Journal of Genetics and Applied Biotechnology
The Journal of Genetics and Applied Biotechnology (JGAB) is a multidisciplinary, peer-reviewed open-access journal dedicated to publishing high-quality research in genetics, molecular biology, and biotechnology. JGAB provides a global platform for researchers, academicians, and practitioners to share innovations that advance agriculture, medicine, industry, and environmental sciences.
Moisture-level dependent trait profile of drought response in Gossypium hirsutum
Section: Original Research Keywords: cotton, Drought, excised leaf water loss, relative water content, peroxidase, hydrogen peroxide Drought is one of the major abiotic stresses limiting cotton productivity, particularly in arid and semi-arid regions. The screening at the seedling stage has been extensively utilized to accelerate the process of selection, but the role of growth, water status, and oxidative traits can change with moisture conditions. Understanding this dependence on moisture-level is essential for trait-based phenotyping and drought-resilient breeding. A greenhouse study was conducted using forty upland cotton accessions grown under 100%, 75%, and 50% field capacity in a two-replications factorial completely randomized design. After two weeks of sowing, stress was imposed, and measurements were recorded at 45 days. Analysis of variance, regime-specific trait summaries, principal component analysis, and K-means clustering were used to interpret the dataset. Drought had decreased the shoot length and relative water content and changed the covariance pattern among traits. ANOVA revealed that genotypes, moisture treatment, and the interaction of genotype and treatment had significant effects on all traits. Multivariate analysis revealed a trait architecture shift as moisture decreased. ELWL and RL were observed to play a major role in principal component structure under normal water conditions, whereas POD and H2O2 had a dominant role under moderate and severe drought. Cluster centroids further distinguish between profiles related to higher antioxidant activity. The findings revealed that cotton seedlings are moisture-level specific instead of being determined by a hierarchical set of traits under drought stress. This study can be useful for selecting drought screening traits in cotton.
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Alternaria leafspot of cotton in northern Argentina: disease progress, cultivar resistance and fungicide effects under subtropical field conditions
Section: Original Research Keywords: Alternaria leaf spot of cotton, cotton cultivar resistance, pyraclostrobin–epoxiconazole, Argentine cultivars Alternaria leaf spot of cotton is a widespread foliar disease worldwide; however, information regarding disease progress and cultivar response under field conditions in northern Argentina is limited. This study aimed to evaluate disease progress, commercial cultivar performance, and the effects of fungicide application on plant growth, yield, and fiber quality. Field experiments were conducted during two growing seasons (2021–22 and 2022–23) in Reconquista, Santa Fe, Argentina, using three commercial upland cotton cultivars grown under fungicide-treated and untreated conditions, under high plant density and narrow row system. A commercial mixture of pyraclostrobin and epoxiconazole was applied at 50, 70, and 100 days after sowing. Disease incidence and severity were assessed over time, and plant growth, yield, and fiber quality traits were evaluated. Disease showed clear temporal progression in both growing seasons, reaching 100% incidence at 110 days after sowing, however, mean severity values remained moderate (<10%). The fungicide neither reduced incidence or severity nor improved yield or fiber quality. However, fungicide-treated plots showed significantly higher aboveground biomass, nearly 20% over control, suggesting a physiological effect unrelated to disease suppression, which warrant further research. Despite low disease pressure, cultivars differed in their response to infection, with NuOpal showing the highest susceptibility and Guazuncho 4 the lowest disease accumulation. Alternaria leaf spot of cotton progresses in northern Argentina even under unfavorable environmental conditions for fungal epidemics. Significant and consistent differences among cultivars were detected across seasons. Under low disease pressure observed in both seasons evaluated, fungicide applications did not significantly affect disease severity, yield or fiber quality.
