Improve Fiber Quality Research Articles

Natural variation in GhROPGEF5 contributes to longer and stronger cotton fibers.

Length and strength are key parameters impacting the quality of textiles that can be produced from cotton fibers, and therefore are important considerations in cotton breeding. Through map-based cloning and function analysis, we demonstrated that GhROPGEF5, encoding a ROP guanine nucleotide exchange factor, was the gene controlling fiber length and strength at qFSA10.1. Evolutionary analysis revealed that a base deletion in the third exon of GhROPGEF5 resulting in superior fiber length and strength was a rare mutation occurring in a tiny percentage of Upland cottons, with reduced fiber yield hindering its spread. GhROPGEF5 interacted with and activated GhROP10. Knockout or mutation of GhROPGEF5 resulted a loss of the ability to activate GhROP10. Knockout of GhROPGEF5 or GhROP10 affected the expression of many downstream genes associated with fiber elongation and secondary wall deposition, prolonged fiber elongation and delayed secondary wall deposition, producing denser fiber helices and increasing fiber length and strength. These results revealed new molecular aspects of fiber development and revealed a rare favorable allele for improving fiber quality in cotton breeding.

Association of GhGeBP genes with fiber quality and early maturity related traits in upland cotton

Transcription Factors (TFs) are key regulators of how plants grow and develop. Among the diverse TF families, the Glabrous-enhancer binding protein (GeBP) family plays a key role in trichome initiation and leaf development. The specific roles of GeBP TFs in plants remain largely unexplored, although GeBP transcription factors play important roles in plants. This study identified 16 GhGeBP genes in Gossypium hirsutum, ranging from 534 bp (GhGeBP14) to 1560 bp (GhGeBP2). Phylogenetic analysis grouped 16 GhGeBP genes clustered into three subgroups, unevenly distributed across 14 chromosomes. Analysis of the cis-acting elements revealed 408 motifs in the 2 kb upstream regions of the promoters, including stress-responsive, phytohormone-responsive, and light-responsive elements. Tissue-specific expression analysis showed 8 GhGeBP genes were highly expressed across all tissues, while GhGeBP4 and GhGeBP12 were down-regulated under conditions of drought, salt, cold, and heat stress. A genome-wide association study (GWAS) identified GhGeBP4 was associated with fiber micronaire (FM) and fiber strength (FS), while GhGeBP9 was linked to the node of the first fruiting branch (NFFB) and flowering time (FT). Haplotype analysis revealed that GhGeBP4-HAP2 exhibited higher fiber quality traits, while GhGeBP9-HAP2 was associated with early maturity. The results of this study offer significant insights that are worthy of further investigation into the role of the GhGeBP gene family in G. hirsutum and promising targets for marker-assisted selection strategies in cotton breeding programs, particularly for improving fiber quality and early maturity traits.

Demonstrating almost half of cotton fiber quality variation is attributed to climate change using a hybrid machine learning-enabled approach

Understanding the effects of climate change on cotton fiber quality will reduce the risks to production caused by global warming. Machine learning algorithms are effective for forecasting climate impacts on crops. However, the impact of climate change on cotton fiber quality is unclear. Hence, a hybrid machine learning-enabled approach, the Bayesian model average (BMA) method with multiple machine learning algorithms (linear regressor, SVR, RFR, GBDT, LightGBM, and XGBoost) and bootstrap resampling, was developed to explore the impact and screen the important climatic factors affecting various traits of fiber quality. On the basis of fiber quality data from 1033 test stations across Xinjiang, China, from 2016 to 2022, the explained variance for climate change in the hybrid machine learning model was as follows: 44.72 %–50.55 % for white cotton grade, 44.06 %–53.95 % for length, 51.72 %–56.81 % for micronaire, 32.70 %–49.50 % for length uniformity, and 45.66 %–53.09 % for strength in the 1000 bootstrapping samples. In addition, recursive feature elimination with cross-validation (RFECV) was used to select the optimal feature set and calculate the contribution of each feature. The variability in micronaire in the hybrid model was affected primarily by climate factors, such as the daily minimum temperature, rainfall, and wind speed, whereas the other quality traits were affected mainly by radiation-related climatic indicators. The climate during the harvest stage in October had a significant effect on cotton quality, explaining 33.0 % of the variance in white cotton grade, 32.1 % in length, and 48.3 % in fiber strength. Conversely, the climate during the boll opening and early harvest stages in September had a greater influence on micronaire and length uniformity, accounting for 21.4 % and 37.2 % of the variance, respectively. This study highlights that climate change explains nearly 50 % of the variation in fiber quality, with the influence being notably more considerable during the later stages of the cotton growth period. These findings clarify the uncertainty in the impact of climate change on cotton fiber quality considering the uncertainty of the single machine model and model errors. Equally important, this information can be valuable for farmers and growers seeking to improve fiber quality under climate change.

