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Subject: Genetics and Plant Breeding × End date: 2023 ×
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    ThesisItemOpen Access
    Genetic analysis of seed yield and quality traits and molecular characterization for white rust resistance in Indian Mustard [Brassica juncea L. (Czern. & Coss.)]
    (CSK HPKV, Palampur, 2023-08-03) Tiwari, Sunidhi; Kumari, Vedna
    The p esent st entit e “Geneti ana sis o see ie an q a it t aits an mo e a ha a te ization for white rust resistance in Indian Mustard [Brassica juncea L. (Czern. & Coss.)]’’ was a ie o t to congregate information on genetic architecture, combining ability, heterosis and inheritance of white rust resistance. The materials for the investigation comprised of 12 lines, three testers (RCC-4, Donskaja-IV and their F1) and resulting 36 TTC hybrids. These progenies and their parents were grown in randomized complete block design with three replications during rabi 2021-22 at the Experimental Farm of the Department of Genetics and Plant Breeding, CSK HPKV, Palampur (H.P.). Analysis of variance indicated the significance of mean squares due to genotypes for all the traits which revealed the presence of sufficient genetic variability in the existing material. Modified triple test cross analysis exhibited the presence of epistasis for all the traits namely, days to flower initiation, days to 75 per cent maturity, plant height, reproductive phase, number of primary branches per plant, number of secondary branches per plant, siliquae per plant, length of main shoot, siliquae length, seeds per siliqua, 1000-seed weight, seed yield per plant, biological yield per plant and harvest index except for days to 50 per ent owe ing. F the , pa titioning o epistasis e ea e the impo tan e o ‘j ’ t pe o epistasis o a most all the t aits ex ept a s to 50 pe ent owe ing whe eas mean sq a es e to ‘i’ t pe inte a tion we e non significant for most of the traits except number of secondary branches per plant, siliquae per plant, siliqua length, seeds per siliqua, seed yield per plant and biological yield per plant which shows the importance of both ‘i’ t pe an ‘j ’ t pe o epistasis. Re ati e magnit e o a iti e omponent D) was p e ominant o e dominance component (H) for most of the traits except reproductive phase, number of secondary branches per plant, siliquae per plant and biological yield per plant indicating the relative importance of fixable type of gene action in their inheritance. Analysis of variance for line× tester revealed the presence of substantial genetic variability. Analysis of variance for combining ability indicated significant differences among hybrids for all the traits studied. The genotype DRMR 2017 was found to be good general combiner for nine traits followed by RSPR-03 for eight traits and Pusa Mehak for seven traits. Five crosses viz., Pusa Tarak × Donskaja-IV, Kranti × Donskaja-IV, RSPR-03 × Donskaja-IV, DRMR 2017 × RCC-4 and Urvashi × Donskaja-IV exhibited higher per se performance, significant SCA effects and heterobeltiosis for seed yield per plant. Two crosses namely, Urvashi × Donskaja-IV and Pusa Tarak × F1 showe ow g osino ate ontent ˂30 µmole per gram of defatted seed meal) and only one genotype viz., Pusa Karishma showed low erucic acid ˂ 2 pe ent). To study the inheritance of white rust resistance, two crosses (RCC-4 × Donskaja-IV and RCC-4 × Heera) were evaluated. In cross RCC-4 × Donskaja-IV, dominant epistasis (12:3:1) was observed while in cross RCC-4 × Heera, complementary epistasis (9:7) was observed. Molecular characterization revealed that intron polymorphic (IP) markers viz., At5g41560 and At2g36360 were highly linked to white rust resistance loci AcB1-A4.1 and AcB1- A5.1 and could be helpful in marker assisted selection for white rust resistance in Indian mustard.
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    ThesisItemOpen Access
    Induced mutagenesis and molecular characterization of elite mutants for grain quality in bread wheat (Triticum aestivum L.)
