Lint Fiber Research Articles

Increasing seed lint fiber density for promoting cotton yield: Opportunities and challenges

High seed lint fibre density is proposed as one of the breeding objectives for boosting cotton fibre yield. We identify the sources of potential lint fibre cells and discuss the opportunities and challenges involved in realizing the goal.

Investigation of Fourier transform infrared spectroscopy potential in cotton fiber micronaire measurement and distribution

Cotton micronaire is an essential fiber quality attribute that characterizes both fiber maturity and fineness components. Micronaire and other attributes are measured on fiber lint routinely in laboratories under controlled environmental conditions following a well-established high-volume instrument protocol. In this study, the attenuated total reflection Fourier transform infrared spectroscopy, characterizing fundamental group vibrations in fiber cellulose from 4000 to 400 cm−1, and using an attenuated total reflection device, was explored for fiber micronaire assessment, especially for seed cotton locule fibers that were mingled with nonlint materials, and varied in fiber maturity within a naturally variable sample. Partial least squares multivariate regression models and the algorithmic infrared maturity approach were developed and then applied to predict micronaire values of validation samples and independent seed cotton samples for comparison. Unlike partial least squares models that showed worse in the coefficient of determination, bias, and percentage of samples within the 95% agreement range for independent samples than for validation samples, the algorithmic infrared maturity approach indicated a similarity in the coefficient of determination, bias, and percentage of samples within the 95% agreement range between the validation samples and independent samples. In particular, the algorithmic infrared maturity approach avoided the need to re-calibrate the model with new samples. Therefore, the development of a robust and effective Fourier transform infrared technique combined with the infrared maturity approach for rapid laboratory micronaire assessment and distribution demonstrated a great potential for its extension to the early micronaire testing in remote/breeding locations, and also to regular cotton fibers, processed cotton yarns and fabrics.

Determination of fiber yield and quality in cotton cultivars, applied with biologically reclaimed greywater

Application of recycled municipal wastewater and industrial effluents using biological treatment methods to industrial crops is an ingenious practice to ensure the combined means of adopting sustainable industrial crops production through sustainable freshwater management. An investigation was made to study the effects of recycled greywater treated using the extended form of Effective Microorganisms in the sewage treatment plant, over the growth, biochemical contents, yield and fiber quality of MCU7 and SVPR2 cotton cultivars, grown under experimental conditions. The efficacy of the recycled greywater treatment was compared with ground well water as control and untreated greywater as on another treatment. Improved yield of lint fiber and cotton seeds were obtained with a ginning out turn (GOT) of 71.66% and 66.1% in the SVPR2 and MCU7 cultivars, respectively, when irrigated with recycled greywater. Similarly, both the cotton cultivars, supplied with the recycled greywater was found with a significantly higher (P ≤ 0.01) stable length (SL) and fiber strength, as well as significantly higher spinning consistency index (SCI) (P ≤ 0.05) and uniformity ratio, when compared with the other two treatments. The novelty approach, adopted in the experiment therefore can be concluded using the recycled greywater to the specific cotton cultivars in water-deficit agro-climatic conditions would be beneficial to sustain the cotton production, would be in turn benefiting the industries.

Inter-Specific Hybridization in Cotton (Gossypium hirsutum) for Crop Improvement

Interspecific hybridization has contributed significantly to land diversity, species evolution, and crops’ domestication, including upland cotton, the cultivated form of Gossypium hirsutum. Being the world’s most important fiber crop species, Gossypium hirsutum belongs to the allotetraploid Gossypium consisting of six additional tetraploid species. The lint fiber evolved once in diploid parent A-genome species in the Gossypium’s history and passed on during hybridization of the A-genome with the D-genome and was maintained in subsequent evolution. The domestication history of G. hirsutum involved the collection and use of lint fibers by indigenous people for the purpose of making strings and other textile products; hence, spinnable lint fibers were likely to have evolved under domestication. Crossing with G. barbadense has resulted in the development of multiple genetic lines in contemporary upland cotton. However, in later-generation hybrids between G. hirsutum and other polyploid species, reproductive barriers such as reduced fertility, segregation distortion, and hybrid breakdown are frequently observed, complicating the task of introgressing new, stably inherited allelic variation from inter-specific hybridization. Recent efforts in molecular genetics research have provided insights into the location and effects of QTLs from wild species that are associated with traits important to cotton production. These and future research efforts will undoubtedly provide the tools that can be utilized by plant breeders to access novel genes from wild and domesticated allotetraploid Gossypium for upland cotton improvement.

