Upland Cotton Genotypes Research Articles

Genetic Dissection of Flowering and Plant Architectural Traits to Develop Early Maturing Compact Upland Cotton Genotypes for High-Density Planting

Genetic Dissection of Flowering and Plant Architectural Traits to Develop Early Maturing Compact Upland Cotton Genotypes for High-Density Planting

INTERRELATION OF YIELD AND ITS COMPONENTS IN COTTON (Gossypium hirsutum L.) GENOTYPES

Cotton is regarded as a profitable crop that gives people fiber and shelter. Research focuses on how yield, its components, and related attributes work together to enhance cotton. During the Kharif season of 2022, the present study was completed, implementing a randomized complete block design with ten genotypes and three replications. The study took place at the Nuclear Institute of Agriculture (NIA), located in Tandojam. This work aimed to examine the correlation and regression between upland cotton genotypes and heritability estimates for traits associated with yield. The outcomes showed that all of the parameters in the mean square of the ANOVA were significant. In contrast to the remaining genotypes, genotype FH-142 displayed the most favorable performance; it had the tallest plants, more sympodial branches, more bolls per plant, an improved seed index, and the longest staple length. The genotype CRIS-342 came in second, exhibiting good plant height, sympodial branches, a good number of bolls per plant, a ginning outturn, and the highest boll weight among the other genotypes. The findings of the correlation and regression indicated that the number of bolls per plant-1 had a highly significant and positive relationship with monopodial branches plant-1 (r = 0.73*) and (b = 2.45) and that the number of bolls per plant had a strong relationship with seed cotton yield plant-1 (r = 0.83**) and (b = 3.29). Staple length and seed cotton yield plant-1 had a negative correlation (-0.77*) with regression (b = -4.58). The highest heritability estimates in the broad sense are for monopodial branch plants (84.61), ginning outturn% (97.03), bolls plant-1 (93.96), plant height (90.70), staple length (79.31), and seed index (71.42). However, the boll's weight showed a low heritability (23.71). Further breeding programs can utilize genotype FH-142 to increase the number of sympodial branches, increase the number of boll plants, and improve the staple length. Genotype CRIS-342 can be utilized for medium-stature plant height, boll weight, and better ginning outturn. However, genotype NIA-BT-40 can be utilized for short-strategy plants with the highest ginning output.

Integrative analyses of long and short-read RNA sequencing reveal the spliced isoform regulatory network of seedling growth dynamics in upland cotton.

The polyploid genome of cotton has significantly increased the transcript complexity. Recent advances in full-length transcript sequencing are now widely used to characterize the complete landscape of transcriptional events. Such studies in cotton can help us to explore the genetic mechanisms of the cotton seedling growth. Through long-read single-molecule RNA sequencing, this study compared the transcriptomes of three yield contrasting genotypes of upland cotton. Our analysis identified different numbers of spliced isoforms from 31,166, 28,716, and 28,713 genes in SJ48, Z98, and DT8 cotton genotypes, respectively, most of which were novel compared to previous cotton reference transcriptomes, and showed significant differences in the number of exon structures and coding sequence length due to intron retention. Quantification of isoform expression revealed significant differences in expression in the root and leaf of each genotype. An array of key isoform target genes showed protein kinase or phosphorylation functions, and their protein interaction network contained most of the circadian oscillator proteins. Spliced isoforms from the GIGANTEA (GI) protien were differentially regulated in each genotype and might be expected to regulate translational activities, including the sequence and function of target proteins. In addition, these spliced isoforms generate diurnal expression profiles in cotton leaves, which may alter the transcriptional regulatory network of seedling growth. Silencing of the novel spliced GI isoform Gh_A02G0645_N17 significantly affected biomass traits, contributed to variable growth, and increased transcription of the early flowering pathway gene ELF in cotton. Our high-throughput hybrid sequencing results will be useful to dissect functional differences among spliced isoforms in the polyploid cotton genome.