    (CSK HPKV, Palampur, 2023-06-23) Rana, Amit; Rana, Vijay
    Present studies were conducted with four wheat varieties viz., HS 490, HPW 89, HPW 360 and HPW 251, mutagenized using 175 Gy, 200 Gy, 225 Gy, 250 Gy, 275 Gy & 300 Gy of gamma rays (γ) and 0.3%, 0.5%, 0.7%, 0.9%, 1.1% & 1.3% of EMS to assess their mutation effectiveness and efficiency, spectrum of induced macro mutations in M1 and M2 generation at the Experimental Farm, Rice and Wheat Research Centre, Malan during Rabi 2020-21 and 2021-22. Results showed similar trend of reduction in different parameters with increase in dose/concentrations of both mutagens under lab and field conditions in M1 generation. The LD50/LC50 values of four wheat varieties varied between 290-315 Gy and 0.90-1.35% in case of γ-rays and EMS under lab conditions whereas 240-290 Gy and 0.50-1.10% in case of γ-rays and EMS under field conditions. HPW 251 was found to be more sensitive to both mutagens whereas, HPW 89 emerged as relatively less sensitive to γ-rays and HS 490 to EMS. These results indicated higher sensitivity of semi-hard varieties to mutagens as compared to soft-textured varieties. In M2 population of 18,862 plants, a broad spectrum of chlorophyll mutants (0.949%) and morphological mutants (4.135%) were observed. Mutagenic effectiveness and efficiency showed that highest estimates were found at higher concentrations, but the estimates changed non-linearly with increase in concentrations over all four varieties for both the mutagens. Overall, HPW 251 was found to be most sensitive for mutagenic treatments as compared to HPW 360, HPW 89 and HS 490. EMS caused higher shift in magnitude of all the parameters studied as compared to γ-rays. Based on LD50, three doses (250 Gy, 300 Gy & 350 Gy) of γ-rays were used for inducing mutations in wheat variety HPW 89. Five mutagenic generations viz., M1, M2, M3, M4 and M5 of HPW 89 were raised and studied using Rabi seasons and off-seasons through 2019-2022 at the Experimental farm, RWRC, Malan; HAREC, Kukumseri and IIWBR Regional Station, Dalang maidan, L&S to select agro-morphologically superior, disease resistant and better-quality mutants. Presence of significant variation among 293 M4 mutant lines indicated the scope of selecting desirable mutants for various agro-morphological and quality traits. High phenotypic coefficient of variation and genotypic coefficient of variation as well as high estimates of broad sense heritability coupled with high genetic advance for flag leaf length, flag leaf area, peduncle length, biological yield/plant and grain hardness that selection based on these traits would be effective and rewarding. Days to 50% flowering, days to 75% maturity, biological yield/plant, harvest index and grain hardness emerged to be suitable selection criteria for grain yield improvement on the basis of correlation and path analysis. Out of 108 semi-hard elite mutants, 8 mutants viz., Mut9, Mut17, Mut58, Mut104, Mut109, Mut126, Mut179 & Mut195 were found superior with higher grain hardness, better grain appearance score, sedimentation value and protein content as compared to parent variety HPW 89. These mutants can be further subjected to multi-location testing before channelizing them into the breeding programmes. Overall, two mutants viz., Mut9 and Mut17 were found promising for grain yield, resistance to yellow rust and powdery mildew and desirable quality parameters. Molecular characterization of 108 semi-hard mutants showed presence of both pina and pinb genes. However, mutants having higher grain hardness as compared to parent variety HPW 89 suggested mutations in one or both genes and ma
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    ThesisItemOpen Access
    Molecular diversity analysis and genetics of some morpho physiological and biochemical traits associated with moisture-stress tolerance in bread wheat (Triticum aestivum L.)