Single-cell RNA-seq reveals fate determination control of an individual fibre cell initiation in cotton (Gossypium hirsutum).

Cotton fibre is a unicellular seed trichome, and lint fibre initials per seed as a factor determines fibre yield. However, the mechanisms controlling fibre initiation from ovule epidermis are not understood well enough. Here, with single-cell RNA sequencing (scRNA-seq), a total of 14 535 cells were identified from cotton ovule outer integument of Xu142_LF line at four developmental stages (1.5, 1, 0.5 days before anthesis and the day of anthesis). Three major cell types, fibre, non-fibre epidermis and outer pigment layer were identified and then verified by RNA in situ hybridization. A comparative analysis on scRNA-seq data between Xu142 and its fibreless mutant Xu142 fl further confirmed fibre cluster definition. The developmental trajectory of fibre cell was reconstructed, and fibre cell was identified differentiated at 1 day before anthesis. Gene regulatory networks at four stages revealed the spatiotemporal pattern of core transcription factors, and MYB25-like and HOX3 were demonstrated played key roles as commanders in fibre differentiation and tip-biased diffuse growth respectively. A model for early development of a single fibre cell was proposed here, which sheds light on further deciphering mechanism of plant trichome and the improvement of cotton fibre yield.

A deletion/duplication in the Ligon lintless-2 locus induces siRNAs that inhibit cotton fiber cell elongation.

Most cultivated cotton (Gossypium hirsutum L.) varieties have two types of seed fibers: short fuzz fiber strongly adhered to the seed coat, and long lint fiber used in the textile industry. The Ligon lintless-2 (Li2) cotton mutant has a normal vegetative phenotype but produces very short lint fiber on the seeds. The Li2 mutation is controlled by a single dominant gene. We discovered a large structural rearrangement at the end of chromosome D13 in the Li2 mutant based on whole-genome sequencing and genetic mapping of segregating populations. The rearrangement contains a 177-kb deletion and a 221-kb duplication positioned as a tandem inverted repeat. The gene Gh_D13G2437 is located at the junction of the inverted repeat in the duplicated region. During transcription such structure spontaneously forms self-complementary hairpin RNA of Gh_D13G2437 followed by production of small interfering RNA (siRNA). Gh_D13G2437 encodes a Ran-Binding Protein 1 (RanBP1) that preferentially expresses during cotton fiber elongation. The abundance of siRNA produced from Gh_D13G2437 reciprocally corresponds with the abundance of highly homologous (68%-98% amino acid sequence identity) RanBP1 family transcripts during fiber elongation, resulting in a shorter fiber phenotype in the Li2. Overexpression of Gh_D13G2437 in the Li2 mutant recovered the long lint fiber phenotype. Taken together, our findings revealed that siRNA-induced silencing of a family of RanBP1s inhibit elongation of cotton fiber cells in the Li2 mutant.

Identification of AtSND1 homologous NAC genes related to cotton fiber development, in silico analyses, and gene expression patterns

AbstractBecause cotton is the most important fiber crop, the differentiation and development mechanism of cotton fiber cells has been a hot topic in cotton research. NAC (for NAM, ATAF, and CUC2) is a class of plant‐specific transcription factor families that regulate multiple aspects of plant growth and development. Previously, we identified 33 differentially expressed NAC genes in upland cotton based on fiber‐related transcriptome profiling. In this study, we conducted chromosome localization, systematic evolution, and gene structural analysis of 242 NAC genes genome‐wide based on a high‐quality reference genome of upland cotton. In addition, the expression pattern analysis of 16 differentially expressed GhNACs was carried out by RT–PCR using ovules at early fiber initiation stages of n2 recessive naked seed mutant (n2NSM) and Xuzhou142 fuzzless–lintless mutant (Xu142fl). The results showed that GhNAC230 and GhNAC115 were most closely related to AtSND1 and downregulated in ovules of Xu142fl compared with n2NSM. Quantitative RT–PCR (qRT–PCR) analysis of GhNAC230 demonstrated its gradual accumulation from −1 days postanthesis (DPA) to 1 DPA in n2NSM and further confirmed its downregulated expression in 1 DPA ovules of Xu142fl compared to n2NSM. The current study predicted a pair of NAC genes that might be key candidate genes that are crucial for lint fiber development.