Alternaria leaf spot of cotton, cotton cultivar resistance, pyraclostrobin–epoxiconazole, Argentine cultivars
Identification of candidate genes and transcripts through in silico analysis of DNA markers
Section: Original Research Keywords: cotton, bioinformatics, SSR markers, in silico PCR, candidate genes, fiber quality, abiotic stress. This article presents the results of determining candidate genes using in silico PCR using certain microsatellite DNA markers genetically linked to the genome of G. hirsutum L. and economically valuable traits. In this study, a virtual analysis of the region (100 kbp) around polymorphic microsatellite markers was performed using the NCBI database, UniPro Ugene, AUGUSTUS, and BLAST software. As a result, 29 valuable candidate genes and proteins were identified during the blast analysis of 10 SSR DNA markers related to fiber quality and salt resistance. The functions of the identified candidate genes and proteins were highlighted based on the interpretation of research results by foreign scientists. These results serve as an important basis for increasing the efficiency of marker-based selection (MAS) in cotton breeding and creating stress-resistant varieties.
cotton, bioinformatics, SSR markers, in silico PCR, candidate genes, fiber quality, abiotic stress.
Chromosome Pairing Behaviour in Intra- and Inter-specific Hybrids of Tetraploid Cotton (Gossypium spp.)
Section: Original Research Keywords: cotton, cytogenetics, meiosis, chromosome pairing, bivalents, hybrids Cotton (Gossypium spp.) is one of the most important fiber crops worldwide. However, its productivity and stability are increasingly constrained by climate-related factors such as drought, salinity, high temperatures, and the rising impact of pests. Although conventional breeding methods are effective for improving yield and fiber quality, their precision and efficiency remain limited when addressing polygenic traits and complex stress tolerance. This study presents the results of cytogenetic investigations conducted on intraspecific and interspecific F1 hybrids of tetraploid cotton species (Gossypium hirsutum L. and Gossypium barbadense L.). The analysis focused on the chromosome pairing in pollen mother cells at the metaphase I stage of meiosis. The results showed that in some intraspecific hybrids, normal chromosome pairing with 26 bivalents was observed, indicating cytogenetic uniformity. In contrast, some intraspecific hybrids exhibited considerable frequencies of univalents and quadrivalents. The highest mean number of univalents was recorded in ssp. punctatum var. gambia × ssp. punctatum (10.70±0.51) and ssp. punctatum var. gambia × ssp. mexicanum var. microcarpum palmerii (9.36±0.43). Quadrivalents were observed at low frequencies in ssp. punctatum var. florida × ssp. punctatum var. hopi (0.21±0.11) and ssp. glabrum var. mari galante × ssp. punctatum (0.14±0.10). These cytogenetic abnormalities suggest the presence of structural chromosomal differences and partial de-synapsis. In interspecific hybrids, univalents (0.12-0.28) and quadrivalents (0.11 ± 0.07) were detected at low frequencies, indicating the presence of karyotypic heterogeneity. However, the formation of 26 bivalents in the majority of hybrids confirmed their high level of phylogenetic relatedness. The obtained results are important for understanding the evolutionary and systematic relationships between G. hirsutum and G. barbadense, and provide a scientific basis for the targeted use of genetic resources in cotton breeding programs.
cotton, cytogenetics, meiosis, chromosome pairing, bivalents, hybrids
Genetic variability, heritability, and multivariate analysis of drought tolerance-related traits in field pea (Pisum sativum L.) under varying drought stresses
Section: Original Research Keywords: Peas, Drought Stress, Drought Tolerance, Abiotic stress Field peas (Pisum sativum L.) withstand short-term drought stress; however, prolonged water deficiency causes a significant reduction in grain yield, reported up to 25%. Drought tolerance is a complex mechanism involving the morphological, physiological, molecular, and cellular mechanisms. This study aimed to quantify genetic variability and identify key physiological traits governing drought tolerance in field pea under contrasting water stresses. Thirty-six pea genotypes were utilized to determine the inheritance of drought tolerance using a completely randomized design (CRD). Key traits evaluated include plant height, leaf area, days to fifty percent flowering, root length, shoot to root ratio, chlorophyll content, electrolyte leakage, relative water content, and proline accumulation. Highly significant differences (P ≤ 0.01) were observed for all traits, indicating substantial genetic variability. Plant height, root length, relative water content, and chlorophyll content exhibited high GCV, heritability, and genetic advance, indicating strong additive gene action and suitability for selection. Under drought stress, physiological traits including relative water content, leaf area, and chlorophyll content remained key contributors to variability, as confirmed by principal component analysis. Findings revealed a strong positive correlation among root length, leaf area, and relative water content, highlighting their collective role in drought tolerance. In contrast, yield per plant showed weak and inconsistent correlations under stress, suggesting its complex inheritance and dependence on multiple interacting traits. This weak association of yield with individual traits under severe stress suggests that indirect selection through key physiological traits may be more effective for improving productivity under drought conditions. Traits such as root length, relative water content, and chlorophyll content can be effectively used for selecting drought-tolerant genotypes.