    (CSK HPKV, Palampur, 2023-03-25) Anubhav, Shubhanshu; Rana, Vijay
    The present investigation entitled ‘Molecular diversity analysis and genetics of some morpho-physiological and biochemical traits associated with moisture-stress-tolerance in bread wheat (Triticum aestivum L.)’ was conducted to identify morpho-physiological and biochemical traits associated with moisture-stress tolerance and analyze genetic diversity at morphological and molecular level. Experimental material for diversity studies comprised of 56 genetically diverse wheat genotypes; including some high yielding, drought tolerant lines, synthetics, local collections, recombinant inbred lines of a drought tolerant cultivar C 306. Experimental lines were evaluated for different traits in alpha-RBD design with three replications under irrigated (E1) and moisture-stress (E2) field conditions during Rabi 2017-18. A modified TTC analysis comprising 48 progenies; 16 lines and 3 testers was conducted under controlled irrigated (E1) and moisture-stress (E2) conditions during Rabi 2018-19. Significant genetic variability was observed for days to 50% flowering, flag leaf area (FLA), specific leaf area (SLA), specific leaf weight (SLW), relative water content (RWC), grain growth rate I (GGR-I), grain growth rate II (GGR-II), stem reserve mobilisation (SRM), tillers/ plant, grains/ spike, 1000-grain weight, biological yield/ plant, dry matter accumulation (DMA), grain yield/ plant, harvest index and proline content. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) along with high heritability and moderate genetic advance were recorded for proline content under E1 and E2. Grain yield/plant showed significant positive correlation with tillers/plant, 1000-grain weight, biological yield/plant, DMA and harvest index. Biological yield/ plant and harvest index appeared to be the best selection indices for increasing grain yield owing to high direct and indirect effects of these traits in path analysis. Under E1 first six principal components revealed 72.40 % and under E2 first five components explained 71.6 % of total variability. Variation for proline content contributed the maximum to the observed genetic divergence under both conditions. Congruence between morpho-phyiological and SSR data was observed under both the environments. Forty-six out of 56 test genotypes were common among molecular and morphological clusters under moisture-stress, whereas 39 genotypes were common under irrigated conditions. Genotypes SYN 105, IC 36737, HS 562, IC 594376 and VL 907 under irrigated conditions and genotypes viz. IC 322025, HS 490, VHC 6081, VHC 6127, SYN 103, VL 892, VHC 6413, C 306, VL 907, HPW 236 and SYN 117 under moisture-stress conditions were most diverse. STRUCTURE divided the experimental lines into two major populations. Modified TTC analysis was used to detect epistasis and estimates of additive and dominance components of variance for observed phenotypes, which indicated that mean squares due to epistasis were significant for all the traits except SLW and relative water content under irrigated conditions (E1) and FLA under (E2). Additive × Additive (i) type interactions were significant for GGR-I and tillers/ plant under E1 and E2 conditions while j+l type interactions were significant for all the traits except SLW and RWC under irrigated conditions (E1) and RWC under E2. The average degree of dominance (H/D)1/2 revealed similar gene action for 1000-grain weight and GGR-II under both E1 and E2. The comparison of estimates of genetic parameters using Line × Tester and Triple test cross indicated the role of overdominance in genetic control of traits namely, grains/spike, grain growth rate I and proline content under both the environments E1 and E2. Combining ability analysis revealed VHC 6413, HS 562, NIAW 1415, WH 1105 as good general combiners for FLA, GGR- II, grains/ spike, 1000-grain weight; Syntehtic 107 and NIAW 1415 for SRM; VHC 6081 and VHC 6127 for tillers/plant; HS 490,VHC 6127 and HS 507 for DMA; VHC 6127, HS 490, NIAW 1415 and NI 5439 for grain yield/plant; HS 562 and Synthetic 107 for harvest index; HS 507, Synthetic 107, Synthetic 112 and NIAW 1415 for proline content under both E1 and E2. HPW 89 x VL 907 recorded positive significant SCA effects for GGR- II; HPW 349 × VL 907 and HS 562 × HPW 368 for stem reserve mobilisation and VHC 6127 × HPW 368 for grains/spike and dry matter accumulation. These crosses were found promising and could be utilized for developing high yielding drought tolerant lines.
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    ThesisItemOpen Access
    Stability analysis for yield traits and association mapping of quality traits in oat (Avena sativa L.)
    (CSK HPKV, Palampur, 2023-03-09) Sanadya, Sanjay Kumar; Sood, V.K.
