Improve Fiber Quality Research Articles

Long-term assessments of cotton fiber quality in response to plant population density: Reconciling fiber quality and its temporal stability

Regulation of plant population density is crucial for optimizing cotton fiber quality. However, the relationship between plant density and fiber quality stability under contrasting climatic conditions remains unclear, and the compromise between fiber quality and temporal stability is unknown. In this study, based on a long-term field experiment with various plant densities (1.5–10.5 plants m–2) conducted from 2008 to 2021, cotton fiber quality variability, including fiber length, fiber strength, elongation, uniformity index, and micronaire, and their temporal stability, were evaluated. We determined the optimal plant density for cotton cultivation and elucidated the contributions of plant density and climatic conditions to the variability of cotton fiber quality and its temporal stability in China’s Yellow River Valley. The results revealed that cotton maintained its upper-intermediate quality throughout the study period, with fiber length, strength, elongation, uniformity index, and micronaire values ranging between 28.04 and 30.03 mm, 26.15–30.05 cN tex–1, 5.90–6.83%, 83.85–85.44%, and 4.24–5.14, respectively. An increase in plant density improved fiber quality but impaired temporal stability (P < 0.01), and slight increases in stability at lower plant densities resulted in substantially decreased probabilities of years with major declines in fiber quality class. Plant density and climatic conditions regulated the quality traits (23.5% and 69.3% of the explained variance, respectively), including fiber length, fiber strength, and micronaire, while climate was the most important factor (75.9% of the explained variance) in determining their temporal stability. Photosynthetically active radiation and maximum and mean temperature exhibited significant positive effects on fiber quality, whereas mean diurnal temperature range had the opposite effect. A plant density of 3.3–5.1 plants m–2 ensures the highest temporal stability of cotton fiber quality without declines in the fiber quality class. This study first provides insights into balancing cotton fiber quality and temporal stability through agronomic interventions, with implications for the quantitative prediction of future crop quality changes owing to climatic variation.

Genome scale analysis of 1-aminocyclopropane-1-carboxylate oxidase gene family in G. barbadense and its functions in cotton fiber development

A class of proteins, 1-aminocyclopropane-1-carboxylate oxidase (ACO), is required in the final step of production of ethylene from its immediate precursor 1-aminocyclopropane-1-carboxylic acid (ACC). Despite the crucial and regulatory role of ACO gene family in the fiber development, it has not been thoroughly analyzed and annotated in G. barbadense genome. In the present study, we have identified and characterized all isoforms of ACO gene family from genomes of Gossypium arboreum, G. barbadense, G. hirsutum and G. raimondii. Phylogenetic analysis classified all ACO proteins into six distinct groups on the basis of maximum likelihood. Gene locus analysis and circos plots indicated the distribution and relationship of these genes in cotton genomes. Transcriptional profiling of ACO isoforms in G. arboreum, G. barbadense and G. hirsutum fiber development exhibited the highest expression in G. barbadense during early fiber elongation. Moreover, the accumulation of ACC was found highest in developing fibers of G. barbadense in comparison with other cotton species. ACO expression and ACC accumulation correlated with the fiber length in cotton species. Addition of ACC to the ovule cultures of G. barbadense significantly increased fiber elongation while ethylene inhibitors hindered fiber elongation. These findings will be helpful in dissecting the role of ACOs in cotton fiber development and pave a way towards genetic manipulations for fiber quality improvement.

Delayed harvest time affects strength and color parameters in cotton fibers

AbstractCotton (Gossypium hirsutum L.) is the most widely used natural fiber worldwide in the textile industry; thus, maintaining or even improving fiber quality is essential to produce the best quality yarn and uniform fabrics. Final fiber quality properties are determined not only by genotypes or environmental conditions during crop development but can also be affected by other postmaturity factors, such as harvesting and ginning methods, and harvest time (HT). The aim of this study is to associate the different environmental factors that affect specific lint quality traits produced by a delay in HT, also assessing cultivar effect. This field study included four cotton cultivars evaluated at seven different HTs (manual harvested) for different quality parameters. Results indicate that prolonged exposure of cotton fiber to the environment affects lint percentage (LP), strength (Str), reflectance (Rd), and yellowness (+b). Str showed a decrease of 0.02 g tex−1 day−1 from defoliant application, whereas LP, Rd, and +b presented different rates according to the season. No differences were obtained neither for length nor for fineness and maturity (micronaire) traits. In addition, the analysis of the results together with the climatic data recorded during the experiments indicated a negative correlation among Str, Rd, and +b with the number of rainy days, accumulated precipitation, and frost temperatures. Overall, this study establishes specific relationships between certain fiber characteristics and environmental conditions, being an important tool for crop management with regards to climate predictions that could help to make estimates of economic losses when the harvest is delayed.

