Introduction

The global importance of cotton as a prominent natural fiber source in the textile industry has not diminished over the decades (Yu et al. 2014, 2021; Zheng et al. 2023).

The textile industry requires a tireless search for high-quality cotton fibers to produce threads, fabrics, and clothing. Therefore, choosing the suitable raw material is essential to ensure the production of high-quality and globally competitive textile materials. Numerous factors, from fiber strength and length to properties such as maturity, fineness, micronaire, and uniformity, among others, are fundamental to determining the quality of cotton fibers (Cotton Incorporated, 2018; INIA, 2012; Siddiqui et al., 2020). The selection and choice of cotton cultivars with high yield potential and extensive applications can affect the economic viability of farmers and the quality of textile products (Barella et al., 1985; Serquen-Lopez et al., 2019; Siddiqui et al., 2020).

The genus Gossypium is characterized by its incredible biodiversity and encompasses multiple species that are widely adaptable to different climatic environments and geographic conditions (Weiskopf et al., 2020). This adaptation results in fibers with particular characteristics and different lengths and strength classes, which adds an extra level of complexity and opportunity for the textile industry (Zhou et al., 2022; Johnson et al., 2022; Wang et al., 2023).

In the specific case of cotton native to the Amazon region of Peru, indigenous communities meticulously protecting of textile techniques inherited from previous generations (Morales-Aranibar et al., 2023). These techniques have gone beyond simple manufacturing and entered a universe that combines art, tradition, and sustainability. Currently, cotton fibers native to Peru have been used and processed on traditional handlooms (Morales-Aranibar et al., 2023; Cardoso et al., 2023; Vasquez et al., 2023). This approach improves the physical properties of textile products and has great cultural and historical significance (Ali et al., 2023).

Gossypium barbadense L. var. brasiliensis is genetically valuable due to its adaptability to humid environments and unique textile properties. This species of plant has unique characteristics because its seeds are fused together into somewhat kidney-shaped masses; this characteristic has led to its identification as “kidney seed cotton” (Lazo, 2012; MINAM, 2020; Morales-Aranibar et al., 2023). Its fiber length is comparable to that of Tangüis cotton, and its strength is similar to that of American Pima cotton, although the density of the fiber limits certain applications. This cotton plant is ideal for the manufacture of resistant textiles such as uniforms, military clothing, and footwear (Lazo, 2012; MINAM, 2020).

In previous studies, this species was recognized as G. barbadense variety brasiliensis. It was initially discovered in anonymous samples of cotton of Amazonian origin and with white fibers and developed in the regions of Rupa Rupa and Omagua in Peru (MINAM, 2014, 2017, 2020; Basurto, 2005). Current investigations have confirmed that this species is found in the forest areas of Cusco in the province of La Convención, highlighting its adaptability to the specific environmental conditions of the region since this accession was found in all Amazonian communities in Peru sampled by Morales-Aranibar et al. (2023); however, the origin of this Amazonian cotton remains unknown. Some researchers explained that this cotton plant was moved to the western region of the Andes through Apure River, located in northwest Colombia; however, there is currently no information confirming its center of origin. More studies in Marañón River basin are important for deciphering this origin. These studies will be able to confirm their origin or confirm whether they are intermediate variants between the types of cotton found on both sides of the Andes Mountains (MINAM, 2020; Ano et al., 1984).

One of the biggest challenges for the cultivation of G. barbadense var. brasiliensis is the limited genetic diversity of cultivated cultivars, which restricts opportunities for significant advances in plant genetic improvement (Viot, 2016; Él, et al. 2021). However, there is a promising source of solutions: native or wild germplasm from Peru. This promising source has a valuable genetic bank that can be fundamental for enhancing the adaptation of plants to adverse climatic conditions, in addition to improving other desired agronomic characteristics (Viot, 2016; Ma et al., 2021). The high genetic potential of this cotton species has not yet been explored in relation to plant genetic improvement strategies. In this way, the proposed approach could significantly contribute to mitigating the current challenges faced by the cotton textile industry.