    Population growth, hunger and climate change are the major problems in the world. Therefore, a paradigm shift in agriculture is required to explore neglected and underutilized crop species that possess agronomic, nutritional and climate-resilient traits. Harnessing diverse oat genetic resources and development of stable cultivars are the sustainable solution to overcome these problems to some extent. Therefore, experiment was carried out to identify yield stable oat genotypes in organically and conventionally managed fields in the North Western Himalayas using AMMI and GGE biplot analysis and facilitate genetic dissection of quality traits employing ddRAD based GWAS approach. Ninety-six diverse oat genotypes were tested in five environments (year-production system combinations) using 12×8 alpha lattice design with three replications. Pooled ANOVA showed significant genotypic, environmental and GEI effects, suggesting GEI can be assessed in this population. Conventional system had higher yield over organic system across years. Environment and GEI were the major source of variation for all traits except dry matter percentage. Seed yield per plant showed positive significant association with biological yield per plant and harvest index whereas green fodder yield per plant exhibited positive significant association with number of leaves per plant and dry matter yield per plant. Genotypes SKO-190, UPO-119, OS-92, HJ-8, Choripatti and EC-523890 for seed yield per plant and HFO-878, HFO-502 and PLP-14 for green fodder yield per plant were found to be widely adapted. On the basis of polygon view of the GGE biplot, two mega-environments (MEs) were identified with winning genotypes ADG-96 and IG-03-205 in ME-1 and SKO-190, EC-605837, PO-1 and KUE in ME-2 for seed yield per plant whereas JPO-38, IG-03-205 and UPO-119 in ME-1 and SKO 28, RO-19, UPO-102 and JHO-99-2 in ME-2 for green fodder yield per plant. Genome-wide 35,262 SNP markers were used for the identification of genomic loci associated with five grain and forage quality traits phenotyped in different production systems across years. Distribution of SNPs ranging from 998 (chromosome 6D) to 2945 (chromosome 1A) with SNP density ranged from 1.94 per Mb to 5.60 per Mb window size. Population structure and kinship matrix analysis divided population into three groups with some admixtures indicating sufficient genetic variation. Total 31 significant marker-trait associations were detected across twenty one chromosomes for five quality traits. Out of which 6, 3, 9, 9 and 4 were identified for ADF, NDF, β-glucan content, crude protein content and crude protein yield per plant, respectively and explained 0.18 to 17.87% of total phenotypic variation. Twenty putative genes were found to be associated with QTLs linked with quality traits (100 Kb either side). Out of 31 QTLs, 10 QTLs explained more than 10% of total phenotypic variation thus these can be considered as major QTLs indicating a potential for using these markers in genomic assisted oat breeding programme.
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    ThesisItemOpen Access
    Genetic analysis of hybrid fertility and yield contributing traits in indica, japonica and wide compatibility genotypes of rice (Oryza sativa L.)
    (CSK HPKV, Palampur, 2023-01-26) Kaur, Jeevanjot; Bhardwaj, Neelam
    The present investigation entitled “Genetic analysis of hybrid fertility and yield contributing traits in indica, japonica and wide compatibility genotypes of rice (Oryza sativa L.)” was undertaken to get the information on nature and magnitude of gene action, combining ability and heterosis and thereby indentifying potential parents and cross combinations for yield, cold tolerance and disease restistance that could support further improvements of rice productivity using indica japonica hybrids. Eight parents viz; SKUA 500, SKUA 538, SKUA 536-2, HPR 3106, HPR 2143, Bhrigudhan, Naggardhan and Varundhan were crossed following Griffing’s method 2, model I in a half diallel fashion. Experimental material comprising of eight rice parents and twenty-eight hybrids were evaluated in RBD with three replications during kharif 2021 and 2022 at Rice and Wheat Research Centre, Malan and for the cold tolerance in rabi 2020-21at the experimental farm of the Department of Vegetable Science and Floriculture, CSK HPKV, Palampur. Under cold conditions spikelet fertility was observed in the order of japonica x japonica lines > japonica x wide compatible lines > indica x japonica lines > indica x wide compatible lines > indica x indica lines.The analysis of variance revealed significant differences among the genotypes for all the traits studied in all the environments, suggesting prevalence of wide range of genetic variability. Genotype x Environment (G × E) interaction was significant for most of the traits except days to 75% maturity, plant height, flag leaf length, flag leaf width, spikelet fertility, length:breadth ratio and amylose content indicating a definite role of environment on the performance of genotypes. SCA variances were higher than the GCA Variances and average degree of dominance was more than unity, thus showing preponderance of non-additive gene action for all the traits except amylose content. Based on GCA effects, SKUA 500, HPR 2143 and HPR 3106 were the most promising general combiners for grain yield/plant and most of the yield components. On the basis of SCA effect and heterosis, the cross combinations SKUA 500 x Naggardhan, SKUA 536-2 x HPR 2143, HPR 2143 x Bhrigudhan, SKUA 536-2 x Naggardhan and HPR 2143 x Varundhan were found best in pooled environment. Positive correlation of grains/panicle, grain length, and harvest index with grain yield/plant in parents and hybrids along with positive direct effect in path analysis revealed importance of these traits for selection of high yielding genotypes.