QTL Mapping for Fiber Quality Based on Introgression Lines Population from G. hirsutum × G. tomentosum

As one of the most widely cultivated cotton species in China, upland cotton has moderate fiber quality and wide applicability, but its genetic basis is relatively narrow. To expand genetic diversity and improve fiber quality, in this study an introgression population (BC5S5) containing 107 lines was constructed by using G. hirsutum acc. 4105 as the recurrent parent and G. tomentosum as the donor parent. Using the specific-locus amplified fragment sequencing (SLAF-seq) strategy, 3157 high-throughput single nucleotide polymorphism (SNP) markers were obtained. Linkage analysis showed that a total of ninety-one QTLs related to fiber quality traits were detected in three environments, and the phenotypic variance explained (PVE) rates were 4.53–20.92%. Forty-six QTL (50.55%) synergistic genes were derived from G. tomentosum. Among them, qFS-A02-1 and qSCI-A02-1 were stably detected with a PVE of 9.8–16.71% and 14.78–20.92%, respectively. Within the candidate interval, Ghir_A02G012730, Ghir_A02G012790 and Ghir_A02G012830 were found to be possibly involved in cellulose and cell wall biosynthesis, with a relatively high expression during fiber development, 20 DPA and 25 DPA, which suggested that these three genes may be involved in the regulation of fiber strength traits, but their functions need further validation to determine the regulatory mechanism. Our research lays the foundation of fiber quality related to basic genetic research and breeding in cotton.

Harvest Aids Applied at Appropriate Time Could Reduce the Damage to Cotton Yield and Fiber Quality

The application of harvest aids is an important prerequisite for the mechanical harvesting of cotton that can effectively reduce the impurity content and improve the picking rate and operating efficiency of machine-picked cotton. However, determining the appropriate spraying time of harvest aids to achieve the synergistic improvement of cotton boll weight and fiber quality is still unclear. In this study, the damage of harvest aids to cotton boll weight and fiber quality as well as its quantitative relationship to cotton boll age were studied through testing different harvest aid compounds and spraying times. The spraying of harvest aids significantly shortened the boll growth period of cotton by 3.60–6.45 d, and concentrated boll opening was beneficial to cotton mechanical harvesting. The boll weight of immature cotton was significantly decreased by 0.63–1.12 g; the fiber strength was significantly decreased by 2.48–2.77 cN·tex−1, and the micronaire value deteriorated. The negative effect on the boll weight and fiber quality was aggravated by the decrease in the ratio of boll age to boll period (Rd/b) during the harvest aid spraying time. When the fiber strength damage was controlled at 1%, the spraying time Rd/b of the harvest aids was 0.77–0.82, and the boll weight loss was also controlled at 5%. Therefore, it is recommended that an Rd/b of 0.77–0.82 be used to balance the contradiction between cotton yield and fiber quality under harvest aid application.

Overexpression of cotton Trihelix transcription factor GhGT-3b_A04 enhances resistance to Verticillium dahliae and affects plant growth in Arabidopsis thaliana

Verticillium wilt is a soil-borne fungal disease that severely affects cotton fiber yield and quality. Herein, a cotton Trihelix family gene, GhGT-3b_A04, was strongly induced by the fungal pathogen Verticillium dahliae. Overexpression of the gene in Arabidopsis thaliana enhanced the plant's resistance to Verticillium wilt but inhibited the growth of rosette leaves. In addition, the primary root length, root hair number, and root hair length increased in GhGT-3b_A04-overexpressing plants. The density and length of trichomes on the rosette leaves also increased. GhGT-3b_A04 localized to the nucleus, and transcriptome analysis revealed that it induced gene expression for salicylic acid synthesis and signal transduction and activated gene expression for disease resistance. The gene expression for auxin signal transduction and trichome development was reduced in GhGT-3b_A04-overexpressing plants. Our results highlight important regulatory genes for Verticillium wilt resistance and cotton fiber quality improvement. The identification of GhGT-3b_A04 and other important regulatory genes can provide crucial reference information for future research on transgenic cotton breeding.