Evaluation of Cotton Cultivars and Breeding Lines for Tolerance to Monosodium Methanearsonate (MSMA) Under Field Conditions

Monosodium methanearsonate (MSMA) is an organic arsenical herbicide used to control weeds such as grasses and nutsedges in Upland cotton (Gossypium hirsutum) production. Transient crop injury, yield reduction, and maturity delays have been observed in commercial Upland cotton. It is unknown if genetic variation in MSMA tolerance in cotton exists. In this field study, seven replicated tests were conducted in the same field to compare MSMA tolerance among 212 commercial cotton cultivars and advanced breeding lines. The tests were sprayed over the top at the 4-true-leaf stage, and seedlings were assessed for crop injury severity on a scale of 0 (no injury) to 5 (death). Significant genotypic variation in MSMA tolerance was detected in three tests, and broad-sense heritability estimates for MSMA tolerance ranged from 0.476 to 0.846 with a mean of 0.712, indicating that most phenotypic variation in MSMA tolerance is heritable. Nine tested G. barbadense genotypes, including seven commercial Pima cultivars and two Sea-Island cotton lines, exhibited minimal crop injury with severity ratings of 0.40 to 0.83 (except for one cultivar with 1.33). Among the remaining 203 Upland cotton genotypes with crop injury ratings ranging from 0.90 to 3.67, five commercial transgenic cultivars and 38 public breeding lines exhibited various levels of MSMA tolerance. The results represent the first study in germplasm evaluation for MSMA tolerance and identify a set of tolerant cotton genotypes that can be selected in cotton production or used to develop new cultivars for commercial cotton production.

Exploitation of heterotic effects in F1 hybrids for promoting earliness, yield components, and fiber quality of upland cotton (Gossypium hirsutum L.) genotypes

Exploitation of heterotic effects in F1 hybrids for promoting earliness, yield components, and fiber quality of upland cotton (Gossypium hirsutum L.) genotypes

Unravelling the Complex Interactions among Yield Attributes in Upland Cotton (Gossypium hirsutum L.) through Principal Component Analysis

Present investigation was carried out with 34 upland cotton genotypes to assess the genetic divergence for seven yields and yield attributes through principal component analysis to identify the factors contributing to yield variability. The PCA showed that the first two principal components explained 59.89% of the total variation. PC1 components showed positive relationship with ginning percentage whereas PC2 showed positive relationship with plant height, bolls per plant and seed cotton yield. Hence, these characters will be given priority in future for upland cotton breeding programme. Cluster analysis using Ward’s method was performed with seven quantitative traits displayed that four clusters were formed in which largest contribution was shared by cluster I with a maximum of 15 genotypes followed by cluster II consists of 10 genotypes. Based on PCA scores and cluster mean values, the genotypes NH 702, NDLH 2051-3, NH 703, AKH 2013-2 and CPD 1951 were considered to be desirable for utilization in upland cotton improvement.

Genotype × Environment Interaction for Genotype Cotton Upland Gossypium hirsutum L.

A field experiment was conducted in the summer of 2022 at the Agricultural Research Station / Daquq site, using six upland cotton genotypes (Lachata, Coker 310, pack coat, Spiro, Montana, and IK259), three levels of potassium sulfate fertilizer (0, 100, and 200) kg.h-1, and two distances between the lines (40 and 60) cm, to study growth, yield, its components, and qualitative traits. We conclude that the genotype Spiro was stable in terms of the number of fruiting branches, while the genotype Coker 310 was more stable in terms of plant height and span length at 2.5%, and the genotypes IK259 were more stable in terms of the number of bolls per plant, the index lint, and the index of uniformity, and the two genotypes Lachata and Coker 310 in terms of boll weight. Cocker 310 and Spiro genotypes were more stable in seed cotton yield per plant and uniformity index, Spiro and Montana genotypes in ginning outturn, and Lachata and Spiro genotypes in seed index, while Lachata genotype was more stable in staple length at 50% and staple strength.