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    ThesisItemOpen Access
    Studies on induced genetic variation for yield, disease resistance and quality traits in hard and soft wheat (Triticum aestivum L.)
    (CSK HPKV, Palampur, 2022-12-24) Sharma, Rohit Kumar; Rana, Vijay
    Present study was undertaken with the objectives to assess the efficacy of physical mutagens, chemical mutagens and their combinations and to estimate induced genetic variation and identify putative mutants for yield, yellow rust, powdery mildew resistance and quality traits. Experiment was conducted at the Rice and Wheat Research Centre, Malan during Rabi 2021-22. Experimental material comprised of two promising cultivars of bread wheat [Triticum aestivum (L.)] viz. HPW 89 (soft) and HPW 251 (hard). Experimental materials also included a total of ninety M2 mutant lines of wheat varieties HPW 251 and HPW 89. For working out mutagenic effectiveness and efficiency, both wheat varieties were subjected to mutagenesis by using EMS (0.3%, 0.6% and 0.9%), gamma-rays (250 Gy, 300 Gy and 350 Gy) and their combinations. HPW 89 exhibited higher reduction in germination percentage under lab conditions in comparison to HPW 251 across all the mutagen doses and their combinations. For shoot length, HPW 251 showed more reduction as compared to HPW 89 at lower dose. It may be attributed to the difference in shoot length of the parent (control) varieties. In both wheat varieties, root: shoot ratio decreased when the concentrations of gamma rays, EMS and their combinations increased. In case of EMS and gamma rays, HPW 251 exhibited more reduction in SVI (seedling vigour index). However, in combination HPW 89 showed the highest reduction in SVI. Under field conditions also more reduction in germination percentage was observed in HPW 89. HPW 251 have higher survival rates at the heading and maturity stages. Mutagenic frequency was found to be higher for the combination treatment 0.9% EMS +350Gy. Highest mutagenic effectiveness of EMS was observed at dose of 0.3% in both the varieties. The results regarding mutagenic efficiency in general showed a decline when the concentrations of gamma rays, EMS and their combinations increased. Analysis of variance revealed significant differences among wheat mutant lines for all the agro-morphological traits except tillers/ plant. High heritability coupled with high genetic advance was recorded for biological yield/plant, harvest index, peduncle length and flag leaf length. Days to 75% maturity, spike length, harvest index, grains/spike and 1000-grain weight showed significant positive correlation with grain yield/plant. Biological yield showed highest direct effect followed by harvest index. For grain hardness mutant Mt21 was found to be significantly superior than the best check, while other 10 mutant lines were statistically at par with this best check. Two mutants (Mt 62 and Mt63) were found to be yellow rust resistant,24 wheat mutants were found resistant to powdery mildew. One mutant line Mt23 was found to be superior for grain yield and grain hardness. Based on overall disease screening data Mt45, Mt53 and Mt87 were resistant to both powdery mildew and yellow rust. Preliminary findings on the differential response of soft and hard wheat lines to the mutagens and their combination treatments could be further studied by working out mutagenic effectiveness and efficiency on more parameters of biological damage. High yielding, disease resistant, hard grained and early flowering mutant progenies may further be subjected to rigorous evaluation by growing larger populations for isolation of superior mutants in M3.
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    ThesisItemOpen Access
    Genetic diversity analysis for agro-morphological traits and disease resistance under rainfed conditions in wheat (Triticum aestivum L.)