Comparative transcriptome analysis uncovers cell wall reorganization and repressed cell division during cotton fiber initiation

BackgroundTetraploid cotton plants serve as prime natural fiber source for the textile industry. Although various omics studies have revealed molecular basis for fiber development, a better understanding of transcriptional regulation mechanism regulating lint fiber initiation is necessary to meet global natural fiber demand.ResultsHere, we aimed to perform transcriptome sequencing to identify DEGs (differentially expressed genes) in ovules of the cotton variety Xu142 and its fibreless mutant Xu142fl during early lint fiber initiation period. Totally, 5516 DEGs including 1840 upregulated and 3676 downregulated were identified. GO enrichment analysis revealed that the downregulated DEGs were mainly associated with biological processes such as transcription related biosynthesis and metabolism, organic cyclic compound biosynthesis and metabolism, photosynthesis, and plant cell wall organization, with molecular functions involving transcription related binding, organic cyclic compound binding, and dioxygenase activity, while the upregulated DEGs were associated with DNA replication and phospholipid biosynthetic related processes. Among the 490 DEGs annotated as transcription factor genes, 86.5% were downregulated in the mutant including the Malvaceae-specific MMLs, expression patterns of which were confirmed during the central period of lint fiber initiation. Investigation of the 16 genes enriched in the cell wall organization revealed that 15 were EXPA coding genes.ConclusionsOverall, our data indicate that lint fiber initiation is a complicated process involving cooperation of multiple transcription factor families, which might ultimately lead to the reorganization of the cell wall and terminated cell division of the differentiating fiber initials.

Breeding assessment of new promising cotton lines

Abstract. Cotton breeding in Bulgaria is mainly aimed at improving the earliness, productivity and fiber quality of modern varieties. The creation of new genetic diversity is one of the basic prerequisites for the success of breeding programs. The aim of the study was to evaluate cotton lines obtained by intraspecific and remote hybridization combined with backcross technology, with a view to their most effective usage in selection. Twenty-three lines were included in competitive variety trials conducted during the 2014-2017 period. The averaged results showed that lines 550, 639, 641, obtained by remote hybridization, appeared to be very promising. These three lines were distinguished by the best combination of productivity, fiber length and fiber lint percentage, and by these three indicators they exceeded the standard variety Chirpan-539. A new cotton variety Aida (No. 457) was approved, which in seed cotton yield and fiber yield, and technological fiber properties surpassed the standard varieties Chirpan-539 for earliness and productivity and Avangard-264 for fiber quality. The candidate variety 535 continued the state variety testing. Two new candidate cotton varieties No. 550 and No. 553 were released. In the state variety testing the three candidate varieties confirmed their qualities. The obtained lines, distinguished by one trait or by a complex of qualities, enriched the gene pool of Bulgarian cotton.

Elucidation of sequence polymorphism in fuzzless-seed cotton lines.

Most commercially produced cotton cultivars have two types of fibers on the seed coat, short fuzz and long lint. Lint fiber is used in the textile industry, while fuzz is considered an undesirable trait. Both types of fibers are believed to be controlled by the same regulators; however, their mechanisms of actions are still obscure. Cotton fiber mutants provide an excellent system to study the genes that regulate fiber development. Here we described four uncharacterized and three previously reported cotton mutants with fuzzless seed phenotypes. To evaluate whether or not the genes previously associated with fuzzless seed phenotypes have mutations we sequenced whole genomic DNA of seven mutants and wild type varieties. We identified multiple polymorphic changes among the tested genes. Non-synonymous SNPs in the coding region of the MML3-A gene was common in the six mutant lines tested in this study, showing both dominant and recessive fuzzless phenotypes. We have mapped the locus of the causative mutation for one of the uncharacterized fuzzless lines using an F2 population that originated from a cross between the dominant fuzzless mutant and a wild type. Further, we have clarified the current knowledge about the causative n2 mutations by analyzing the sequence data and previously reported mapping data. The key genes and possible mechanisms of fiber differentiation are discussed in this study.

Improved lint yield under field conditions in cotton over-expressing transcription factors regulating fibre initiation.