GhGRF4/GhARF2-GhGASA24 module regulates fiber cell wall thickness by modulating cellulose biosynthesis in upland cotton (Gossypium hirsutum).

Fiber elongation rate is an essential characteristic of cotton fiber in the textile industry, yet it has been largely overlooked in genetic studies. Gibberellins (GAs) and auxin (IAA) are recognized for their role in directing numerous developmental processes in plants by influencing cell differentiation and elongation. However, the degree to which GA-IAA interaction governs cellular elongation in cotton fiber cells remains to be fully understood. In this study, we identified a causal gene, Gibberellic Acid-Stimulated in Arabidopsis 24 (GhGASA24), that appears to be responsible for fiber elongation rate via regulating fiber cell wall thickness. Subsequent experiments revealed that GhGASA24 influences cell wall formation by promoting the expression of GhCesA8 and GhCesA10. Our findings suggest that Auxin Response Factor 2 (GhARF2) regulates fiber elongation rate by directly binding to the AuxRE elements in GhGASA24 promoter. In addition, we identified Growth Regulation Factor 4 (GhGRF4) as a transcription factor that interacts with GhARF2 to form a heterodimer complex, which also transcriptionally activates GhGASA24. Intriguingly, GhGRF4 regulates GhARF2 expression by directly binding to its promoter, thereby acting as a cascade regulator to enhance the transcriptional levels of GhGASA24. We propose that the GhGRF4/GhARF2-GhGASA24-GhCesAs module may contribute to fiber cell wall thickness by modulating cellulose biosynthesis, and provide a theoretical basis for improvement of fiber quality.

The molecular anatomy of cashmere goat hair follicle during cytodifferentiation stage

BackgroundCashmere, named as “soft gold”, derives from the secondary hair follicles (SHFs) of cashmere goat which is vital to Northwest China’s economy. The cytodifferentiation stage (E120), mirroring the complete hair follicle (HF) structure of adult goats and marking a critical phase in SHF development. Therefore, this study aims to enhance the understanding of SHF development and its impact on fiber quality, informing breeding strategies.ResultsFrom the scRNA-seq data analysis, the intricate processes and transcriptional dynamics of inner layer cell differentiation of HFs were unveiled in this study. we identified nine cell populations during cytodifferentiation and key structures such as the hair shaft and inner root sheath. And we discovered three main inner layer lineages and seven subpopulations, clarifying their roles in specialization and signaling. Pseudotime mapping analysis showed cell evolution from early stage to mature stages marked by unique gene expressions, and the intermediate stage on the differentiation of each lineage was revealed. The identification and spatial localization of specific transcription factors, such as GATA3, LEF1 and PRDM1, as well as keratin genes highlight regulatory pathways involved in HF development, which was further validated by immunofluorescence. These findings suggested the potential strategies to improve fiber quality, and the discovery of diverse cell types and their developmental molecular mechanisms, particularly in this species-specific context, offered a nuanced view of the regulatory mechanisms driving HF development in cashmere goats.ConclusionOverall, these findings provide a systematic molecular atlas of skin, defining three major branches and cell states of inner layer cells of HF, and determining how the branch-specific transcription factors, keratins, and signals coordinate HF morphogenesis during cytodifferentiation stage. This research not only advances skin tissue research in goats but also holds broader implications for the understanding of HF regeneration and development across various species.