A Grafting Procedure for Gossypium hirsutum Based on In Vitro Grown Seedlings

Intervarietal grafting, and in some cases interspecific grafting, practiced mainly in horticultural crops has many practical applications. Grafting can also be a useful tool to perform basic physiological, biochemical, and molecular studies to better understand communication between shoot and root in a row crop, such as cotton. We have established a grafting protocol for upland cotton (Gossypium hirsutum L.) genotypes. Although less efficient, it can be used to create grafts between upland and Pima (G. barbadense) or Old-world cottons (G. arboreum or G. herbaceum). The procedure used 8-day-old seedlings grown in culture under sterile conditions to obtain the scion and rootstock. The scion consisted of the shoot apical meristem with a few leaf primordia, epicotyl, and a small portion of the hypocotyl with the cotyledons removed. The rootstock retained 2 to 3 cm of basal hypocotyl portion with the roots trimmed. Cleft grafts were assembled under aseptic conditions followed by their culture in vitro. Once established, as indicated by the healthy growth of three to four true leaves and roots, the grafts were moved to soil in small pots. After hardening the grafts on a laboratory bench for few weeks, they were transferred to larger pots and grown to maturity in a greenhouse to obtain seeds. The success rate using our protocol ranged from 90 to 100% for Coker 312 genotype and its derivative transgenic and gene edited lines. The method was also applicable to generate intervarietal and interspecific graft unions among various types of cotton plants.

Evaluation of Cotton Genotypes Through the Selection Index Technique

Eight upland cotton genotypes introduced from different origins (BA440, FLASH, EDESSA, SPERO, IK259, W888, MONTANA and CANDIA) in addition to the two local cultivars (Coker 310 and Lachata) were cultivated on April 22 and 23, 2022 in the Rahmaniyah region at levels (0, 1, 2, and 3 g/liter). l) of nano-chelated NPK 20-20-20 under drip irrigation conditions, and using a randomized complete block design with three replications, in order to evaluate it by creating multiple selection indices and to estimate the expected increase in seed cotton yield. The results of the analysis of variance for the studied traits (seed cotton yield, plant height, number of fruiting per plant, number of bolls per plant, average boll weight, seed index, and lint index) showed that the mean square of genotypes and levels of nano-fertilizer and their interaction was highly significant for all traits except seed index in case of nano-fertilizer levels. The selection index that included the two traits of plant height and number of bolls per plant was characterized by a high increase in efficiency compared to direct selection of the seed cotton yield, indicating the importance of selection by adopting the selection index for several traits. This selection index in the current study was considered the best due to its high efficiency, and by adopting it in evaluating the genotypes, it was found that the highest mean of the index was 7.689 for the CANDIA genotype, with a significant difference from most other genotypes, followed by the FLASH and BA440 genotypes. The sequence of local varieties adopted in the study (Coker 310 and Lachata) in terms of performance was 10 and 7, respectively. It appeared that six introduced genotypes were superior to the best local cultivars (Lachata), and all introduced genotypes were higher than the least performing local variety (Coker 310).

Development of High-Yielding Upland Cotton Genotypes with Reduced Regrowth after Defoliation Using a Combination of Molecular and Conventional Approaches.

Cotton is an economically important crop. However, the yield gain in cotton has stagnated over the years, probably due to its narrow genetic base. The introgression of beneficial variations through conventional and molecular approaches has helped broaden its genetic base to some extent. The growth habit of cotton is one of the crucial factors that determine crop maturation time, yield, and management. This study used 44 diverse upland cotton genotypes to develop high-yielding cotton germplasm with reduced regrowth after defoliation and early maturity by altering its growth habit from perennial to somewhat annual. We selected eight top-scoring genotypes based on the gene expression analysis of five floral induction and meristem identity genes (FT, SOC1, LFY, FUL, and AP1) and used them to make a total of 587 genetic crosses in 30 different combinations of these genotypes. High-performance progeny lines were selected based on the phenotypic data on plant height, flower and boll numbers per plant, boll opening date, floral clustering, and regrowth after defoliation as surrogates of annual growth habit, collected over four years (2019 to 2022). Of the selected lines, 8×5-B3, 8×5-B4, 9×5-C1, 8×9-E2, 8×9-E3, and 39×5-H1 showed early maturity, and 20×37-K1, 20×37-K2, and 20×37-D1 showed clustered flowering, reduced regrowth, high quality of fiber, and high lint yield. In 2022, 15 advanced lines (F8/F7) from seven cross combinations were selected and sent for an increase to a Costa Rica winter nursery to be used in advanced testing and for release as germplasm lines. In addition to these breeding lines, we developed molecular resources to breed for reduced regrowth after defoliation and improved yield by converting eight expression-trait-associated SNP markers we identified earlier into a user-friendly allele-specific PCR-based assay and tested them on eight parental genotypes and an F2 population.