Only a few transcription factors (TFs) regulating which cells of the ovule epidermis differentiate into lint fibres have been identified in cotton (Gossypium hirsutum L.). In this study, the effect on lint yield and fibre quality of over-expressing three TFs in cotton, GhHD-1, GhMYB25 and GhMYB25Like, and their double and triple combinations, were evaluated in field experiments over two seasons. The expression of single or stacked TFs were all driven either by an ovule-specific promoter, FBP 7, or a constitutive promoter, Stunt 7, in a Coker 315 background. TF type, either singly or in combination, was found to be the most significant factor affecting lint yield. Among 64 transgenic lines tested, seven were higher yielding than null segregant lines in one or both seasons and were all from the sets with single and double over-expressed TF combinations. A reduced yield was associated with the set of triple combinations. The two most stable high yielding lines across the seasons recorded 12-22% higher yields than the nulls, although were not competitive to locally adapted commercial controls. Over-expression of TFs singly or in combination did not significantly alter fibre length and strength, but sometimes increased fibre micronaire. There were positive relationships between lint yield and lint percentage and lint yield and fibre density amongst the transgenic lines. Our preliminary results suggest that manipulating TF expression, either singly or in pairs, can increase the density of fibres initiated on developing seeds and fibre yields under field conditions while maintaining overall fibre quality.

Membrane lipid raft organization during cotton fiber development

BackgroundCotton fiber is a single-celled seed trichome that originates from the ovule epidermis. It is an excellent model for studying cell elongation. Along with the elongation of cotton fiber cell, the plasma membrane is also extremely expanded. Despite progress in understanding cotton fiber cell elongation, knowledge regarding the relationship of plasma membrane in cotton fiber cell development remains elusive.MethodsThe plasma membrane of cotton fiber cells was marked with a low toxic fluorescent dye, di-4-ANEPPDHQ, at different stages of development. Fluorescence images were obtained using a confocal laser scanning microscopy. Subsequently, we investigated the relationship between lipid raft activity and cotton fiber development by calculating generalized polarization (GP values) and dual-channel ratio imaging.ResultsWe demonstrated that the optimum dyeing conditions were treatment with 3 μmol·L− 1 di-4-ANEPPDHQ for 5 min at room temperature, and the optimal fluorescence images were obtained with 488 nm excitation and 500–580 nm and 620–720 nm dual channel emission. First, we examined lipid raft organization in the course of fiber development. The GP values were high in the fiber elongation stage (5–10 DPA, days past anthesis) and relatively low in the initial (0 DPA), secondary cell wall synthesis (20 DPA), and stable synthesis (30 DPA) stages. The GP value peaked in the 10 DPA fiber, and the value in 30 DPA fiber was the lowest. Furthermore, we examined the differences in lipid raft activity in fiber cells between the short fiber cotton mutant, Li-1, and its wild-type. The GP values of the Li-1 mutant fiber were lower than those of the wild type fiber at the elongation stage, and the GP values of 10 DPA fibers were lower than those of 5 DPA fibers in the Li-1 mutant.ConclusionsWe established a system for examining membrane lipid raft activity in cotton fiber cells. We verified that lipid raft activity exhibited a low-high-low change regularity during the development of cotton fiber cell, and the pattern was disrupted in the short lint fiber Li-1 mutant, suggesting that membrane lipid order and lipid raft activity are closely linked to fiber cell development.

Recurrent intraocular inflammation after cataract surgery associated with retained lint fiber

A 65-year-old woman had manual small-incision cataract surgery. Postoperatively, she developed 2 episodes of significant postoperative intraocular inflammation involving the anterior chamber and vitreous. The vitreous biopsy was negative for infectious etiology in both episodes. She later was found to have a retained lint fiber in the eye located over the posterior capsule. After removing the fiber, there was no recurrence of the inflammation. This case report suggested that retained lint, most often cotton fiber, which is introduced into the eye during cataract surgery, may be associated with postoperative intraocular inflammation. Therefore, measures should be taken before and during surgery to avoid the fibers entering the eye.

Genetic Identification and Transcriptome Analysis of Lintless and Fuzzless Traits in Gossypium arboreum L.

Cotton fibres, as single cells arising from the seed coat, can be classified as lint and fuzz according to their final length. Gossypium arboreum is a cultivated diploid cotton species and a potential donor of the A subgenome of the more widely grown tetraploid cottons. In this study, we performed genetic studies on one lintless and seven fuzzless G. arboreum accessions. Through association and genetic linkage analyses, a recessive locus on Chr06 containing GaHD-1 was found to be the likely gene underlying the lintless trait. GaHD-1 carried a mutation at a splicing acceptor site that resulted in alternative splicing and a deletion of 247 amino acid from the protein. The regions containing GaGIR1 and GaMYB25-like were found to be associated with fuzz development in G. arboreum, with the former being the major contributor. Comparative transcriptome analyses using 0-5 days post-anthesis (dpa) ovules from lintless, fuzzless, and normal fuzzy seed G. arboreum accessions revealed gene modules and hub genes potentially important for lint and fuzz initiation and development. Three significant modules and 26 hub genes associated with lint fibre initiation were detected by weighted gene co-expression network analysis. Similar analyses identified three vital modules and 10 hub genes to be associated with fuzz development. The findings in this study contribute to understanding the complex molecular mechanism(s) regulating fibre initiation and development and indicate that G. arboreum may have fibre developmental pathways different from tetraploid cotton. It also provides candidate genes for further investigation into modifying fibre development in G. arboreum.