Insights into the genetic divergence in Asiatic cotton (Gossypium arboreum L.) germplasm for fibre-quality traits

Abstract Asiatic cotton (Gossypium arboreum L.) has evolved in the Indian subcontinent and is known for its adaptability to low-input management conditions. In the present study, 300 diverse G. arboreum lines, including 100 Nandyal arboreum breeding lines (NAB), 132 Arboreum germplasm collections (AGC) and 68 long-linted arboreum genotypes (LLA), were evaluated for fibre quality to assess the diversity among them and to identify promising genotypes with desirable fibre traits. Significant variations were observed among the genotypes for the studied fibre-quality traits. Principal component analysis showed that the traits micronaire (Mic) and elongation percentage (E%) followed by upper half mean length (UHML) and bundle tenacity (tenacity) were the most significant contributors to variation. Cluster analysis based on the Euclidian distance method showed 16 clusters among 300 G. arboreum genotypes. The genotypes in cluster 4 have desirable UHML, tenacity and UI (uniformity index) traits, and cluster 12 has Mic and E% traits. Furthermore, the number of genotypes with desirable fibre-quality traits was found to be higher in the AGC group than in the LLA and NAB groups. The trait tenacity followed by the UHML showed relatively higher Shannon–Weiner diversity index values across different genotypic groups. Based on the superior performance, the genotypes PA 847, PA 809, PA 837, PA 863, NDLA 3147-2, NDLA 2974 and NDLA 3081 were found to be having desirable fibre traits. The identified promising genotypes are valuable genetic resources for improving fibre quality in G. arboreum cotton.

Simultaneous improvement of fiber yield and quality in upland cotton (Gossypium hirsutum L.) by integration of auxin transport and synthesis

Simultaneous improvement of fiber yield and quality in upland cotton (Gossypium hirsutum L.) by integration of auxin transport and synthesis

Heterosis and Inbreeding Depression Studies for Fibre Quality Traits in Upland Cotton (Gossypium hirsutum L.)

Cotton hybrids have its own advantage than varieties in yield and fibre properties. Heterosis breeding helps in identifying F1 hybrids and in creating variability. The chief intention of any hybridization programme is to combine all the desirable genes present in two or more parents into a single genetic background. This investigation helped in identifying the extent of heterosis in crosses among four families in upland cotton (Gossypium hirsutum L.) which was conducted at college Farm during kharif 2021-23. The all 4 hybrids were derived by generation mean analysis study which were analysed for fibre quality traits in a Compact Family Block Design. For traits like Ginning percentage, uniformity index, Upper Half Mean Length, Lint index, and Fibre strength, most of the crosses showed positive and significant relative heterosis. While, heterobeltiosis was also found positive and significant for ginning percentage, uniformity index, Upper half mean length and fibre strength for most of the crosses under study. Most of the crosses under study also showed little inbreeding depression for traits like ginning percentage, uniformity index and fibre strength. Thus, by exploiting the benefits of heterosis while mitigating risks associated with inbreeding depression may lead to the development of superior hybrid varieties with consistently improved fibre quality.

Genetic Regulatory Perturbation of Gene Expression Impacted by Genomic Introgression in Fiber Development of Allotetraploid Cotton.

Interspecific genomic introgression is an important evolutionary process with respect to the generation of novel phenotypic diversity and adaptation. A key question is how gene flow perturbs gene expression networks and regulatory interactions. Here, an introgression population of two species of allopolyploid cotton (Gossypium) to delineate the regulatory perturbations of gene expression regarding fiber development accompanying fiber quality change is utilized. De novo assembly of the recipient parent (G. hirsutum Emian22) genome allowed the identification of genomic variation and introgression segments (ISs) in 323 introgression lines (ILs) from the donor parent (G. barbadense 3-79). It documented gene expression dynamics by sequencing 1,284 transcriptomes of developing fibers and characterized genetic regulatory perturbations mediated by genomic introgression using a multi-locus model. Introgression of individual homoeologous genes exhibiting extreme low or high expression bias can lead to a parallel expression bias in their non-introgressed duplicates, implying a shared yet divergent regulatory fate of duplicated genes following allopolyploidy. Additionally, the IL N182 with improved fiber quality is characterized, and the candidate gene GhFLAP1 related to fiber length is validated. This study outlines a framework for understanding introgression-mediated regulatory perturbations in polyploids, and provides insights for targeted breeding of superior upland cotton fiber.