Evaluation of Cotton Genotypes Through the Selection Index Technique

Eight upland cotton genotypes introduced from different origins (BA440, FLASH, EDESSA, SPERO, IK259, W888, MONTANA and CANDIA) in addition to the two local cultivars (Coker 310 and Lachata) were cultivated on April 22 and 23, 2022 in the Rahmaniyah region at levels (0, 1, 2, and 3 g/liter). l) of nano-chelated NPK 20-20-20 under drip irrigation conditions, and using a randomized complete block design with three replications, in order to evaluate it by creating multiple selection indices and to estimate the expected increase in seed cotton yield. The results of the analysis of variance for the studied traits (seed cotton yield, plant height, number of fruiting per plant, number of bolls per plant, average boll weight, seed index, and lint index) showed that the mean square of genotypes and levels of nano-fertilizer and their interaction was highly significant for all traits except seed index in case of nano-fertilizer levels. The selection index that included the two traits of plant height and number of bolls per plant was characterized by a high increase in efficiency compared to direct selection of the seed cotton yield, indicating the importance of selection by adopting the selection index for several traits. This selection index in the current study was considered the best due to its high efficiency, and by adopting it in evaluating the genotypes, it was found that the highest mean of the index was 7.689 for the CANDIA genotype, with a significant difference from most other genotypes, followed by the FLASH and BA440 genotypes. The sequence of local varieties adopted in the study (Coker 310 and Lachata) in terms of performance was 10 and 7, respectively. It appeared that six introduced genotypes were superior to the best local cultivars (Lachata), and all introduced genotypes were higher than the least performing local variety (Coker 310).

Transcriptomic analysis reveals the beneficial effects of salt priming on enhancing defense responses in upland cotton under successive salt stress.

Priming-mediated stress tolerance in plants stimulates defense mechanisms and enables plants to cope with future stresses. Seed priming has been proven effective for tolerance against abiotic stresses; however, underlying genetic mechanisms are still unknown. We aimed to assess upland cotton genotypes and their transcriptional behaviors under salt priming and successive induced salt stress. We pre-selected 16 genotypes based on previous studies and performed morpho-physiological characterization, from which we selected three genotypes, representing different tolerance levels, for transcriptomic analysis. We subjected these genotypes to four different treatments: salt priming (P0), salt priming with salinity dose at 3-true-leaf stage (PD), salinity dose at 3-true-leaf stage without salt priming (0D), and control (CK). Although the three genotypes displayed distinct expression patterns, we identified common differentially expressed genes (DEGs) under PD enriched in pathways related to transferase activity, terpene synthase activity, lipid biosynthesis, and regulation of acquired resistance, indicating the beneficial role of salt priming in enhancing salt stress resistance. Moreover, the number of unique DEGs associated with G. hirsutum purpurascens was significantly higher compared to other genotypes. Coexpression network analysis identified 16 hub genes involved in cell wall biogenesis, glucan metabolic processes, and ribosomal RNA binding. Functional characterization of XTH6 (XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE) using virus-induced gene silencing revealed that suppressing its expression improves plant growth under salt stress. Overall, findings provide insights into the regulation of candidate genes in response to salt stress and the beneficial effects of salt priming on enhancing defense responses in upland cotton.