Structural variation (SV)-based pan-genome and GWAS reveal the impacts of SVs on the speciation and diversification of allotetraploid cottons

Structural variations (SVs) have long been described as being involved in the origin, adaption, and domestication of species. However, the underlying genetic and genomic mechanisms are poorly understood. Here, we report a high-quality genome assembly of Gossypium barbadense acc. Tanguis, a landrace that is closely related to formation of extra-long-staple (ELS) cultivated cotton. An SV-based pan-genome (Pan-SV) was then constructed using a total of 182 593 non-redundant SVs, including 2236 inversions, 97 398 insertions, and 82 959 deletions from 11 assembled genomes of allopolyploid cotton. The utility of this Pan-SV was then demonstrated through population structure analysis and genome-wide association studies (GWASs). Using segregation mapping populations produced through crossing ELS cotton and the landrace along with an SV-based GWAS, certain SVs responsible for speciation, domestication, and improvement in tetraploid cottons were identified. Importantly, some of the SVs presently identified as associated with the yield and fiber quality improvement had not been identified in previous SNP-based GWAS. In particular, a 9-bp insertion or deletion was found to associate with elimination of the interspecific reproductive isolation between Gossypium hirsutum and G. barbadense. Collectively, this study provides new insights into genome-wide, gene-scale SVs linked to important agronomic traits in a major crop species and highlights the importance of SVs during the speciation, domestication, and improvement of cultivated crop species.

Melatonin Promotes the Development of Secondary Hair Follicles in Adult Cashmere Goats by Activating the Keap1-Nrf2 Signaling Pathway and Inhibiting the Inflammatory Transcription Factors NFκB and AP-1.

Exogenous melatonin (MT) has been used to promote the growth of secondary hair follicles and improve cashmere fiber quality, but the specific cellular-level mechanisms involved are unclear. This study was carried out to investigate the effect of MT on the development of secondary hair follicles and on cashmere fiber quality in cashmere goats. The results showed that MT improved secondary follicle numbers and function as well as enhanced cashmere fiber quality and yield. The MT-treated goat groups had high secondary-to-primary ratios (S:P) for hair follicles, greater in the elderly group (p < 0.05). Antioxidant capacities of secondary hair follicles improved fiber quality and yield in comparison with control groups (p < 0.05/0.01). Levels of reactive oxygen and nitrogen species (ROS, RNS) and malondialdehyde (MDA) were lowered (p < 0.05/0.01) by MT. There was significant upregulation of antioxidant genes (for SOD-3; GPX-1; NFE2L2) and the protein of nuclear factor (Nrf2), and downregulation of the Keap1 protein. There were significant differences in the expression of genes for secretory senescence-associated phenotype (SASP) cytokines (IL-1β, IL-6, MMP-9, MMP-27, CCL-21, CXCL-12, CXCL-14, TIMP-1,2,3) plus their protein of key transcription factors, nuclear factor kappa B (NFκB) and activator protein-1 (AP-1), in comparison with the controls. We concluded that MT could enhance antioxidant capacity and reduce ROS and RNS levels of secondary hair follicles through the Keap1-Nrf2 pathway in adult cashmere goats. Furthermore, MT reduced the expression of the SASP cytokines genes by inhibiting the protein of NFκB and AP-1 in the secondary hair follicles in older cashmere goats, thus delaying skin aging, improving follicle survival, and increasing the number of secondary hair follicles. Collectively, these effects of exogenous MT enhanced the quality and yield of cashmere fibers, especially at 5-7 years old.

Improving Fiber Quality Output by Improving the Roll Box of the Gin Saw

Improving Fiber Quality Output by Improving the Roll Box of the Gin Saw

Genome-wide artificial introgressions of Gossypium barbadense into G. hirsutum reveal superior loci for simultaneous improvement of cotton fiber quality and yield traits