Selection of productive early maturing cotton genotypes with improved fibre quality parameters

The purpose of this article was to study productivity and fibre quality of different cotton genotypes under conditions of Turkestan region of Kazakhstan to determine the most promising genotypes for commercial cultivation. Four genotypes were selected: Tashkent-6, Maktaral-5027, Namangan-1 and Bukhara-8. The study included analysis of such parameters as germination and sprouting time, plant height, flowering and maturity time, yield, number of bolls and fibre quality characteristics. The results showed that Tashkent-6 and Maktaral-5027 had the best parameters: yield 3.8 t/ha and 3.5 t/ha, flowering time 55 days and maturity 120 days, plant height 120 cm and 115 cm, number of bolls 45 and 42. The fibre quality of these genotypes was also high: length 32 mm and 31 mm, tensile strength 30 g/tex and 29 g/tex, fineness 2.5 dtex and 2.6 dtex. Namangan-1 and Bukhara-8 genotypes showed moderate results: yield 3.2 t/ha and 3.0 t/ha, flowering time 60 days and ripening time 130 days, plant height 110 cm and 105 cm, number of bolls 40 and 38, fibre length 30 mm and 29 mm, tensile strength 28 g/tex and 27 g/tex, fineness 2.8 dtex and 2.9 dtex. Statistical analysis confirmed the significance of differences between genotypes. The results of the study confirmed high productivity and fibre quality of genotypes Tashkent-6 and Maktaral-5027, which makes them promising for commercial cultivation in Kazakhstan, while genotypes Namangan-1 and Bukhara-8 also have potential for certain agronomic conditions

GhWRKY40 Interacts with an Asparaginase GhAPD6 Involved in Fiber Development in Upland Cotton (Gossypium hirsutum L.).

Fiber quality improvement is a primary goal in cotton breeding. Identification of fiber quality-related genes and understanding the underlying molecular mechanisms are essential prerequisites. Previously, studies determined that silencing the gene GhWRKY40 resulted in longer cotton fibers; however, both the underlying mechanisms and whether this transcription factor is additionally involved in the regulation of cotton fiber strength/fineness are unknown. In the current study, we verified that GhWRKY40 influences the fiber strength, fiber fineness, and fiber surface structure by using virus-induced gene silencing (VIGS). Potential proteins that may interact with the nucleus-localized GhWRKY40 were screened in a yeast two-hybrid (Y2H) nuclear-system cDNA library constructed from fibers at 0, 10, and 25 days post-anthesis (DPA) in two near-isogenic lines differing in fiber length and strength. An aspartyl protease/asparaginase-related protein, GhAPD6, was identified and confirmed by Y2H and split-luciferase complementation assays. The expression of GhAPD6 was approximately 30-fold higher in the GhWRKY40-VIGS lines at 10 DPA and aspartyl protease activity was significantly upregulated in the GhWRKY40-VIGS lines at 10-20 DPA. This study suggested that GhWRKY40 may interact with GhAPD6 to regulate fiber development in cotton. The results provide a theoretical reference for the selection and breeding of high-quality cotton fibers assisted by molecular technology.

Dissecting the Superior Drivers for the Simultaneous Improvement of Fiber Quality and Yield Under Drought Stress Via Genome-Wide Artificial Introgressions of Gossypium barbadense into Gossypium hirsutum.

Global water scarcity and extreme weather intensify drought stress, significantly reducing cotton yield and quality worldwide. Drought treatments are conducted using a population of chromosome segment substitution lines generated from E22 (G. hirsutum) and 3-79 (G. barbadense) as parental lines either show superior yields or fiber quality under both control and drought conditions. Fourteen datasets, covering 4 yields and 4 quality traits, are compiled and assessed for drought resistance using the drought resistance coefficient (DRC) and membership function value of drought resistance (MFVD). Genome-wide association studies, linkage analysis, and bulked segregant analysis are combined to analyze the DR-related QTL. A total of 121 significant QTL are identified by DRC and MFVD of the 8 traits. CRISPR/Cas9 and virus-induced gene silencing techniques verified DRR1 and DRT1 as pivotal genes in regulating drought resistant of cotton, with hap3-79 exhibiting greater drought resistance than hapE22 concerning DRR1 and DRT1. Moreover, 14 markers with superior yield and fiber quality are selected for drought treatment. This study offers valuable insights into yield and fiber quality variations between G. hirsutum and G. barbadense amid drought, providing crucial theoretical and technological backing for developing cotton varieties resilient to drought, with high yield and superior fiber quality.