Recent findings by Morales-Aranibar et al. (2023) revealed the presence of G. barbadense var. brasiliensis in different native communities in the districts of Echarati and Megantoni in the province of La Convención, Cusco, Perú. These findings reinforce the urgency of intensifying genetic exploration of the unique fiber characteristics of these native cotton accessions, especially because commercial cultivars are losing their fiber bundle strength characteristics (Hinze et al., 2016; Li et al., 2017; Peixoto et al., 2022; Morales-Aranibar et al., 2024). Therefore, conserving and studying these native germplasms has become a priority, especially given recent biotechnological advances and the optimized management of genetic resources (Viot, 2016; Smith et al., 2024).

The objective of this research was to decipher the quality of the white fiber of Gossypium barbadense var. brasiliensis in the province of La Convención, Cusco, Perú, as well as to evaluate other critical aspects of these native cotton accessions. The results could be relevant to the scientific community, farmers, and the textile industry, as they could provide valuable genetic resources for the development of new varieties and cultivation methods, thus influencing important decisions in cotton conservation, research, and production.

Methods

Study sites and sampling methods

Field sampling was carried out within the Amazonian biodiversity belonging to the province of La Convención, located in the region of Cusco, Perú. Samples of white cotton fiber were collected from the native Amazonian communities of Chakopishiato, Poyentimari, and Koribeni in the Echarati district and from the communities of Miaria, Kirigueti, Timpía, Sensa, Ticumpinía and Camisea, Shivankoreni and Nuevo Mundo in the Megantoni district. The coordinates for these locations are 12°46'3.18"S and 72°34'36.70"W, at and altitude of 1137 m a.s.l. in the Echarati District, and 11°43'3.13"S and 72°56'40.68"W, at and altitude of 334 m a.s.l. in Megantoni District.

The collection and analysis phases extended from April to December 2021. To collect samples of cotton (Gossypium barbadense L. var. brasiliensis), consent was obtained in advance from the owners of the plots. The collection methodology and identification of samples were performed according to the standardized procedures recommended by Manco-Céspedes et al. (2022), the Ministerio del Ambiente (MINAM, 2020), and the International Union for the Protection of New Varieties of Plants (UPOV, 2018), complemented with guidelines established by Morales-Aranibar et al. (2023).

The samples analyzed were limited to portions of white cotton fibers intentionally selected through non-probability sampling for accessibility or convenience. The reflectance/+b associated with the color was verified in all samples, with values ranging from 7.5 to 21.8. (data not shown). All cotton fiber samples were hand ginned. This approach is justified by the specificity of the study and the need to focus on native Peruvian communities strategically distributed in the districts of Echarati and Megantoni. The selected samples were chosen using the white color of their fibers as a criterion and when collected in the field, phenotypic variations were detected, which are shown in Table 1. Variations were evident in relation to the flower, seeds, bracts, capsules and leaves, and were summarized in Table 1 using 13 descriptors.

Table 1 Phenotypic information obtained when characterizing 18 white cotton samples collected from native Amazonian communities in La Convención, Cusco, Perú
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Measurement of descriptors

The cotton accessions collected included 16 genotypes of G. barbadense L. var. brasiliensis and two genotypes of Gossypium spp. These two cotton accessions without classification at species level (information that must be obtained from molecular studies), among the eight unknown cotton accessions collected by Morales-Aranibar et al. (2023), were selected for the white color of their fibers. In addition to this characteristic used as a premise in this study (fiber color), we also consider that these two unknown cotton accessions have attributes such as flower length, bract length, bract width, capsule width, length and width of the leaf that differentiate these accessions from the other species initially collected in the study by Morales-Aranibar et al. (2023). A portion of the fiber samples from each of the 18 cotton accessions were used to determine the descriptors described in Table 2.

Table 2 Qualitative and quantitative descriptors used in the characterization of white cotton samples collected from native Amazonian communities in La Convención, Cusco, Perú
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Fiber quality analyses of all cotton fiber samples were performed using the Uster® HVI (High Volume Instrument) M-1000 equipment under controlled conditions (20 °C and 65% relative humidity) in the Textile Laboratory FILASUR S.A. This laboratory is accredited by the Global Organic Textile Standard (GOTS), Global Recycle Standard (GRS), Better Cotton Initiative (BCI), World’s Finest Cottons (SUPIMA), Peruvian Pima (The world’s softest cotton). A sample of 50 g fibers from each of the native cotton accessions was used. For each fiber sample, the following quantitative descriptors were evaluated: fiber length (mm), micronaire index (maturation and fineness), fiber strength (gf·tex-1), length uniformity index (%), fiber elongation (%), maturation index (%) and short fiber index (%).