    (CSK HPKV, Palampur, 2022-12-17) Sharma, Priya; Rana, Vijay
    The present investigation entitled ‘Genetic diversity analysis for agro-morphological traits and disease resistance under rainfed conditions in wheat (Triticum aestivum L.)’ was conducted at Rice and Wheat Research Centre, Malan and the Molecular Cytogenetics & Tissue Culture Laboratory of the Department of Genetics and Plant Breeding, CSK HPKV, Palampur.The objectives were to assess the diversity amongst wheat genotypes using various agro morphological traits and molecular markers, and screening of genotypes for disease resistance at seedling (yellow rust and brown rust) and adult plant (yellow rust and powdery mildew) stage. The experimental material comprised of 36 wheat genotypes along with four checks viz., HPW 368 (Him Palam Gehun 2), HS 562, Agra Local and LWH (Local Wheat Hango) were evaluated for different agro-morphological traits in α-Randomized Block Design with three replications during rabi 2021-22. Sufficient genetic variability was observed for all the traits viz.,days to 50% flowering, flag leaf area, peduncle length, plant height, tillers per plant, grains per spike, 1000-grain weight, biological yield per plant, grain yield per plant and harvest index except days to 75% maturity, suggesting the scope of selection for these traits. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) along with high heritability and high genetic advance were observed for grain yield per plant and peduncle length, indicating that selection would be effective for these traits. Grain yield per plant showed significant and positive correlation with flag leaf area, tillers per plant, grains per spike, 1000-grain weight, biological yield per plant and harvest index. Also, biological yield per plant and harvest index were observed as the best selection indices for increasing grain yield owing to high direct and indirect effects of these traits in path analysis. Based on 11 agro-morphological characters, first four principal components revealed 73.96 % of total variability. D 2 analysis grouped genotypes into five clusters. The highest inter cluster distance was found between cluster II and V whereas the maximum contribution towards genetic divergence was made by 1000-grain weight. On the other hand, molecular markers analysis delineated the genotypes into three clusters. STRUCTURE divided the experimental lines into two major gene pools. On the basis of mean performance, five genotypes viz., HD 2967, TYRM 1, TYRM 2, SDN 37 and HPW 89 were found superior for grain yield per plant and related traits. Based on seedling resistance studies against predominant pathotypes of yellow rust (4) and brown rust (5), TYRM 2 and TYRM 3 expressed very high level of resistance, whereas PBW 677, Raj 4326, TAW 195, TYRM 1, TYRM 2, TYRM 3 and TYRM 4 appeared to be highly resistant for yellow rust and powdery mildew at adult plant stage. Conclusively, TYRM 2 and TYRM 3 were found to be highly resistant to yellow rust at both seedling and adult plant stage, and powdery mildew. These genotypes need further multilocation evaluation over the years or can be utilized in future hybridization programme.
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    ThesisItemOpen Access
    G × E interaction studies under different production systems in maize (Zea mays L.)
    (CSK HPKV, Palampur, 2022-12-26) Sood, Raghav; Katna, Gopal
    The present investigation was carried out for G × E interaction analysis of twelve maize genotypes for fourteen traits at six environments during kharif, 2021 and 2022 under two different production systems (Subhash Palekar Natural Farming and inorganic production system) using randomized block design with three replications. The pooled analysis of variance across environments exhibited significant mean squares due to environments and genotypes, whereas for G × E interaction all the traits except kernel rows per cob and ear circumference were found significant. G × E interaction and stability analysis following AMMI model also exhibited significant variation due to genotypes and environments for all the traits indicating presence of sufficient variability among the genotypes and environments, whereas G × E interaction was significant for all the traits except for number of kernel rows per cob and ear circumference (cm). The contribution of environment was greater than 50% for all the traits except number of kernel rows per cob, ear circumference (cm), 100-grain weight (g), harvest index (%) and protein (%). The mean squares for the IPCA 1, IPCA 2 and IPCA 3 cumulatively contributed more than 80% of the total G × E interaction for all the traits. AMMI stability index (ASI) and AMMI stability value (ASV) revealed that Girija was stable for maximum number of traits viz., days to 50% tasseling, days to 75% maturity, plant height (cm), cob height (cm), grain yield per plant (g) and 100-grain weight (g) across all six environments followed by L-315 which was stable for days to 50% silking, grain yield per plant (g), number of kernels per row, ear length (cm) and protein (%) and L-316 was stable for days to 50% tasseling, days to 75% maturity and harvest index (%) and also had highest mean grain yield per plant across all environments. AMMI biplots revealed that the environment Palampur under the inorganic production system was most favourable for number of kernels per row, ear length (cm), grain yield per plant (g) and 100-grain weight (g). Girija was most stable for grain yield per plant followed by L-315, L-316 and L-318 under inorganic production system. Bajaura Makka followed by L-315 and L-316 were stable genotypes under Subhash Palekar Natural Farming production system with high grain yield per plant. L-315 and L-316 were found suitable for cultivation under both production systems.