Plant defense activator-mediated seed priming suppresses leaf rust (Puccinia triticina) and enhances yield in bread wheat genotypes
Section: Original Research Keywords: Bread wheat; leaf rust; seed priming; dose optimization; response-dependent on genotype. Puccinia triticina causing leaf rust is a significant pathogen of wheat because it negatively affects the canopy functioning, grain filling, and final yield. This research investigated the impact of seed priming on leaf rust severity, growth and yield of three bread wheat varieties Arooj-22, Dilkash-20 and MH-21. For this experiment, a completely randomized factorial design was used with three replications, including hormonal (jasmonic acid, salicylic acid, gibberellic acid), nutritional (KNO₃), botanical (moringa leaf extract), and biological (Trichoderma sp.) priming treatments. Disease severity and agronomic traits were significantly influenced by seed priming, with treatment and varietal differences in response. Arooj-22 was lowest in severity with GA 25 ppm and Dilkash-20 with Trichoderma 50 %, but the highest severity was in diseased control, especially in MH-21. Arooj-22 had the greatest yield of plants in Trichoderma 50 % and KNO3 0.5 % had the best yield response uniformly in all three varieties. Correlation analysis demonstrated that 1000 grains weight, leaf area and plant yield had a negative relationship with disease severity, but multivariate analysis differentiated between favorable lower dose treatments and weaker higher dose treatments. In general, the results indicate that seed priming has the potential to lessen the severity of leaf rust and significantly enhance the productivity of wheat, although its effectiveness requires attention to the choice of the primer, dose, and host genotype in the field pot condition.
Bread wheat; leaf rust; seed priming; dose optimization; response-dependent on genotype.
Multivariate analysis for the development of an ideotype of ornamental sunflower (Helianthus annuus L.) in the autumn season
Section: Original Research Keywords: Ornamental sunflower, autumn ideotype, multivariate analysis, genetic diversity, cluster analysis, principal component analysis The development ideotype ornamental sunflower (Helianthus annuus L.) in autumn has a strategic value because few flowers are available in autumn. This study was conducted to assess the genetic diversity and elite lines that perform better in the autumn season. To fill this gap, 28 multi-headed genotypes that are genetically different were evaluated under semi-controlled conditions of pot culture in a completely randomized design (CRD) with three replications at the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. Data were recorded on different parameters such as: Plant height, Stem diameter, Head diameter, Number of heads per plant, Number of leaves and leaf width. Analysis of variance (ANOVA) revealed highly significant variation for all the recoded traits, which substantially shows that there is high genetic variability in the germplasm. Correlation analysis revealed that vegetative traits were strongly and positively correlated with each other, whereas head diameter demonstrated negative correlations with most parameters, which provided evidence of a resource allocation trade-off between vegetative vigor and floral display. Principal component analysis accounted for 58.2 percent of overall variance in the first two components and hierarchical cluster analysis organized the genotypes into two separate phenotypic groups, with Cluster I having homogeneous ideotype-proximate materials and Cluster II having divergent genotypes that could be candidates to provide new combination of traits. The ornamental sunflower ideotype was a medium to small plant height, multiple heads per plant, medium to large diameter of the head, strong stem, and early flowering. Direct selection with genotypes similar to this ideotype is suggested, and divergent members of a cluster are to be utilized as parents in hybridization programs to obtain better ornamental sunflower varieties.