Statistical analysis

A comparison of the quantitative and qualitative descriptors was carried out considering two groups formed by different cotton species: the first group included two cotton accessions not yet characterized in terms of species [Gossypium spp. (unknown cotton)], and the second group included 16 native accessions of Gossypium barbadense L. var. brasiliensis. The quantitative data were subjected to analysis of variance considering the two groups of cotton species as unbalanced treatments, and the means were compared using the Tukey test at 5% probability. The quantitative data were also subjected to multivariate analysis using the principal component analysis (PCA) method to verify the general variability of the two sets of individuals and combined data for the groups formed, as well as the trends of the groupings and descriptors. The graphs were created using the software Rbio (Bhering, 2017), SigmaPlot 10.0® (Systat Software Inc.), R (R Core Team, 2014), and the “GGally” statistical package.

Results

According to a previous study by Morales-Aranibar et al. (2023), native communities of the Amazon in La Convención, Cusco, Perú, have maintained specific genetic varieties of cotton. However, the quality of the fibers of these varieties has not yet been explored in detail, which is crucial for evaluating whether certain genotypes could be especially valuable when evaluating and characterizing their particularities according to current international standards.

Figure 1 shows the details of branches, leaves, flower, lint, and seeds of the two genotypes belonging to Group 1 (Gossypium spp.) collected in Koribeni (Fig. 1A and B) and Poyentimari (Fig. 1C and D) in comparison with a specimen of Gossypium barbadense L. var. brasilensis (Group 2) collected in Nuevo mundo (Fig. 1E and F). The figure represents the variations that were found in relation to the collection data obtained at the time of collection and phenotypic identification initially established (Table 1).

Fig. 1
figure 1

Botanical material of Gossipium collected in Amazonian communities in Peru. A, B Gossypium spp. 1 species unidentified; (C, D) Gossypium spp. 2 species without identification; and (E, F) Gossypium barbadense L. var. brasilensis

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Qualitative characteristics of cotton fibers

Qualitative assessments were performed based on seven fiber quality properties for a total of 18 cotton accessions collected in the Amazon region of Cusco, Peru (Table 3). In the fiber samples of Gossypium spp., exceptional characteristics were observed in terms of fiber length (classified as long), fineness (very coarse), and high strength and elongation, which suggested that these two cotton accessions have high-quality fibers that are suitable for high-yield manufacturing of textile products. These two accessions also had a low short fiber content and high uniformity, and good fiber maturation. In contrast, fiber samples from G. barbadense L. var. brasiliensis have a wide range of qualitative characteristics, with fibers of medium length and wide variation in strength and uniformity (Table 3). However, the consistency of high strength and elongation across many sampling locations suggests inherent robustness and promising genetic diversity for future use in cotton breeding programs. The varied occurrence of short fibers and maturity indices reflect the complexity of the character and the variations it can manifest depending on adaptability to different locations and the fiber quality that could be exploited to develop superior varieties.

Table 3 Qualitative properties determined using the HVI method on 18 white fiber cotton accession samples collected from native Amazonian communities in La Convención, Cusco, Perú
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This analysis highlights the importance of strategic genotype selection and conservation for plant genetic improvement, demonstrating the need for additional investigations to fully understand the agronomic and textile potential of these cotton accessions. The variability observed in G. barbadense L. var. brasiliensis highlights the potential of this species to contribute to cotton biodiversity and crop resilience, as well as to satisfy the specific demands of the textile industry in terms of fiber quality and production sustainability.

Quantitative characteristics of the cotton fibers

The comparison of the quantitative characteristics of fibers from the 18 cotton accessions grouped into two groups [Gossypium spp. (group 1) and G. barbadense var. brasiliensis (group 2)] is shown in Table 4. The results showed that group 1, represented by the two Gossypium spp. accessions, had longer staple lengths (17%), greater fiber strengths (35%), and greater length uniformity indices (6%) than did group 2, represented by G. barbadense L. var. brasiliensis. For the other fiber quality characteristics, there was no significant difference between the two groups of cotton accessions (Table 4).

