mapped consistently across the environments on chr 3, 5, 6 and 9, respectively (R2 16.60 – 29.50 %). A total of 10 QTLs identified were environment specific. Two QTLs each for TW, PEV, PP; one QTL for FV were reported on chr 1, 2, 4, 7and 8, respectively. Based on the average values of the traits, three more QTLs were identified for PP, FV and PEV on chr 3 and 1 (R2 4.71 – 11.06 %). MetaQTL approach integrated QTLs from the earlier studies using BioMercator v4.2. A total of 10 metaQTLs were identified and 229 genes were shortlisted in these regions on expression basis (nineteen genes selected using KEGG pathways). The four metaQTLs were considered important for popping traits having 5-8 QTLs clustered in regions. The QTLs for PEV (two) and seven metaQTLs for traits PP, TW, PEV, FS were observed at chr 1, earlier also QTLs and metaQTLs were reported on chr 1. Therefore considered as an important region in enhancement of popping traitsThesisItem Open Access Characterization of mungbean mutant lines for YMD resistance and key agronomic traits(Punjab Agricultural University, Ludhiana, 2020) Mandahal, Kamalpreet Singh; Bains, T. S.The present study was undertaken to evaluate mungbean mutant lines for key agronomic traits and yellow mosaic disease (YMD) resistance across different seasons i.e. summer and kharif and for the identification of putative genes for YMD resistance in these lines. The experimental material consisted of 21 mutant lines developed from irradiation of seeds of mungbean varieties SML 668, SML 832 and TMB 37. A wide range of variability was observed for plant height, number of clusters per plant, number of pods per plant, number of seeds per pod, 100 seed weight, biological yield, economical yield and harvest index. MML 2637 and MML 2664 were identified as best mutant lines for summer season, while MML 2593 and MML 2664 were identified as best mutant linesfor kharif seasons respectively. MML 2629 and MML 2664 showed potential as dual season lines. All the mutants were highly resistant to YMD. Further, QTLs/genes/markers for Begomovirus resistance were used to identify homologous accessions on mungbean genome. On prediction of protein domains of these accessions, most common motifs were found as NB-ARC, TIR, RdRP and SGS3. A set of 48 primers specific for RdRP and SGS3 gene families were designed and validated to amplify complete coding sequences in resistant mutant and susceptible parent. The presence/absence and sequence polymorphism indicated possible role of these two genes in confering YMD resistance in mungbean.ThesisItem Restricted Evaluation and assessment of molecular diversity among Bt American cotton hybrids(Punjab Agricultural University, Ludhiana, 2020) Mahavir; Paramjit SinghThe present investigation was undertaken to evaluate the performance of Bt American cotton hybrids for various quantitative traits and to assess molecular diversity. Ninety-eight Bt hybrids along with two standard checks namely RCH 773 BG II (Bt hybrid) and PAU Bt 1 (Bt variety) were evaluated in 10 × 10 square lattice design at two locations (Ludhiana and Bathinda) during Kharif 2018. Mean squares for genotypes, locations, and genotype × location interaction were significant for all the characters except for enotype mean squares for plant height and sympods plant-1 ; location mean squares for fiber strength and lint index and genotype × location mean squares for sympods plant-1 . These results suggested the presence of significant variation among the experimental plant material, significant difference among the locations, and profound effect on the expression of seed cotton yield, its components and fiber quality traits. Hybrids namely NCEH-6 BG II, Bio 2510-2 BG II, ACH 177-2 BG II and SWCH 4755 BG II significantly outperformed the standard checks RCH 773 BG II and PAU Bt 1 for seed cotton yield plant-1 . Six hybrids significantly outperformed the check RCH 773 BG II for boll weight; however, fourteen hybrids were recorded significantly higher than that of PAU Bt 1. Similarly, thirty-three hybrids were observed significantly higher 2.5 % span length than the check RCH 773 BG II; whereas, six hybrids were found significantly superior than that of PAU Bt 1. Likewise, superior hybrids were identified for various quantitative traits. The molecular analysis of 96 genotypes showed that genotypes were broadly divided into three main clusters A, B and C. RCH 569 BG II was the most diverse as revealed by dendrogram. Dissimilarity coefficient ranged from 0.005 – 0.20 with mean of 0.08 among different pairs of genotypes and PIC values ranged from 0.00 to 0.57 with mean of 0.17. Clustering pattern suggested that more genetic relatedness is present among the hybrids of some of the seed companies than the hybrids of other companies. The present study has provided a useful insight into performance of Bt American cotton hybrids for various quantitative traits as well as information on molecular diversity among the test genotypes.ThesisItem Open Access Inheritance studies and mapping of yellow mosaic disease resistance in an interspecific cross of mungbean (Vigna radiata (L.) Wilczek) and urdbean (Vigna mungo (L.) Hepper)(Punjab Agricultural University, Ludhiana, 2020) Saini, Pawan; Bains, T. S.Yellow mosaic disease (YMD) is the most vicious viral disease causing more than 85 percent economic losses. Among Vigna species, ricebean (V. umbellata) and urdbean (V. mungo) are known to possess high level and stable resistance to YMD. In the present investigation, an interspecific cross between mungbean cv. ML 267 x urdbean cv. Mash 114 was made for inheritance studies and mapping of YMD resistance. A total of 190 were made, of which eight successfully reached pod development stage with low crossability rate of 4.21 percent. The interspecific cross (ML 267 x Mash 114) recorded lower (16.67 percent) F1 seed germination.The hybrid lethality and hybrid survivability were observed as 60 and 40 percent in F1 generation respectively. The F1 hybrid plants exhibited intermediate phenotype between the parental genotypes with respect to growth habit, leaf colour, stem colour and maturity. The true interspecific hybrids were also confirmed with molecular markers. The F2 population derived from this cross was phenotyped for YMD resistance and segregation ratio revealed presence of two genes with duplicate gene action with chi square value of 7.35 at 0.05 level of significance. Further, a set of newly designed mungbean whole genome sequence (WGS) based SSR markers were used for validation of on different Vigna accessions. The SSR markers showed 100 percent transferability on 25 different accessions of 13 Vigna species. The obtained polymorphic information content value (PIC), effective multiplex ratio (EMR), marker index (MI) and resolving power (RP) suggested their usefulness in different genetic studies. Different Vigna accessions were also phenotyped for YMD resistance and V. glabrescence identified as the most promising YMD resistance source. Out of 250 WGS based SSR markers, 144 markers showed polymorphism between ML 267 and Mash 114 with 57.60 percent markers were polymorphic. These polymorphic markers along with 32 Vigna species specific markers were utilized for bulked segregant analysis (BSA) Out of 144, only one marker SSR 121 showed polymorphism between YMD resistant and susceptible bulk. Further, the SSR 121 marker showed co-segregation in F2 population with YMD resistance. The marker SSR 121 was found to be located at 6 cM distance from YMD resistance locus. The findings of study paved the way for further validation of SSR 121 and its utilization in marker assisted breeding programme in mungbean.