Ornamental sunflower, autumn ideotype, multivariate analysis, genetic diversity, cluster analysis, principal component analysis
Combining Ability Analysis of Yield and Its Component Traits in Upland Cotton (Gossypium hirsutum L.) Using a Diallel Mating Design
Section: Original Research Keywords: Diallel Analysis, Dominant, Non-Additive, Combining Ability, Reciprocal Effects, Heterosis Cotton (Gossypium hirsutum L.) is a valuable fiber crop that is of great economic importance. The genetic basis of the yield-related traits was investigated in this study in a full diallel mating design that involved four parental genotypes (AGC-2, MNH-998, RH-647 and Super Gold) and their twelve F1 hybrids. Characteristics such as plant height, monopod and sym pod branches, bolls per plant, boll weight, lint percentage and seed cotton yield were considered. ANOVA indicated that there was a significant genetic variation across genotypes. The integration of the ability analysis revealed that not only general combining ability (GCA) but also specific combining ability (SCA) played a significant role with non-additive gene action dominating the majority of traits. Some crosses such as AGC-2 × RH-647, AGC-2 × MNH-998 and MNH-998 × RH-647 had high SCA effects and heterotic potential. The existence of important reciprocal effects (RE) indicated the importance of maternal influence. These results indicate that cross breeding and using heterosis is an effective method in enhancing cotton production and fiber-related characteristics.
Assessment of Induced Polyploidy in Watermelon (Citrullus lanatus L.)
Section: Original Research Keywords: Induced polyploidy, Chromosome doubling, Colchicine, Identification, Charaterization Watermelon (Citrullus lanatus L.), a diploid fruit crop with 2n=22 chromosomes, is valued for its sweetness and health benefits. Originating from South Africa, it belongs to the Cucurbitaceae family. Globally, annual production reaches about 117 million tons. Recently, seedless watermelons, derived from crossing tetraploid (4n=44) and diploid (2n=22) plants to produce triploid (3n=33) cultivars, have gained popularity over seeded types due to the inconvenience caused by seeds. In Pakistan, limited genetic studies on watermelon hinder breeding efforts. This research focused on developing methods to induce and identify polyploidy in watermelon using colchicine, an anti-mitotic agent, to produce tetraploids for seedless watermelon breeding. Two treatment methods were employed: seeds were soaked in colchicine solutions at 0.15% and 0.20% for 20 hours, and sprouts were soaked at the same concentrations for 30 minutes over two consecutive days. Results showed that colchicine treatments significantly affect plant growth. Treated plants had reduced height and leaf number but increased stem diameter. Leaves appeared darker, rougher, and thicker, with higher chlorophyll content correlating with the darker green color. The emergence of the first true leaf was delayed compared to controls. Pollen from treated plants had an increased diameter but decreased fertility. Additionally, stomatal length and width increased, while density decreased, indicating tetraploidy. An increase in the number of chloroplasts per guard cell was also observed. These morphological and anatomical changes confirm successful induction of polyploidy. Seed soaking with colchicine at 0.15% and 0.20% was particularly effective in developing tetraploid lines, which are valuable for seedless watermelon breeding programs.
Dissecting Key Yield Components in Soybean (Glycine max L.) Genotypes Through Multivariate Analysis
Section: Original Research Keywords: Soybean, genetic variation, Correlation Analysis, Path coefficient Analysis Soybean (Glycine max L. Merrill) is a highly valued leguminous oilseed crops and can contribute to meet the Pakistan’s edible oil demand and reduce import bill, However, limited availability of high yielding and environmental adapted soybean genotypes is a major hinderance for its adoption by local farmers. The current study was executed to determine variability and adaptability patterns of seventy exotic soybean accessions under agro-climatic conditions of Okara, Pakistan. An augmented block design with two commercial checks (NARC-21 and Faisal Soybean) was used to study ten yield related characteristics. Result exhibited a substantial amount of diversity in the studied germplasm. Genotypic correlation and path coefficient analysis revealed that seed per pod, pods per plant, pod length, pod width and hundred-seed weight were significant contributors to seed yield. Heritability and genetic advance estimates depicted the predominance of additive gene action in pods per plant, plant height and the hundred-weight of the seed. The genotypes Toano, Glenwood, Delsoy 4500, Lawrence and DSR-262 were identified as promising parental lines for use in future crop improvement programs.