The lignin riddle in jute: A comparative genomic investigation identifies targets for improving fiber quality

Jute fiber has become more popular in recent years due to its renewability, biodegradability, low manufacturing costs, and wide range of uses. However, one of the major components of fiber is lignin, which impairs the fiber quality and, as a result, makes jute fiber unsuitable for use in the textile industry and biofuel production. The availability of the jute (Corchorus olitorius) genome sequence provides the opportunity to perform a systematic analysis of the gene families and transcription factors specific to the lignin biosynthesis. Here, genome-wide screening was performed to identify the members of gene families associated with lignin biosynthesis in jute. Following this, phylogenetic analysis was carried out with functionally characterized genes involved in lignin biosynthesis of other species. The expression analysis among different tissues and different regions of bark tissue, taking into account fiber developmental stages, is also conducted to identify the genes mainly involved in jute fiber lignification. Fourteen genes and eleven transcription factors belonged to bona fide clades and showed strong expression in highly lignified tissues. Moreover, the transcript levels of these proteins were higher in the bottom bark tissues, which have a higher lignin accumulation compared to the top bark tissues, suggesting these genes were the core lignification genes in fiber formation. Similarly, gene ontology and protein-protein interactions analysis indicated that these genes were mainly involved in lignin biosynthesis and interacted with each other. The identification of the major lignification genes and transcription factors involved in jute fiber development provides a strong foundation for the development of jute cultivars to improve fiber quality.

The functions of laccase gene GhLAC15 in fiber colouration and development in brown-colored cotton.

The monotonicity of color type in naturally colored cottons (NCCs) has become the main limiting factor to their widespread use, simultaneously coexisting with poor fiber quality. The synchronous improvement of fiber quality and color become more urgent and crucial as the demand for sustainable development increases. The homologous gene of wild cotton Gossypium stocksii LAC15 in G. hirsutum, GhLAC15, was also dominantly expressed in the developing fibers of brown cotton XC20 from 5 DPA (day post anthesis) to 25 DPA, especially at the secondary cell wall thickening stage (20 DPA and 25 DPA). In XC20 plants with downregulated GhLAC15 (GhLAC15i), a remarkable reduction in proanthocyanidins (PAs) and lignin contents was observed. Some of the key genes in the phenylpropane and flavonoid biosynthesis pathway were down-regulated in GhLAC15i plants. Notably, the fiber length of GhLAC15i plants showed an obvious increase and the fiber color was lightened. Moreover, we found that the thickness of cotton fiber cell wall was decreased in GhLAC15i plants and the fiber surface became smoother compared to that of WT. Taken together, this study revealed that GhLAC15 played an important role in PAs and lignin biosynthesis in naturally colored cotton fibers. It might mediate fiber color and fiber quality by catalyzing PAs oxidation and lignin polymerization, ultimately regulating fiber colouration and development.

Genome-wide identification of the pectate lyase (PEL) gene family members in Malvaceae, and their contribution to cotton fiber quality

Pectin is a major constituent of the plant cell wall. Pectate lyase (PEL, EC 4.2.2.2) uses anti-β-elimination chemistry to cleave the α-1,4 glycosidic linkage in the homogalacturonan region of pectin. However, limited information is available on the comprehensive and evolutionary analysis of PELs in the Malvaceae. In this study, we identified 597 PEL genes from 10 Malvaceae species. Phylogenetic and motif analyses revealed that these PELs are classified into six subfamilies: Clades I, II, III, IV, Va, and Vb. The two largest subfamilies, Clades I and II, contained 237 and 222 PEL members, respectively. The members of Clades Va and Vb only contained four or five motifs, far fewer than the other subfamilies. Gene duplication analysis showed that segmental duplication played a crucial role in the expansion of the PEL gene family in Gossypium species. The PELs from Clades I, IV, Va, and Vb were expressed during the fiber elongation stage, but nearly all PEL genes from Clades II and III showed no expression in any of the investigated fiber developmental stages. We further performed single-gene haplotype association analysis in 2,001 G. hirsutum accessions and 229 G. barbadense accessions. Interestingly, 14 PELs were significantly associated with fiber length and strength traits in G. barbadense with superior fiber quality, while only eight GhPEL genes were found to be significantly associated with fiber quality traits in G. hirsutum. Our findings provide important information for further evolutionary and functional research on the PEL gene family members and their potential use for fiber quality improvement in cotton.