Table 4 Average values of quantitative fiber characteristics for Gossypium spp. accessions (Group 1) and G. barbadense L. var. brasiliensis accessions (Group 2) collected from native Amazonian communities in La Convención, Cusco, Perú
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Canonical variable analysis of the quantitative data revealed that this multivariate analysis was able to retain 100% of the data variability, with differentiation between groups of cotton accessions (Fig. 2). Group 1 accessions exhibited the highest values of staple length, micronaire index, fiber strength, length uniformity index, and maturity index.

Fig. 2
figure 2

Canonical variable analysis between fiber quality characteristics of Gossypium spp. accessions (Group 1) and G. barbadense L. var. brasiliensis accessions (Group 2) collected from native Amazonian communities in La Convención, Cusco, Perú. LEN: Staple length. MIC: Micronaire. STR: Fiber strength. ELO: Fiber elongation. SHO: Short fiber index. UNI: Length uniformity index. MAT: Maturity index

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Principal component analysis (PCA) was performed using quantitative data (Fig. 3), considering the two groups separated by species of native cotton accessions. The PCA of the quantitative data demonstrated that there was also similarity in the grouping of accession A3 with the Gossypium spp. accessions belonging to Group 1 (Fig. 3). Therefore, this A3 cotton accession is similar to the Group 1 accessions because of its positioning based on qualitative and quantitative data (Fig. 3). The first two principal components explained 77.6% of the variance in the data (Fig. 3). Among the fiber quality characteristics, the greatest contribution was related to the maturity index.

Fig. 3
figure 3

Principal component analysis of fiber quality characteristics for quantitative data for Gossypium spp. accessions (Group 1) and G. barbadense L. var. brasiliensis accessions (Group 2) collected from native Amazonian communities in La Convención, Cusco, Perú. LEN: Staple length. MIC: Micronaire. STR: Fiber strength. ELO: Fiber elongation. SHO: Short fiber index. UNI: Length uniformity index. MAT: Maturity index. In scree plot, 1, 2, 3 …18 represent the accessions A1, A2, A3… A18, respectively

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Discussion

The present study provided a detailed evaluation of the fiber characteristics of G. barbadense L. var. brasiliensis collected at several locations in the Peruvian Amazon region, using the HVI method to qualitatively (Table 3) and quantitatively (Table 4; Fig. 3) characterize key aspects of fiber quality. Staple length is a crucial indicator of fiber quality and varies among different cotton accessions (Table 3). Group 1 accessions represented by fiber samples of Gossypium spp. accessions collected from Koribeni and Poyentimari differ in their long fibers (> 28.6 mm). Similarly, the accession of G. barbadense L. var. brasiliensis collected from the native community of Shivankoreni also had long fibers (> 28.6 mm). Currently, the minimum fiber length required by the textile industry is 28.6 mm (Cotton Incorporated, 2018). The three long fiber length cotton accessions collected in this study have average stable length values between 29 and 31 mm. This observation highlights the importance of these collected native materials since longer fibers allow finer spinning and offer greater strength (Lewin 2006; Cassidy and Goswami, 2017; Orcón et al. 2019).

The fineness or thickness of the fibers was analyzed, highlighting the fiber samples collected from the native communities of Koribeni and Shivankoreni, which have a very coarse fineness. This finding is significant because it indicates the preservation of genes that maintain fiber thickness, a crucial attribute for specific applications in the textile industry. These genes could be fundamental for the development of future cotton varieties that combine durability with other desired properties, thus adapting to different market needs (Zellweger, 1999; IMAMT, 2014; Cotton Incorporated, 2018). However, it should be noted that a micronaire value of 6.90 may be too coarse for the manufacture of finer yarns, which constitutes a point of weakness for cotton accessions native to the Peruvian Amazon. For example, a micronaire of 6.90 and strength above 40 gf·tex−1 is very interesting for an 8 Ne yarn, but it may not be suitable for an 80 Ne yarn (IMAMT, 2014; Cotton Incorporated, 2018).