Determination of Genetic Diversity of Some Upland and Sea Island Cotton Genotypes Using High-Resolution Capillary Electrophoresis Gel

Cotton is a major source of natural fibre for the global textile industry and is also an important oilseed crop. Cotton fibre is the main source of textiles, the seeds are used for oil and the remaining bagasse is used as high-protein animal feed. In addition, cotton’s so-called short fibre is used in more than 50 industries. Cotton breeding is generally based on crossing the best yielding and fibre quality genotypes. However, cotton breeding programmes are negatively affected by the narrow genetic diversity of varieties. It is for this reason that the identification of genetic resources and the disclosure of genetic diversity are so important. Here, the genetic diversity of G. hirsutum and G. barbadense genotypes was determined using high-resolution capillary gel electrophoresis. Using 19 EST-SSR markers, a total of 47 genotypes were screened. The PIC values of the markers used ranged from 0.268 to 0.889. The mean PIC value was calculated to be 0.603. In terms of clustering, PCoA and population structure analyses gave similar results, and the genotypes could be divided into three main groups. Genetic admixture with G. hirsutum was found in some genotypes of the G. barbadense species. We can conclude that (i) the EST-SSR markers used in this study are effective in the determination of genetic diversity, (ii) the genetic diversity should be increased through the collection of genetic resources and (iii) the genetic EST-SSR markers in this study should be considered in breeding programmes by using them in QTL studies.

Comparative transcriptional and co-expression network analysis of two upland cotton accessions with extreme phenotypic differences reveals molecular mechanisms of fiber development.

Upland cotton (Gossypium hirsutum) is the main source of natural fiber in the global textile industry, and thus its fiber quality and yield are important parameters. In this study, comparative transcriptomics was used to analyze differentially expressed genes (DEGs) due to its ability to effectively screen candidate genes during the developmental stages of cotton fiber. However, research using this method is limited, particularly on fiber development. The aim of this study was to uncover the molecular mechanisms underlying the whole period of fiber development and the differences in transcriptional levels. Comparative transcriptomes are used to analyze transcriptome data and to screen for differentially expressed genes. STEM and WGCNA were used to screen for key genes involved in fiber development. qRT-PCR was performed to verify gene expression of selected DEGs and hub genes. Two accessions of upland cotton with extreme phenotypic differences, namely EZ60 and ZR014121, were used to carry out RNA sequencing (RNA-seq) on fiber samples from different fiber development stages. The results identified 704, 376, 141, 269, 761, and 586 genes that were upregulated, and 1,052, 476, 355, 259, 702, and 847 genes that were downregulated at 0, 5, 10, 15, 20, and 25 days post anthesis, respectively. Similar expression patterns of DEGs were monitored using short time-series expression miner (STEM) analysis, and associated pathways of DEGs within profiles were investigated. In addition, weighted gene co-expression network analysis (WGCNA) identified five key modules in fiber development and screened 20 hub genes involved in the development of fibers. Through the annotation of the genes, it was found that the excessive expression of resistance-related genes in the early fiber development stages affects the fiber yield, whereas the sustained expression of cell elongation-related genes is critical for long fibers. This study provides new information that can be used to improve fibers in newly developed upland cotton genotypes.

Effect of NaCl on Morphophysiological and Biochemical Responses in Gossypium hirsutum L.

Soil salinity is increasing due to several factors such as climate change and areas with uneven rainfall. This increase in level of salinity compelled the cotton breeders to develop a new germplasm that exhibit the suitable for salty soil. This study aimed to determine the salt tolerance of 50 accessions of Gossypium hirsutum in hydroponic conditions having three levels of NaCl, i.e., 0 mM, 150 mM, and 200 mM. The experiment was carried out in a completely randomized design with a factorial arrangement. Morphological, physiological, and biochemical attributes were estimated in these genotypes. The Na+/K+ ratio was determined by dry digestion method. Salt-susceptible and -tolerant genotypes were identified by biplot and cluster analysis. The genotypes showed significant differences for morphophysiological and biochemical parameters. In control, Cyto-515 showed enhanced growth with shoot length (30.20 cm), root length (20.63 cm), fresh shoot weight (2.34 g), and fresh root weight (0.93 g), while under 150 mM and 200 mM salinity levels, MNH-992 had the maximum root length (15.67 cm) and shoot length (24.67 cm). At a 150 mM salinity level, maximum levels of antioxidants were found in Kehkshan and CIM-595, while at a 200 mM salinity level, AA-703, CIM-595, and Kehkshan showed maximum values of antioxidants. The highest Na+/K+ ratio was observed in VH-363 and FH-114, while Kehkshan had lowest Na+/K+ ratio. The biplot analysis revealed that Kehkshan, CIM-595, VH-330, Cyto-178, MNH-992, and Cyto-515 were widely dispersed and distant from the origin, and exhibiting variability for morphophysiological and biochemical traits under the salt stress. In terms of performance across the treatments, accessions MNH-992, Kehkshan, Cyto-515, and CIM-595 performed significantly better. Peroxidase activity, proline contents, H2O2 determination, and Na+/K+ ratio were shown to be useful for the salt tolerance selection criteria. The potential of such salt tolerant accessions (MNH-992, Kehkshan, Cyto-515, and CIM-595) could be assessed after planting in salt affected areas and could be used in breeding programs for the development of diverse salt tolerant new genotypes of upland cotton.