IntroductionThe simultaneous improvement of fiber quality and yield for cotton is strongly limited by the narrow genetic backgrounds of Gossypium hirsutum (Gh) and the negative genetic correlations among traits. An effective way to overcome the bottlenecks is to introgress the favorable alleles of Gossypium barbadense (Gb) for fiber quality into Gh with high yield. ObjectivesThis study was to identify superior loci for the improvement of fiber quality and yield. MethodsTwo sets of chromosome segment substitution lines (CSSLs) were generated by crossing Hai1 (Gb, donor-parent) with cultivar CCRI36 (Gh) and CCRI45 (Gh) as genetic backgrounds, and cultivated in 6 and 8 environments, respectively. The kmer genotyping strategy was improved and applied to the population genetic analysis of 743 genomic sequencing data. A progeny segregating population was constructed to validate genetic effects of the candidate loci. ResultsA total of 68,912 and 83,352 genome-wide introgressed kmers were identified in the CCRI36 and CCRI45 populations, respectively. Over 90 % introgressions were homologous exchanges and about 21 % were reverse insertions. In total, 291 major introgressed segments were identified with stable genetic effects, of which 66(22.98 %), 64(21.99 %), 35(12.03 %), 31(10.65 %) and 18(6.19 %) were beneficial for the improvement of fiber length (FL), strength (FS), micronaire, lint-percentage (LP) and boll-weight, respectively. Thirty-nine introgression segments were detected with stable favorable additive effects for simultaneous improvement of 2 or more traits in Gh genetic background, including 6 could increase FL/FS and LP. The pyramiding effects of 3 pleiotropic segments (A07:C45Clu-081, D06:C45Clu-218, D02:C45Clu-193) were further validated in the segregating population. ConclusionThe combining of genome-wide introgressions and kmer genotyping strategy showed significant advantages in exploring genetic resources. Through the genome-wide comprehensive mining, a total of 11 clusters (segments) were discovered for the stable simultaneous improvement of FL/FS and LP, which should be paid more attention in the future.

Analysis of the MIR396 gene family and the role of MIR396b in regulating fiber length in cotton.

Cotton fiber is one of the most important natural raw materials in the world textile industry. Improving fiber yield and quality has always been the main goal. MicroRNAs, as typical small noncoding RNAs, could affect fiber length during different stages of fiber development. Based on differentially expressed microRNA in the two interspecific backcross inbred lines (BILs) with a significant difference in fiber length, we identified the miR396 gene family in the two tetraploid cotton genomes and found MIR396b_D13 as the functional precursor to produce mature miR396 during the fiber elongation stage. Among 46 target genes regulated by miR396b, the GROWTH-REGULATING FACTOR 5 gene (GRF5, Gh_A10G0492) had a differential expression level in the two BILs during fiber elongation stage. The expression patterns indicated that the miR396b-GRF5 regulatory module has a critical role in fiber development. Furthermore, virus-induced gene silencing (VIGS) of miR396b significantly produced longer fiber than the wild type, and the expression level of GRF5 showed the reverse trends of the miR396b expression level. The analysis of co-expression network for the GRF5 gene suggested that a cytochrome P450 gene functions as an allene oxide synthase (Gh_D06G0089, AOS), which plays a critical role in jasmonate biosynthetic pathway. In conclusion, our results revealed that the miR396b-GRF5 module has a critical role in fiber development. These findings provide a molecular foundation for fiber quality improvement in the future.

Impact of Cover Crops and Nitrogen on Cotton Fiber Cellulose and Quality Traits

ABSTRACT Fiber quality varies depending on the fruit position of the cotton plant. Nitrogen (N) availability can alter fruiting dynamics and, consequently, fiber quality. The current study evaluated the effect of cover crops and N availability on cellulose content and fiber quality in different plant positions. The experiment was carried out in Presidente Bernardes, São Paulo, Brazil. Experiment design was a split-plot in completely randomized block design with five replicates. Cover crops were allocated: Fallow (F), Velvet bean (VB), Ruzigrass (Urochloa ruziziensis) (R), Inoculated ruzigrass (IR) (Azospirillum), Ruzigrass + velvet bean (R+VB) and Inoculated ruzigrass + velvet bean (IR+VB); and N rates (80 and 120 kg ha−1) in the sub-plots. Cellulose content in the lower, middle, and upper third of the plants were evaluated at 15 and 30 days after anthesis (DAA) and at harvest. At 15 and 30 DAA, the cellulose content was higher in the lower third in most treatments, except in the treatment with ruzigrass (120 N), which was higher in the upper third. Fibers with higher quality and final cellulose content are in the lower parts of the plant, and IR+VB improved fiber quality by providing applications with lower rates of N.

Alpaca breeding in Peru: From individual initiatives towards a national breeding programme?