The Ligon lintless -2 Short Fiber Mutation Is Located within a Terminal Deletion of Chromosome 18 in Cotton.

Extreme elongation distinguishes about one-fourth of cotton (Gossypium sp.) seed epidermal cells as "lint" fibers, useful for the textile industry, from "fuzz" fibers (<5 mm). Ligon lintless-2 (Li 2 ), a dominant mutation that results in no lint fiber but normal fuzz fiber, offers insight into pathways and mechanisms that differentiate spinnable cotton from its progenitors. A genetic map developed using 1,545 F2 plants showed that marker CISP15 was 0.4 cM from Li 2 , and "dominant" simple sequence repeat (SSR) markers (i.e. with null alleles in the Li 2 genotype) SSR7 and SSR18 showed complete linkage with Li 2 Nonrandom distribution of markers with null alleles suggests that the Li 2 phenotype results from a 176- to 221-kb deletion of the terminal region of chromosome 18 that may have been masked in prior pooled-sample mapping strategies. The deletion includes 10 genes with putative roles in fiber development. Two Glycosyltransferase Family 1 genes showed striking expression differences during elongation of wild-type versus Li 2 fiber, and virus-induced silencing of these genes in the wild type induced Li 2 -like phenotypes. Further, at least 7 of the 10 putative fiber development genes in the deletion region showed higher expression in the wild type than in Li 2 mutants during fiber development stages, suggesting coordinated regulation of processes in cell wall development and cell elongation, consistent with the hypothesis that some fiber-related quantitative trait loci comprise closely spaced groups of functionally diverse but coordinately regulated genes.

Analysis of differentially expressed genes and fiber development in &amp;lt;italic&amp;gt;Gossypium arboreum&amp;lt;/italic&amp;gt; fuzzless mutant

<p indent="0mm">Cotton fiber, one of main nature textile and longest single cell, is a good material for researching the cotton fiber development. In this study, fuzz mutant (FZ) and wild-type (<italic>fz</italic>) which belong to diploid <italic>Gossypium arboreum </italic>species were used for unraveling molecular mechanism of fuzz fiber initiation by scanning electron microscopy (SEM), paraffin section and RNA sequencing technology. It was found that any fibers scarcely initiated on the ovule surface of the mutant at 0DPA, compared with that of the wild-type. Only lint fiber cells emerged on the ovule surface of fuzz mutant, while abundant fuzz and lint fiber cells appeared in wild-type at +3DPA stage. The transcriptome analysis of FZ and<italic> fz</italic> across the four fiber development stages (0DPA, +3DPA, +5DPA, and +8DPA) indicated that the number of differentially expressed gene was 3780. There were litter differentially expressed genes at 0DPA in FZ and <italic>fz</italic>. In the proceed of ovule development, the number of differentially expressed genes was increased gradually. The KEGG enriched pathway analysis illustrated that these differentially expressed genes were involved in cutin, suberine and wax biosynthesis, phenylalanine metabolism pathways and plant hormone signal transduction pathways. The analysis of co-expressed gene trend lines indicated that the up-regulated genes in mutant at +3DPA were all involved in metal ion binding, MAPK cascade, oxidoreductase activity and transcription regulation, resulting in failed fuzz fiber cells initiation in mutant. These findings elaborated a dynamic variation about fuzz fiber initiation in diploid <italic>G. arboreum</italic>, which provides a reference for further research in the cotton fiber development.