Genetic and Molecular Regulation of Cotton Fiber Initiation and Elongation

Cotton fiber, a crucial and sustainable resource for global textile production, undergoes a complex five-stage developmental process, encompassing initiation, elongation, transition, secondary cell wall biosynthesis, and maturation. These elongated single-cell fibers originate from the outer ovule epidermis. The development of cotton fibers involves intricate changes in gene expression and physiological processes, resulting in a nearly pure cellulose product that is vital for the global cotton industry. Decoding the genes associated with fiber development enhances our understanding of cotton fiber mechanisms and facilitates the cultivation of varieties with enhanced quality. In recent decades, advanced omics approaches, including genomics, transcriptomics, and proteomics, have played a pivotal role in identifying the genes and gene products linked to cotton fiber development, including the MYB transcription factor family, which coordinates cotton fiber development. Molecular studies have revealed the transcription factors, like MYB, WRKY, Homeodomain Leucine Zipper (HD-ZIP), and basic helix–loop–helix (bHLH), influencing fiber initiation and elongation. The intricate interplay of phytohormones, like auxin, gibberellic acid (GA), brassinosteroids (BRs), jasmonic acid (JA), ethylene, abscisic acid (ABA), and cytokinin, is explored, providing a comprehensive perspective on the shaping of cotton fibers. Numerous candidate genes and cellular processes affecting various aspects of fiber development hold promise for genetic engineering or marker-assisted breeding to improve fiber quality. This review presents a comprehensive overview of key achievements in cotton molecular biology, with a specific emphasis on recent advancements in understanding the transcription factors and phytohormones involved in cotton fiber initiation and elongation.

Insights into genetic diversity and functional significance of the bHLH genes in cotton fiber development

This study investigated the identification and distribution of single nucleotide polymorphisms (SNPs) within basic Helix-Loop-Helix (bHLH) transcription factors (TFs) across diverse cotton (Gossypium hirsutum) accessions, including wild, landrace, and improved varieties. Comprehensive genomic analyses revealed substantial SNP diversity in wild cotton, distinct from that observed in landraces and improved accessions. Comparative analysis showed notable variations in SNP abundance and impact levels across different accessions, with missense SNPs being prevalent. Nucleotide substitution patterns highlighted the dominance of G>A and A>G substitutions. Population genetic analyses unveiled significant genetic diversity within wild accessions and distinct clustering between wild and improved accessions. Temporal expression profiling of bHLH genes during cotton fiber development demonstrated dynamic expression patterns, emphasizing their roles in fiber initiation, elongation, and cellulose biosynthesis. Moreover, association analysis identified SNPs significantly associated within bHLH genes, particularly GhbHLH149, with fiber quality traits, indicating their potential functional significance. Population genetic analyses further revealed evidence of positive selection on GhbHLH149 during cotton improvement. This study provides a comprehensive understanding of SNP diversity, gene expression dynamics, and genetic selection in bHLH genes, offering valuable insights for future cotton breeding efforts aimed at improving fiber quality traits in cotton.

Comparative analysis of key fiber characteristics in white Pima cotton (Gossypium barbadense L.): Native accessions from the Peruvian Amazon

AbstractThe fiber quality of cotton (Gossypium barbadense L.) native to the Peruvian Amazon region is one of the most versatile and essential natural fibers in the Peruvian textile industry. There is little information about the fiber quality traits of cotton genotypes native to the Peruvian Amazon region. This study investigated the fiber quality traits of Peruvian Pima cotton accessions native to the Amazon region of the La Convención Province, Cusco, Peru, to determine the lines with the greatest potential for improving fiber quality in cotton genetic breeding programs. A total of 14 cotton accessions with white fiber color, being 12 accessions of G. barbadense L. (Pima cotton) and two accessions of Gossypium sp. (unknown cotton), were analyzed. The fiber properties determined using the high volume instrument method included seven characteristics. All fiber properties were classified into five quality classes. The data on fiber quality properties were subjected to distribution, correlation, and canonical variable analysis. The results of fiber quality properties showed that the two accessions of Gossypium sp. (unknown cotton) can be promising options to be used as high‐quality fiber progenies in crop genetic breeding programs or can be cultivated by regional farmers for the purpose of producing cotton with high fiber quality. Future investigations could utilize other methods of fiber quality analysis and compare the fiber quality of these cotton accessions native to the Peruvian Amazon region with other cotton species grown worldwide to improve the understanding of Pima cotton fiber quality and its applicability in different contexts of the textile industries.