Alpacas play an important role in Andean agriculture in Peru as a source of income for about 82,000 families. Although there are various national laws regulating alpaca keeping and breeding, and there are also government plans to introduce a national breeding programme, alpaca breeding takes place in individual, isolated initiatives. This study aims to show how these individual initiatives work, what challenges they face, but also what plans there are for the future and to derive policy and research recommendations. A total of 8 persons, who are responsible for currently running breeding programmes, were interviewed using a questionnaire. Breeding programmes for white Huacaya alpacas are implemented by private companies, but also farmers and a farmers' cooperative. Improving fibre quality by reducing the mean fibre diameter is the most important breeding objective, often in combination with increasing fibre quantity. Besides subjective selection criteria, objective criteria (laboratory analyses of the fibre) are also used. Reproduction technologies such as artificial insemination or embryo transfer do not play a role, as they are too costly and have low success rates. The potential use of genomic information is considered positive. Lack of well-trained personnel, missing interest of cooperative members, high laboratory costs for fibre analysis, volatile fibre prices and feed shortages were mentioned as mayor challenges. All participants of the study plan to further consolidate and expand their breeding programmes in the future. In principle, the introduction of a national breeding programme was assessed positively, but opinions differed strongly on the concrete implementation. Therefore, an open dialogue with the different stakeholders is needed to get a common breeding programme on track.

Loss and Gain in Potential Distribution of Threatened Wild Cotton Gossypium thurberi in Mexico under Future Climate

Gossypium thurberi, a threatened wild cotton species native to northern Mexico and southwestern USA, is globally important because its agronomic traits can be introgressed into cultivated species to improve fiber quality and resistance to biotic and abiotic stressors. However, studies on the current and future potential distribution of the species are scarce. The objectives of this study were (1) to develop a distribution model of G thurberi using a Geographic Information System platform, (2) determine environmental factors that influence the current distribution of the species in Mexico, and (3) estimate the potential distribution of the species under current and future climates. We analyzed the following variables: Annual Available Soil Water (mm year−1, AASW), Flowering Growing Degree Days (FGDD), absolute minimum temperature (°C, Tminabs), and altitude (amsl, ALT). Results showed that the current potential distribution of G. thurberi in northern Mexico, estimated at 112,727 square kilometers, is projected to be drastically reduced by 77 and 86%, considering a possible increase in temperature of 1.5 °C and 2 °C in near-future (2021–2040) and mid-future (2041–2060) climates, respectively, and a 100 mm reduction in average annual precipitation under both climates. The greatest reduction will be in areas in Sonora (Mexico) adjoining Arizona (USA), where the largest populations of the species are currently reported. AASW, FGDD, and ALT jointly influence the distribution of G. thurberi, with AASW as the dominant factor under future climate change. The areas that may continue to harbor populations of G. thurberi under future climate will present AASW of 0.2–55.6 mm year−1, FGDD of 242–547, and ALT between 550 and 1561 amsl. The projected future potential distribution in the country includes new suitable areas, including one in the Trans-Mexican Volcanic Belt, that may serve as refuge areas. The findings can contribute to the design of more precise collection efforts and conservation strategies to prevent species extinction.

Genetic engineering of cotton: current status and perspectives

Currently, several species of the genus Gossypium are cultivated in agriculture to produce fiber. Cotton has been cultivated for a long time, however, many aspects of its cultivation and processing are still researched. Writing about the cultivation of cotton, it is worth mentioning the fundamental problems of its processing. For example, the amounts of pesticides used in the cultivation of cotton are greater than for any other crop. Chemicals sprayed on cotton fields are washed away from the fields and, reaching the fresh water sources, pollute them, causing significant damage to the environment. Fortunately, such challenges can be solved by switching to the cultivation of transgenic cotton. Transgenic cotton has already brought many important environmental, social and economic benefits, including reduce of the used pesticides, indirectly increasing of yield, minimizing environmental pollution, reducing the labor force involved and economic costs.Today, the main methods of obtaining transgenic cotton lines are still agrobacterial transformation and biolistics. In recent years, however, innovative methods of transformation have also been developed. For example, the introduction of genetic material mediated by a pollen tube for the cultivation of commercial transgenic cotton is actively used in China. Although in recent decades transgenic lines resistant to diseases, abiotic stresses and with improved fiber quality have been obtained, the dominant position in the market of transgenic cotton is still occupied by lines of plants resistant to insects and herbicides. All the above indicates an insufficient degree of integration between institutes that introduce new advanced developments and agricultural industry.In this review the results of research involving the cultivation and genetic modification of cotton were collected and summarized. The main methods of genetic transformation of cultivated representatives of the genus Gossypium, both actively used at present and still under development, were considered. The most remarkable transgenic lines were also described, among which both those that have already entered agricultural industry and those that have only recently been obtained. Thus, the reader will be able to get a general idea of the current achievements in the field of cotton genetic modification.