Genetics of the fuzzless ovule phenotype of Gossypium arboreum accession PI 615733 (cv. Zi-Hua Guang Zi)

Abstract Lint and fuzz are the two types of fiber that develop on cotton seeds. Lint is an economically important fiber used in the textile industry. Fuzz fibers remain attached to seeds, and reducing the amount of fuzz could improve ginning efficiency. The Gossypium arboreum accession PI 615733 from the United States Department of Agriculture cotton germplasm collection showed the fuzzless trait, where no fuzz fibers were observed on seeds. Accession PI 615733 was crossed with the fuzzy seeded G. arboreum accession PI 529729 to develop an F2 population. Seeds from F1 plants showed no fuzz fiber. For the F2 population of 409 plants, 239 plants were classified as fuzzless and 170 were classified as fuzzy. These data support a two-gene model with incomplete dominance. A greater understanding of the genetic mechanisms controlling fiber development on cotton seeds could contribute to breeding efforts to improve lint fiber yields and quality.

Promotion of growth, yield and fiber quality attributes of Egyptian cotton by bacillus strains in combination with mineral fertilizers

Implementation of proper management practices using biological approaches is important to maintain soil quality and cotton yield in sandy desert soils of Egypt. This experiment was conducted at the Agriculture Experimental farm, Kafer El-Sheikh governorate, Cotton Research Institute of Egypt during 2016–2017 seasons to study the effect of inoculation with bacterial strains of Bacillus circulance (BC) and Bacillus megatherium (BM) and their co-inoculation in combinations with 50% and 100% of recommended dose fertilization (RDF) on growth, yield, and fiber properties of Egyptian cotton Giza-94. Results showed that all important morphological attributes of cotton such as plant growth, number of fruit sympodial branches, number of bolls per plant, boll weight, lint cotton yield and fiber properties significantly increased with the increase rate of RDF, and inoculation of cotton seeds with the bacterial strains exerted additive effects. The highest increase of cotton yield was observed at the combined use of bacterial strains BC + BM with 50% RDF followed by BC + BM with 100% RDF treatment which attributed on the cotton yield increase by 33% and 15% compared to the respective control. The application of Bacillus strains as a biofertilizer could be an alternative option to reduce considerable amounts of chemical fertilizers input by enhancing nutrient use efficiency (NUE) and, thereby, improves cotton productivity.

Qualitative Assessment of Reaction Norm of New Cotton Lines (G. hirsutum L.)

The qualitative side of reaction norm of eight promising cotton lines and of standard cultivar was studied. The lines were obtained by intra-specific and remote hybridization of the G. hirsutum L. species with some wild diploid species of the genus Gossypium L. The type of their dynamic regression (of their regression curve) and the structure of ecological environments in their dynamic rows were determined in order to characterize the reaction norm. The years of the study (2014-2017) appeared to be as different ecological environments. Four qualitative characters - seed cotton yield, boll weight, fiber length and fiber lint percentage were analyzed. It was found that in most cases the studied lines had reaction norm which considerably differed from that of the standard cultivar. The specificity of the lines reaction was less pronounced in its type (in ½ of cases) and stronger (in more than 7/8 of cases) in the structure of ecological environments in its dynamic row. By the index type of reaction line № 457 was closest to the standard cultivar, while line № 449 was furthest from it. For the individual characters, the line reaction norm was manifested to varying degrees, from very high - for the boll weight, where similarity with the standard cultivar was missing, to average - for the seed cotton yield, where for this character half of the lines were similar to the standard cultivar.

Evaluation of New Cotton Linesin View of Selection

The selection value of 8 new cotton lines and the standard variety was studied on the base of significant differences between the most important agronomic characters and their phenotypic stability, over a four-year period 2014-2017. The years of the investigation appeared to be as different ecological environments. Four stability parameters - bi (Finlay and Wilkinson, 1963), σ2i and S2i (Shukla, 1972) and YSi (Kang, 1993) were used. It was found that the studied cotton lines interacted significantly with the environmental conditions (years) in terms of total yield, boll weigt, fiber length and lint persentage. All lines had bigger breeding value than the standard cultivar Chirpan-539 exceeding it by one or more traits. In a complex assessment as best line for the studied period outlined No. 550 distinguished by 9.7% higher yield than the standard, 0.4 mm longer fiber and 1.2% higher lint percentage. This line showed stability for the ball weight and fiber length, and responsiveness above the average to the environmental conditions for the seed cotton yield and lint percentage, but both traits were with low stability. Lines Nos. 553 and 426 showed a high average level and high stability for yield, Nos. 489 and 535 – for ball weight, No. 553 – for fiber lint percentage and No. 489 – for fiber length, which makes them very valuable for the selection of these traits. A complex breeding value (average level and stability) for all studied traits was found for line No. 553.