Molecular Characterization of HSP20 and HSP40 Genes Governing Heat Stress Tolerance in Chili
Section: Original Research Keywords: genome wide analysis, hsp 40 genes, HSP20 genes, heat shock proteins, heat stress, capsicum annum Heat stress has a devastating effect on the growth and development of plants as well as on their productivity, it leads to proteins destabilization and cellular homeostasis. The mitigation of these effects depends on heat shock proteins (HSPs). This paper gives a global identification, characterization and expression profiling of Hsp20 and Hsp40 families of genes in chili (Capsicum annuum) to understand their functions in heat stress tolerance. There were 64 non-redundant HSP20 genes found, mostly localized in the cytoplasm, then the nucleus, chloroplast and membrane additional findings provided support the hypothesis that HSP20 has a significant role in cytoplasmic protein protection. The structure of genes showed tight folds having a limited number of introns, which allows swift transcriptional stimulation during heat stress. Promoter analysis revealed that there are five high-profile cis-acting elements with ARRIA and WRKY71OS among them, which lend evidence to the belief that stress- and hormone-responsive signals play a complex role in the process of transcription. Genome wide screening of the HSP40 genes provided several cytoplasmic members which when expressed during heat shock indicates that they are involved in the activation of protective molecular chaperone complexes and the maintenance of cellular proteostasis. Hsp20 and Hsp40 proteins were found to coordinate their functions efficiently in stabilization of proteins and aggregation inhibition and maintaining metabolic continuity in the face of thermal stress. Altogether, the results offer useful molecular understanding of the thermotolerance processes in chili and discover candidate genes to molecular breeding and genetic engineering in improving heat stress tolerance in crops.
Evaluation of Wheat Genotypes for Physiological and Yield Related Traits Under Rainfed Conditions
Section: Original Research Keywords: Wheat, Rainfed, Physiological parameters, Yield Wheat (Triticum aestivum L.) is staple food of more than two billion people across the world. Wheat farmer faces many constraints due to changing climatic conditions. About 50% yield losses occur due to inadequate rainfall in arid and semiarid region. Therefore, plant breeders have to evaluate and develop climate resilient wheat varieties to ensure food security. The prime objective of the study was to evaluate performance of spring wheat genotypes for various physiological and yield related traits under rainfed conditions. To achieve this objective, research was carried out at National Agricultural Research Centre (NARC) during the two consecutive Rabi seasons (2020-2021) and (2021-2022). The data was collected at different stages of crop for physiological traits viz. canopy temperature depression (CTD), spade chlorophyll content, relative water content, cell membrane stability, day to heading, day to maturity, yield related traits viz. plant height, Fertile tillers per plant, spike length, number of spikelets per spike, 1000 grain .weight, grain number per spike, yield per meter square. The data collected for all traits were subjected.to analysis of variance (ANOVA).and correlation to ascertain the significance of result. The present study revealed that wheat genotypes NR-448, 18696, AAS-11 and Pakistan 13 showed best performance for grain yield under rainfed conditions. The grain yield was positively correlated with all the yield related parameters.
Wheat, Rainfed, Physiological parameters, Yield
Climate Smart Cotton: Integrative Genomics, Breeding and Biotechnological Strategies for Sustainable Fiber Production.