Relationships between the incidence and degree of medullation with the diameter of alpaca fibers evaluated using a novel device based on artificial intelligence

The presence of medullated fibers affects the textile processing, comfort and appeal of alpaca apparel. Measuring the incidence of medullated fibers is slow and expensive. Previous reports of the incidence of medullated fibers are often based on small test samples. The objectives of this work were to: (1) evaluate the Fiber Med device which uses artificial intelligence technology to rapidly and accurately identify the incidence of alpaca fibers according to their type of medullation and determines average fiber diameter (AFD); and (2) to relate the incidence of medullated fibers to a range of animal and fiber characteristics including age of alpaca at shearing, sex of alpaca, breed (Huacaya, Suri), location, and AFD. This study examined fiber from two locations, using 302 alpacas from two breeds and six age groups. Over 630,000 fibers were assessed (average per sample 2112) with AFD 22.1 μm (range 15.5–33.3 μm). Fiber medullation was categorized as either not present (58.6%; AFD 19.6 μm), fragmented (17.1%; 23.0 μm), discontinuous (7.6%; 25.6 μm), continuous (15.4%; 28.6 μm) or strongly medullated (1.3%; 37.8 μm). After appropriate data transformation, analysis of variance, linear and multiple regression analyses were performed to determine relationships between total medullation, AFD, location, breed, sex and age at shearing. There were significant differences in total medullation between location, breed and age at shearing but not sex of alpaca. However, in multiple regression analyses, once AFD was included in models, neither sex nor age at shearing was significant. AFD alone explained over 70% of the variation in total medullation. Differences in the incidence of the degree of medullation between age groups and marketing categories determined using AFD, were associated with differences in AFD. The differences due to location were explained by genetic selection programs to reduce AFD at one location. There was a persistent small incidence of strongly medullated fibers at all age groups (mean range 0.33–1.14%), locations, breeds and sexes and a higher incidence in fiber with AFD > 26.5 μm (mean range 2.87–6.50%). Suri alpaca had a lower incidence of medullation than Huacaya alpaca. Since the Fiber Med device provided a direct, fast and low-cost measurement of the incidence of medullation it appears to be a practical option for use in programs to improve fiber quality, marketing and processing of white alpaca fiber. To reduce strongly medullated fibers in all categories of alpaca fiber, the measurement of the incidence of medullation should become a routine assessment in alpaca breeding programs.

Fiber-specific overexpression of GhACO1 driven by E6 promoter improves cotton fiber quality and yield

Cotton (Gossypium hirsutum) is the most important fiber crop globally and there is an incentive to improve cotton fiber yield and quality to meet the growing market demand. 1-Aminocyclopropane-1-Carboxylic Acid Oxidase (ACO) has been identified as a rate-limiting enzyme in the biosynthesis of ethylene that is known to play a pivotal regulatory role in fiber development. According to transcriptomic data analysis, GhACO1 is preferentially expressed at fiber elongation stage in a number of G. hirsutum varieties, suggestive of its involvement in regulating fiber development. Ethylene is known to cause premature senescence, and to abrogate its potential negative effects on plant growth by constitutive overexpression of GhACO1, a fiber-specific promoter E6 that imparts strong transcriptional activity in fiber elongation stage was employed to drive GhACO1 expression to improve fiber quality. The E6::GhACO1 cotton transgenic lines showed substantial improvements in fiber length, fiber strength and fiber yield relative to wild type. Exogenous application of pyrazinecarboxylic acid that is an effective inhibitor of ACO enzyme inhibited fiber elongation in ovule culture, validating that GhACOs may improve fiber quality by increasing ethylene levels. Furthermore, RNA-Seq analysis showed that upregulation of GhACO1 can activate the transcription of genes that are involved in hydrogen peroxide metabolism, cell wall loosening and cytoskeleton arrangement, thereby promoting fiber elongation. These findings suggest that GhACO1 is a key regulator of fiber development, and the application of “E6::GhACO1” strategy breaks the negative correlation between fiber quality and fiber yield, providing a novel route in formulating fiber improvement strategies in cotton.