Determination of protein and fatty acid composition of shell-intact upland cottonseed using near-infrared reflectance spectroscopy

Upland cotton is a leading natural fiber crop; and an important source of vegetable oil and protein. The protein content and fatty acid composition are important nutritional indicators of cottonseed. In order to establish rapid, high throughout, nondestructive and low-cost method for cottonseed nutrition evaluation, phenotypic data of seed kernel protein, oil and fatty acid content were combined with preprocessed near-infrared spectra of shell-intact cottonseed from 179 upland cotton genotypes to establish calibration models for these cottonseed nutrients. A total of 17 kinds of fatty acids were stably detected and quantitatively determined using Gas Chromatography-Mass Spectrometry (GC-MS) technology, including 7 kinds of fatty acids which were detected in cottonseed, to the best of our knowledge, for the first time. Finally, 19 NIR calibration models were established through partial least squares regression analysis, and evaluated by cross-validation and external verification. Results indicated that 16 models for seed protein, oil, and 14 fatty acids (capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, linoleic acid, arachidic acid, cis-11-eicosenoic acid, linolenic acid, heneicosanoic acid, docosanoic acid, tridecanoic acid, and lignoceric acid) achieved acceptable or satisfactory prediction ability. Three calibration models for palmitoleic acid, stearic acid and oleic acid obtained moderate prediction ability with R2cal above 0.7 which could be used in rough screening. Nine fatty acids in cottonseed were modeled for the first time. These results broadened our understanding of the fatty acid profile of cottonseed oil and laid a foundation for fast, nondestructive evaluation of cottonseed nutrient quality for cotton breeding, processing and marketing.

Impact of heat stress on agro-morphological, physio-chemical and fiber related paramters in upland cotton (Gossypium hirsutum L.) genotypes

The unpredictably changing climatic conditions, especially high temperatures, are putting a continuous threat to sustainable cotton production. The current study was designed to investigate the impact of heat stress on several morpho-physiological, biochemical, and fibre quality-related traits. The results revealed the presence of significant variations in agro-morphological, physio-chemical and staple length-related parameters for upland cotton genotypes and stress treatments. Further analysis of pooled data unveiled that heat stress had a detrimental impact on all studied plant traits. Severe reduction in plant height, nodes per plant, sympodial branches per plant, number of bolls per plant, ginning out-turn, and staple length were recorded under heat stress. A significant reduction in net photosynthetic rate (Pn) up to 28.6 % was observed in cotton genotype BH-200 (24.7 to 19.2 µmole m−2 s−1). The accumulation of hydrogen peroxide (H2O2) was increased from 7.1 % in BH-306 to 28.7 % in BH-200 under heat stress due to the incidence of oxidative stress. A substantial increase in the accumulation of antioxidants i.e., catalase (65 %–74 %), peroxidase (54 %–169 %), and superoxide dismutase (52 %–98 %) was seen under high-temperature stress conditions. The correlation coefficient analysis unveiled a significantly positive correlation of seed cotton yield with nodes per plant (r = 0.432*), net photosynthetic rate (r = 0.829**), peroxidase (r = 0.974**), and superoxide dismutase (r = 0.868**), under heat stress conditions. However, a negative but statistically significant correlation of seed cotton yield with ginning out turn (r = −0.466*), staple length (r = −0.898**), hydrogen peroxide (r = −0.955**) and catalase (r = −0.904**) was also observed. The overall results unveiled that cotton genotype BH-232 has a comparatively higher heat tolerance than other contesting genotypes while BH-306 showed the highest susceptibility to heat stress. Hence, BH-232 could be recommended after its approval for general cultivation in heat-prone areas of Pakistan.