Section: Review Article Keywords: Cotton, Climate-smart agriculture, Abiotic stress, Tolerance, Genomic Selection, Genome wide association studies, CRISPR-Cas, Molecular breeding Cotton (Gossypium spp.) is a significant fiber crop in the world but its productivity, as well as sustainability is being limited by climate-related pressure such as drought, salinity, heat, and increased pest pressure. Although traditional breeding has enhanced yield and fiber quality, the breeding process is not always precise and efficient to provide the ability to respond to complex and multigenic stress-adaptive traits. This review brings together recent innovations on cotton improvement by combining the use of genomic tool, the use of the concept of molecular breeding and the contemporary biotechnological tools. We show the advances in the study of the physiological and molecular pathways of abiotic stress tolerance, including osmotic regulation, ion homeostasis, and heat-shock responses. The discovery of traits and identification of functional alleles has been made faster by the developments of genome-wide association studies, quantitative trait locus mapping, and multi-omics platforms. Moreover, new technologies, such as CRISPR/Cas-based genome editing, RNA interference, genotype-independent systems of transformation, and genomic selection, are changing the breeding pipelines, that is, they enable the rapid and specific creation of multi-stress-resilient cultivars. The review focuses on integrative and data-driven breeding models with successful help of seed systems and international cooperation to deploy genomic innovation into climate-sensitive cotton varieties. Taken together, these developments make cotton improvement a systems science with the potential to maintain the productivity of fibers and financial sustainability amidst fluctuating climatic conditions.
Biochemical Strategies of Cotton Defense: Osmolyte Accumulation and Stability Enhance Resistance to Cotton Leaf Curl Virus
Section: Original Research Keywords: Cotton leaf curl virus (CLCuV); osmolytes; glycine betaine; proline. resistant genotypes; biochemical markers. Cotton leaf curl virus (CLCuV) remains a major constraint to sustainable cotton production, necessitating the identification of genotypes with superior tolerance mechanisms. This study evaluated the biochemical responses and disease severity of multiple cotton genotypes under graft inoculation. Substantial differences were observed between uninoculated and inoculated plants in the accumulation of glycine betaine (GB), proline (PRL), total soluble sugars (TSS), and total soluble proteins (TSP). Inoculated plants exhibited sharp increases in GB and PRL contents, with the highest levels recorded in FH-494, FH-492, FH-938, and FH-Super Cotton, indicating their critical role in osmotic adjustment. TSS showed moderate enhancement, particularly in FH-938 and FH-494, while TSP displayed a mixed trend, remaining relatively stable in tolerant lines but declining in sensitive ones. These biochemical adjustments were closely associated with disease severity indices (SI), which varied significantly among genotypes. Highly susceptible entries (e.g., FH-534, FH-933, FH-509, FH-5100, FH-415) recorded elevated SI values (>4.4), while tolerant lines (e.g., FH-525, FH-930, FH-520, FH-Anmol, FH-Super Cotton) showed intermediate responses. Notably, FH-492 and FH-494 exhibited the lowest SI (~1.6) alongside strong osmolyte accumulation and protein stability, identifying them as promising donor parents for resistance breeding. Overall, results underscore that enhanced GB and PRL accumulation, moderate sugar induction, and sustained protein integrity constitute a coordinated biochemical defense strategy against CLCuV. The integration of such resilient genotypes into breeding programs, supported by osmolyte-based biochemical screening, offers a practical approach to improving virus resistance and sustaining cotton productivity.
Cotton leaf curl virus (CLCuV); osmolytes; glycine betaine; proline. resistant genotypes; biochemical markers.
Evaluation of diversity and estimation of association among various yield related and fiber quality traits in Gossypium hirsutum L.
Section: Original Research Keywords: Correlation Analysis, Hierarchical clustering, multivariate, Morphological Traits Cotton is majorly grown for fiber in various regions of world. It has major role in Pakistan’s economy. Despite of its increased production within country, the demand of good quality and contamination free fibers is also increasing day by day. Moreover, cotton is also effected by various biotic and abiotic factors that result in low yield and reduced quality of cotton fibers. Various yield and fiber quality traits are associated with each other and can be improved simultaneously. Correlation coefficient analysis tells about the direction of relationship along with the extent of association among traits. Moreover, diversity among genotypes is also a crucial factor for effective selection of desired genotypes which can be assessed through cluster analysis. This research was performed under RCB design with three replications. 17 genotypes of upland cotton were utilized to estimate correlation coefficient between quantitative characters of G. hirsutum. 13 plant parameters including both morphological and fiber quality traits were observed for each accession. Analysis of variance exhibited significant variations among varieties for all the observed attributes at 5% level of significance. Results of correlation analysis demonstrated that sympodial branches, height of plants, number of bolls, average seeds per boll, 100 seed weight and fiber length had linear relation with each other. Positive correlation also existed among GOT and lint index, fiber strength and fineness. Meanwhile, number of monopodia and boll weight had negative relation with fruiting branches, average number of bolls, plant height, count of seeds per boll, 100 seed weight and fiber length. Cluster analysis revealed four clusters of genotypes with cluster III was the smallest one. Cluster I, II, III and IV comprised of 6, 4, 1, 6 genotypes, respectively. The objective of the research was to determine correlation among yield and fiber traits and identify diversity among genotypes.