Divergence of two cultivated allotetraploid cottons unveiled by single-molecule long-read expression sequencing

Allotetraploid Gossypium hirsutum and G. barbadense are two major cultivated cotton species that have different fiber traits. Research into the molecular basis of those differences is limited by a lack of accurate, complete transcript profiles. Here we adopted joint PacBio Iso-seq and RNA-seq to investigate genome-wide transcript profiles and uncover differences in the expression between G. hirsutum acc. TM-1 and G. barbadense cv. Hai7124. We obtained 178,867 full-length transcripts covering 60.0% of gene loci in the TM-1 reference annotation, including 7846 transcription factors and 3122 lncRNAs. Moreover, we identified 304 and 610 high-confidence (HC) species-specific transcripts in TM-1 and Hai7124, respectively, along with 4156 and 4381 tissue-specific transcripts. Our results update the reference genome annotation and also provide potential resources for studying the molecular mechanisms of fiber development. We are thus able to promote improvements in cotton fiber quality. • Produced 178,867 full-length transcripts from 10 Gossypium hirsutum and G. barbadense tissues using single-molecule sequencing technology. • By contrast, species-specific and tissue-specific transcripts were identified. • Helps to uncover the molecular mechanisms underlying fiber differences at the transcript level in cotton.

Proteomics of Cotton Fiber Development

Cotton is one of the major sources for natural fiber with strong commercial relevance. Now a day, there is a substantial demand for the extra-long, strong and fine cotton fibres are the major choices of modern textile industry. The most efficient way to improve fiber quality is through breeding. However, it is a big challenge for cotton breeders to develop a cultivar having good fiber quality along with higher yield because a negative genetic correlation widely exists between quality and yield. However, complete draft genome sequence of cotton is now available, but functional genomic studies remain in their infancy, as this exhibit genetic constrains like recalcitrance and complex genome. Proteomics is an established complementary tool to genomics provides a powerful tool for functional analysis of cotton fiber productivity. In this review, a special emphasis is given to cotton fiber proteomics in response to fiber biogenesis, fiber quality and fiber colour that will give a better understanding for molecular basis of acquisition of fiber developmental mechanism. Various biological and molecular pathways that are mostly carried out and controlled by proteins guide this dynamic process of cotton fibre development. An integrating proteome data with genome information from cotton will provide exciting outcome for high quality fiber and yield to attain long-term goals of cotton sustainable production.

Cotton Breeding in Australia: Meeting the Challenges of the 21st Century.

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) cotton breeding program is the sole breeding effort for cotton in Australia, developing high performing cultivars for the local industry which is worth∼AU$3 billion per annum. The program is supported by Cotton Breeding Australia, a Joint Venture between CSIRO and the program’s commercial partner, Cotton Seed Distributors Ltd. (CSD). While the Australian industry is the focus, CSIRO cultivars have global impact in North America, South America, and Europe. The program is unique compared with many other public and commercial breeding programs because it focuses on diverse and integrated research with commercial outcomes. It represents the full research pipeline, supporting extensive long-term fundamental molecular research; native and genetically modified (GM) trait development; germplasm enhancement focused on yield and fiber quality improvements; integration of third-party GM traits; all culminating in the release of new commercial cultivars. This review presents evidence of past breeding successes and outlines current breeding efforts, in the areas of yield and fiber quality improvement, as well as the development of germplasm that is resistant to pests, diseases and abiotic stressors. The success of the program is based on the development of superior germplasm largely through field phenotyping, together with strong commercial partnerships with CSD and Bayer CropScience. These relationships assist in having a shared focus and ensuring commercial impact is maintained, while also providing access to markets, traits, and technology. The historical successes, current foci and future requirements of the CSIRO cotton breeding program have been used to develop a framework designed to augment our breeding system for the future. This will focus on utilizing emerging technologies from the genome to phenome, as well as a panomics approach with data management and integration to develop, test and incorporate new technologies into a breeding program. In addition to streamlining the breeding pipeline for increased genetic gain, this technology will increase the speed of trait and marker identification for use in genome editing, genomic selection and molecular assisted breeding, ultimately producing novel germplasm that will meet the coming challenges of the 21st Century.