Genetic basis and principal component analysis in cotton (Gossypium hirsutum L.) grown under water deficit condition.

Cotton is considered as the main crop in the agricultural sector of Pakistan. Water deficiency in this region in recent years has reduced the chances of high yields of cotton. Selection and creation of high-yielding varieties of cotton, even in water deficit conditions, is one of urgent tasks of today. For this purpose, 40 diverse genotypes of upland cotton were screened in normal and water deficit conditions in triplicate arrangement under split plot in a randomized complete block design. All the genotypes showed significant difference under both water regimes. Ten upland cotton accessions were screened out as water deficit tolerant (VH-144, IUB-212, MNH-886, VH-295, IR-3701, AA-802, NIAB-111, NS-121, FH-113, and FH-142) and five as water deficit sensitive (IR-3, CIM-443, FH-1000, MNH-147, and S-12) based on seed cotton yield and stress susceptibility index. These tolerant and sensitive genotypes were crossed in line × tester mating design. For further evaluation of genetic material, the seed of 50 F1 crosses and their 15 parents were field planted under normal and water deficit conditions during next cotton growing season. Traits related to yield under the study showed significant variations among the accessions and their half sibs. The results of the principal component analysis (PCA) exhibited that total variation exhibited by factors 1 and factor 2 were 55.55 and 41.95%, respectively. PCA transformed the variables into three factors, and only two factors (F1 and F2) had eigenvalue > 1. The degree of dominance revealed that all parameters were highly influenced by non-additive gene action under both water regimes. Furthermore, the line VH-295 and tester CIM-443 had better yield performance under water deficit stress. The cross-combinations, viz., VH-144 × S-12, NIAB-111 × IR-3, and VH-295 × MNH-147, were the best for yield contributing traits. These combinations may be helpful for germplasm enhancement on large scale under water scarcity. All the studied traits have non-additive types of gene action suggesting the usage of these genotypes in cotton hybrid development program against water deficit tolerance.

An Overview on Colour Cotton Research – A Review

In the current review of literature study we aimed to describe and delineate on current and future perspectives on colour cotton research. In India, about 40 coloured genotypes of upland cotton (G. hirsutum), mostly of various shades of brown and green colour have been developed. Brown cotton lines are at the forefront and expects that one of its varieties, DDCC-1, was proposed for release in 2021. Furthermore, DMB-225, a medium brown variety was developed in 2013, along with three other varieties. However, DMB-225 was not released commercially on the grounds that it would contaminate white cotton, though its fiber quality was found highly suitable. By not using chemical dyes, as well as reducing the use of pesticides, the naturally colored cottons have become popular for being ecological and environmentally safe. However, The limitations which impede commercial cultivation of coloured cotton itself signalize future thrust area of research viz. (i) development of wide range of colors with different shades, uniformity and stability, (ii) improvement of fiber properties such as length, strength and maturity, (iii) development of high yielding, early maturing varieties and hybrids, (iv) development of coloured cotton varieties and hybrids amenable to mechanical picking, (v) development of male sterility based hybrids in desi and upland coloured cottons, and (vi) development of coloured transgenic cottons..

Evaluation of Variation and Identification of Effective Traits on Seed Cotton Yield in Iranian Upland Cotton Genotypes (Gossipium hirsutum L.)

Evaluation of Variation and Identification of Effective Traits on Seed Cotton Yield in Iranian Upland Cotton Genotypes (Gossipium hirsutum L.)