Species determination and CYTB-G143A monitoring of Ramulariopsis spp. isolated from cotton in Brazil

Ramularia leaf spot is a disease of major importance on cotton fields in Brazil due to its effects on yield and cotton fiber quality. Two Ramulariopsis (syn. Ramularia) species, R. gossypii and R. pseudoglycines, are reported as the causal agents of this disease, but it is unknown which species is the most prevalent in Brazilian cotton fields. The goal of this work was to determine the most frequent species occurring on field samples from a molecular monitoring program which sampled from all cotton growing regions in Brazil from 2017 to 2020 seasons. We also used molecular tools for genotyping a region of the Cytb gene for all sampled isolates. Sequencing of an ITS-rDNA region was used for Ramulariopsis species determination, and a DNA fragment from the Cytb gene was amplified, sequenced, and analyzed for all 165 isolates. The ITS-rDNA sequencing confirmed that all isolates belong to the Ramulariopsis, and most notably, all the SNPs observed in this region, are of the R. pseudoglycines species for all 165 isolates, thus all analyzed isolates were assigned to this species. The analysis of the Cytb gene fragment sequenced showed the presence of the G143A substitution, and absence of G137R substitution, in all 165 isolates.

Transcriptome analysis reveals genes potentially related to high fiber strength in a Gossypium hirsutum line IL9 with Gossypium mustelinum introgression

Cotton (Gossypium L.) is the most important fiber crop worldwide. Here, transcriptome analysis was conducted on developing fibers of a G. mustelinum introgression line, IL9, and its recurrent parent, PD94042, at 17 and 21 days post-anthesis (dpa). Differentially expressed genes (DEGs) of PD94042 and IL9 were identified. Gene Ontology (GO) enrichment analysis showed that the annotated DEGs were rich in two main biological processes and two main molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis likewise showed that the annotated DEGs were mainly enriched in metabolic pathways and biosynthesis of secondary metabolites. In total, 52 DEGs were selected as candidate genes based on comparison of the DEGs and GO function annotation information. Quantitative real-time PCR (RT-qPCR) analysis results for 12 randomly selected DEGs were consistent with transcriptome analysis. SNP identification based on G. mustelinum chromatin segment introgression showed that 394 SNPs were identified in 268 DEGs, and two genes with known functions were identified within fiber strength quantitative trait loci (QTL) regions or near the confidence intervals. We identified 52 key genes potentially related to high fiber strength in a G. mustelinum introgression line and provided significant insights into the study of cotton fiber quality improvement.

DETERMINATION OF THE FACTORS LIMITING COTTON FIBER QUALITY IN TURKEY

This study aims to determine the variation of fiber quality in cotton varieties produced in the Southeastern Anatolia Region and Sanliurfa, Diyarbakir provinces. 1090 fiber samples were obtained from 6 cotton varieties (Lima, Stoneville 468, Candia and Babylon for Sanliurfa, Lima, Stoneville 468, Lodos and Gloria for Diyarbakir) collected from ginning factories in Sanliurfa and Diyarbakir. Statistical analyzes were done with HVI device and obtained data were analyzed by using Excel and TOTEMSTAT programs. In the frequency distribution, cotton varieties of the region are in the medium and long fiber group in terms of fiber length. They were in the medium (only two samples), strong and very strong group in terms of fiber strength. They were generally in the medium and thick group in terms of fiber fineness (micronaire). In terms of fiber uniformity index, the majority of the fibers were in the middle group. In terms of short fiber index, most of the fibers were in the very low and low groups. The majority of the samples were in the high and medium group in terms of fiber elongation, in the mature and very mature group in terms of fiber maturity. In terms of spinning consistency index (SCI) 59,2% of the fibers were between 119,41 and 135,83; 31,3% of them, were between 135,83 and 152,24, 58,2% of the material has a reflectance value of 74 and above. All materials were in white and light-yellow groups in terms of yellowness. It has been observed that the majority of the fibers (66%) are in the low group in terms of trash count. The results obtained from the study of cotton produce of Southeastern Anatolia Region of Turkey has shown that good fiber quality and to meet the demand of textile industry.

Change Of Cotton Fiber Quality Indicators Under Technological Processes

In this article, the quality indicators of fiber under the influence of various technological processes of Sultan selection cotton were determined and the optimal variant of the technological process for production was recommended. Basic expressions tangled fiber, cortical fiber, knot, staple mass length, specific tensile strength, fiber maturity.