Correlation analysis of several economic traits of upland cotton (Gossypium hirsutum L.)
Section: Original Research Keywords: seed cotton yield, Correlation Analysis, Hierarchical clustering Cotton is a leading natural source of textile fiber. It is highly susceptible to biotic & abiotic stresses, which decreases cotton production every year. The purpose of this research is to assess the correlation among yield related characters and fibre traits, that help in preliminary selection of desirable characters and genetically diverse parental line for future breeding of cotton. Eighteen varieties of upland cotton were cultivated in RCBD in three repetitions in fields of Plant Breeding and Genetics, University of Agriculture Faisalabad. Data was recorded for several agronomic traits of upland cotton. i.e. Bolls per plant, height of the plant, sympodial branches, seeds per boll, monopodial branches, 100 seed weight, boll weight, strength of fiber (g/tex), lint index, GOT (%), Seed cotton yield (g) and fiber fineness (µg /inch), fiber length (mm) Agglomerative hierarchical clustering was performed to group diverse genotypes into distinct clusters by using ward’s minimum variance method. Significant variation was observed among all genotypes through analysis of variance. Bolls/plant, weight of boll, sympodial branches and 100 seed weight revealed significantly positive relationship with seed cotton yield. It also revealed positive relationship with fibre fineness, However bolls per plant displayed strong negative correlation with fiber length. Traits exhibiting positive association to yield of seed cotton can be selected to be utilized in breeding programs for producing high yield cultivars. Eighteen varieties were classified into four groups. Cluster IIⅠ is the biggest cluster, which is sub divided into two sub-clusters i.e. Cluster IIⅠa & Cluster IIⅠb, which comprises of eight and two genotypes respectively followed by Cluster Ⅰ and Cluster IV comprised of 3 genotypes in each. However, Cluster II is the smallest cluster consisted of only two genotypes.
Optimization of LD50 and Induction of Mutation Through EMS in Dalbergia sissoo
Section: Original Research Keywords: Dalbergia sissoo; Mutagenesis; EMS; LD50; leaf morphology Dalbergia sissoo is an economically important tree of the Indian subcontinent. In this study, three ethyl methanesulfonate (EMS) concentrations with four exposure times were applied to identify the optimum combination for the induction of mutations. The lethal dose (LD) estimated using germination percentage was not a suitable criterion, as the survival percentages reduced drastically. The survival percentage after 30 days to estimate LD. Among the LD25, LD50, and LD75, the LD50 was identified as the optimal criterion for the survival of mutants. The LD50 was observed with two combinations of treatments: 0.48% EMS dose for 12 hours and 1.39% EMS dose for 6 hours. The progressive increase in EMS concentrations reduced the survival percentage, indicating residual toxicity. 0.48% MS for 12 hours and 1.39% EMS for 6 hours were used to develop a mutagenized population. Among the affected traits, height, stem morphology, leaf shapes and leaf size was. The chlorophyll content was negatively affected due to EMS; a decrease to 9.7 was observed compared to the control of 42.01. When the collected data were analyzed using analysis of variance significant differences were found among all the traits studied. A decrease in survival rate was also observed after six months and again after one year. The study would improve our understanding of EMS-induced mutagenesis and its use in tree plants.
Dalbergia sissoo; Mutagenesis; EMS; LD50; leaf morphology