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    ThesisItemOpen Access
    Genetic assessment of mutagens induced variability for seed yield and component traits in soybean [Glycine max (L.) Merrill]
    (CSK HPKV, Palampur, 2022-12-18) Rana, Poonam; Kumari, Vedna
    The present investigation entitled “Genetic assessment of mutagens induced variability for seed yield and component traits in soybean (Glycine max (L.) Merrill)” was undertaken to estimate the extent of induced variations for seed yield and component traits and to identify potential mutants in soybean. The experimental material consisted of 35 M3 mutant lines of soybean parent variety Himso-1685 along with six checks viz., VLS 99, VLS-89, VLS-63, PS-1556, Hara Soya and Himso-1685 raised in randomized block design with three replications at the Experimental Farm of Department of Genetics and Plant Breeding, CSK HPKV, Palampur during kharif, 2021. Data were recorded for 14 morphological and yield components at appropriate stages of crop growth in soybean. Analysis of variance suggested the presence of sufficient genetic variability for seed yield and related traits which indicated the scope for the selection for all traits. The values of PCV were greater than the corresponding GCV values indicating the marked influence of environment in the expression of traits. High PCV along with high GCV values were obtained for harvest index whereas moderate values of PCV and GCV were obtained for plant height, pod insertion height, branches per plant, inter-node length, seeds per pods, pod length, 100-seed weight, biological yield per plant and seed yield per plant. Mean performance revealed that 12 mutants had higher seed yield per plant than the best check Himso-1685. None of the mutant lines were found to be significantly early in maturity than the best check VLS-99. High heritability along with high genetic advance was observed for inter-node length followed by 100-seed weight and harvest index indicating the predominance of additive gene action and additive × additive gene interaction in the inheritance of these characters. Hence, selection for these traits could be effective. Correlation analysis showed that seed yield per plant showed significant and positive association with days to 75% maturity, pod insertion height, branches per plant, nodes on main stem, inter-node length, pods per plant, seeds per pod, pod length, 100-seed weight and harvest index. On the other hand, plant height had significant and positive correlation with seed yield per plant at genotypic level. Hence, emphasis should be given on these traits for yield improvement in soybean. Path coefficient analysis revealed that the harvest index followed by biological yield per plant and nodes on main stem were found to be the best selection indices for soybean genetic improvement. Among 14 clusters, Cluster IV showed desirable mean values for plant height, pod insertion height, seed yield per plant and harvest index which suggested that the mutant lines P12(200Gy) and P4(300Gy) could be selected for these traits, cluster IX showed desirable mean values for nodes on main stem, inter-node length, seeds per pod and pod length which suggested that the mutant P4(100Gy) could be utilized for increasing seed yield and gene for earliness could be introgressed from the genotypes falling in cluster II. Out of 14 principal components (PCs), only five PCs exhibited more than 1.00 eigen value and showed about 74.63% variability. Six mutant lines viz., P4(100Gy), P13(100Gy), P12(200Gy), P7(300Gy), P4(0.5%) and P7(300Gy+1%) performed better for seed yield and component traits and exhibited highly resistant to resistant reaction against frogeye spot, pod blight, brown spot and bacterial pustules diseases. The promising mutants could be directly released as varieties after gene fixation or utilized in hybridization program in order to develop high yielding mutants coupled with earliness and disease resistance.