Effect of irrigation and planting geometry on cotton fiber quality and seed composition

Background: Cotton fiber quality and seed composition play vital roles in the economics of cotton production systems and cotton seed meal industry. The objective of this research was to examine the effects of different levels of irrigation and planting geometries on fiber quality and seed composition of cotton (Gossypium hirsutum L.). A two-year study was conducted in 2018 and 2019 on a Dundee silt loam soil in the Southeast USA with a warm and humid climate. Irrigation treatments were, irrigating every furrow (FI, full irrigation) and alternate furrow (HI, half irrigation), and no irrigation (RF, rainfed), and planting geometries were a single-row (SR) and twin-row (TR) on ridges spaced 102 cm apart. Fiber quality was tested by using the High-Volume Instrument (HVI) and Advanced Fiber Information Systems (AFIS). Seed protein, oil, and fiber were estimated using near-infrared reflectance spectroscopy. Results: The results showed irrigation and planting treatments played a significant role in fiber quality and seed composition. Across irrigation treatments, significant differences were seen in fiber properties, including micronaire, uniformity, upper half mean length (UHML), strength, yellowness, short fiber, upper quartile length (UQL), fineness, maturity ratio, and neps. The micronaire was negatively affected by irrigation as FI-SR, FI-TR, HI-SR, and HI-TR had recorded 11-12% over the RF-SR and TR treatments. The planting geometry played a minor role in determining fiber quality traits like micronaire and nep count. Irrigation treatments recorded significantly lower protein content by 3-4 % than rainfed, while oil content significantly increased by 6-10 %. Conclusions: The results of the study indicate a potential for improving cotton fiber and seed qualities by managing irrigation and planting geometries in cotton production systems in the Mississippi Delta region.

Management analysis of cotton-fiber quality in cotton gining plants

This article focuses on the analysis of management of quality of cotton fiber on the ginning enterprises of Uzbekistan in the conditions of export-oriented economy.

Use of Pressured-Air for Cotton Lint Cleaning

Saw-type lint cleaner (STLC) was most efficient lint cleaner in cotton ginning. However, STLC damaged fiber quality. An air-bar lint cleaner (ABLC) was developed and evaluated to preserve cotton fiber quality. The ABLC used pressurized-air to remove non-lint materials from cotton fiber. During lint cleaning process, non-lint materials attached to the fiber were blown off the fiber without the fiber making aggressive mechanical contact with a grid bar in conventional saw-type lint cleaner (STLC). It was expected using this concept that the fiber quality could be preserved by reducing the damage from mechanical impact of the fiber against the grid bar. Preliminary testing of the ABLC prototype showed that ABLC generated less lint waste and had a higher turnout rate than STLC. Use of ABLC could save 2.8 kg of lint in each 225 kg bale of cotton. The High Volume Instrument (HVI) analysis indicated the fiber properties in fiber length, uniformity, short fiber content, and color were not significantly different between ABLC and STLC. However, the Advanced Fiber Information System (AFIS) tests showed STLC had better performance than ABLC in fiber length and short fiber content while the trash and dust content with ABLC was lower than the STLC. More research was necessary to further prove the concept of ABLC and improve its performance in preserving cotton fiber quality.

Ramularia leaf spot effect on yield and fiber quality of cotton submitted to fungicide application

ABSTRACT Ramularia leaf spot (RLS) is the major cotton disease in Brazil and one of the main causes of crop yield reduction. The disease causes defoliation reduces photosynthetic capacity and causes premature opening of bolls. Due to the impact of RLS on the production of Brazilian cotton and the lack of scientific publications investigating the disease, the present work aims to evaluate the efficiency of fungicides in controlling disease and their impact on yield and fiber quality. Three field experiments were carried out during the 2014/2015 and 2016/2017 seasons in Planaltina, Federal District and Cristalina, Goiás. Experiments followed a randomized complete block design (4 blocks) and treatments consisted of the application of fungicides, plus a non-treated plot. The fungicide applications began preventively and were repeated every 14 days until six sprays had been completed. Severity of RLS was assessed and used to calculate the area under disease progress curve (AUDPC). Yield and cotton fiber quality were also evaluated. All fungicides had reduced AUDPC and obtained higher cotton yields in relation to the non-treated plot. Strobilurin-group fungicides (azoxystrobin, pyraclostrobin and picoxystrobin) showed low effectiveness when sprayed alone. The demethylation inhibitor fungicides (difenoconazole, epoxiconazol, tetraconazol and metconazole) were more effective than the strobilurins. The highest efficiency rates were achieved by application of pyraclostrobin + fluxapyroxad, pyraclostrobin + epoxiconazole + fluxapyroxad and fentin hydroxide. Disease severity affected cotton yield, causing losses from 14.8% to 31.7%. Resultant reductions in cotton fiber quality negatively affect the micronaire composition, altering the length, strength and uniformity of fibers.