Pioneering the carbon fiber frontier: A half-century of industry leadership and the road ahead

Polyacrylonitrile (PAN)-based carbon fibers have been in full-scale industrialization for more than 50 years, during which time it has grown at an annual rate of 10–20 % for half a century, a trend that is expected to continue. Throughout this period, the carbon fiber industry has supported the composites industry through a stable global supply and improved fiber quality. Here, we show PAN-based carbon fibers' history and future for this 50-year milestone. The industrialization of carbon fiber began in 1959, when Shindo discovered how to stabilize PAN. The later discovery of comonomers based on the Morita-Baylis-Hilman reaction by Morita in 1966 further enabled industrialization. In addition to the innovativeness of this breakthrough, progress was made in converging technologies which intensified competition and encouraged incremental innovation. In recent years, microstructure control has become increasingly precise: down to the molecular level through incremental innovations, with tensile strength reaching 8.0 GPa and named T1200. Evaluating the carbon fibers’ intrinsic strength by the loop method, where evaluation size is reduced to the order of tens of micrometers, shows that the maximum value of T1200 is very high at 18 GPa. This is almost consistent with the value of 19 GPa predicted using molecular dynamics. Even higher strength can be expected by reducing defects. These performance improvements have already contributed toward carbon neutrality in aircraft and wind power generation. PAN-based carbon fibers will continue to be an important material in the future as further performance improvements and increased mass production are realized.

Straw-derived biochar incorporation improves seedcotton yield and fiber quality by optimizing photosynthetic carbon and nutrients partitioning and boll formation patterns

Synergistic improvement of cotton (Gossypium hirsutum L.) yield and quality is necessary to meet the demands of the textile industry. Straw or biochar addition has been shown to increase boll number and hence yield, while optimizing reproductive growth processes (e.g., accelerating boll formation during the effective boll-setting period) is essential for improving fiber quality. However, it remains unclear how straw and biochar affect boll formation dynamics and whether they can simultaneously improve cotton yield and fiber quality. In order to reveal the mechanism of simultaneous improvement of cotton yield and quality, this study investigated the responses of plant photosynthetic carbon allocation, bud and boll dynamics, seedcotton yield, and fiber quality to different straw returning modes. A 7- year field experiment was performed with four straw treatments: no straw or biochar addition (CK); straw-derived biochar incorporation (SBI); straw incorporation (SI); and straw mulching (SM). The results suggested that SBI, SI and SM remarkably increased the seedcotton yield (24.5–30.7 %, 12.6–20.4 % and 4.7 %-11.0 %), fiber length (3.6–6.7 %, 4.0–9.5 % and 2.4–7.1 %) and fiber strength (8.0–13.0 %, 6.2–10.7 % and 4.4–5.7 %) from 2019 to 2021, compared with CK. There was a strong consistency between seedcotton yield and fiber strength among straw returning modes, and were highest under SBI, followed by SI and SM. Compared with CK, SBI significantly increased nutrients and photosynthetic carbon accumulation in cotton plant, and enhanced their distribution proportion in reproductive organs. This increased the number of fruiting branches, number of fruiting sites and ratio of fruiting sites to fruiting branches, accelerated budding and reduced the shedding rate of buds and bolls. Finally, SBI obtained the highest boll forming rate during the boll formation stage, as well as the highest effective boll number at the harvest stage. Overall, returning straw-derived biochar into soils optimized the allocation of nutrients and photosynthetic carbon in cotton plant, and accelerated the formation of cotton bolls from peak flowering stage to peak boll setting stage, thereby improving seedcotton yield and fiber quality. This work provides practical guidance for improving seedcotton yield, fiber quality, and the utilization of straw resources.