The fiber strength data showed that 83.3% of the samples analyzed had high strength, which is a critical factor for ensuring the durability of the fabrics. This quality is highly valued, as stronger fibers contribute significantly to the longevity and quality of the final product, making them preferable for a wide range of textile applications (Cotton Incorporated, 2018; Serquen-Lopez et al., 2019). The analyses carried out on fiber samples collected from Koribeni (Gossypium spp.) and Shivankoreni (G. barbadense L. var. brasiliensis) showed exceptionally high levels of strength, which highlights the value of the collected materials due to its genetic potential to improve strength in cultivars of commercially grown cotton. This discovery highlights the relevance of these samples in the research and development of cotton plants with improved durability characteristics, which is crucial for the textile industry.

Evaluation of fiber elongation, a crucial indicator of tissue quality and flexibility, revealed that both Gossypium spp. and Gossypium barbadense L. var. brasiliensis exhibited high elongation values. This high elasticity capacity is evidenced by fiber elongation values between 11% and 15%, with values above 7.7% being considered fibers with very high elongation capacity (Zellweger, 1999). Cotton samples from fibers with higher elongation (> 7.7%) can result in less breakage during fabric production and greater spinning efficiency (IMAMT, 2014). These findings emphasize the importance of both species in the production of high-quality fabrics, suggesting the significant potential for plant genetic improvement focused on elongation, a vital parameter for the textile industry according to previous research (Zellweger, 1999; IMAMT, 2014; Broetto et al., 2013).

The short fiber index was another key aspect evaluated in this study, highlighting the importance of a lower index for obtaining superior-quality textile products, as suggested by Salazar (2002) and López et al. (2018). The results showed diversity in the short-fiber indices among the samples, with Koribeni (Gossypium spp.). There are three accessions (A3, A15, and A18) collected from Shivankoreni, with length uniformity index ranged from intermediate (A3) to very low (A15). This characteristic underlines the potential of these varieties to produce high-quality yarns and fabrics, reinforcing the importance of conserving and selecting specific varieties of cotton with low short-fiber indices to improve the quality of the final product in the textile industry.

The evaluation of the uniformity of cotton fibers is essential for characterizing the quality and appearance of the fabric. This study revealed significant variability, from “very high” to “very low”. The samples collected from Koribeni (Gossypium spp.) were distinguished by “very high” uniformity. This variability underlines the need to carefully select cotton varieties to meet industrial standards, highlighting the importance of properties such as uniformity and fiber maturity in the final quality of textile products, as indicated by authoritative sources in the field (Zellweger, 1999; Salazar, 2002; IMAMT, 2014; Cotton Incorporated, 2018).

In the present study, Koribeni (Gossypium spp.) and Shivankoreni (Gossypium barbadense L. var. brasiliensis) cotton accessions were notable because of their alignment with superior quality standards. In contrast to the findings of former research, these findings illustrate the complex diversity of cotton quality, noting that appropriate selection varies depending on end-use and processing preferences. The importance of carrying out detailed analyses to fully understand these variants is emphasized. The interaction between current research, technological advances, and industrial experience is essential for improving the selection of quality cotton in future research and practical applications (Paz et al., 2019; Morales et al., 2023).

This study enriches the current literature by offering an exhaustive initial analysis of the qualities of G. barbadense L. var. brasiliensis from Amazonian communities in La Convención, Cusco. It is suggested that future studies adopt quantitative techniques and compare cotton with other cotton forms, thus improving our understanding of the properties and potential for different industrial uses of cotton.

Research on the fiber quality of G. barbadense L. var. brasiliensis in La Convención, Cusco, Perú provides new information on key characteristics for agronomy and textiles. Focusing on this specific cultivar, the study details its profile and relevance to the textile industry, highlighting its potential in textile selection and use. The results will enrich the knowledge base for future research and will also guide industry and farmers in strategic decisions about the conservation, cultivation, and processing of quality cotton from Amazonian regions.

Having access to reliable and recent data on cotton fiber quality allows farmers in the region’s growing areas to select proper cultivars. This choice must be made considering the demands and specifications of local and international fiber trade (Yang, 2019; MINAM, 2020). Furthermore, understanding which cotton species produce the best quality fibers allows farmers to improve their yield and profitability in commercial growing areas (Li et al., 2014; Cotton Incorporated, 2018).

Research with samples of G. barbadense L. var. brasiliensis collected in the native community of Shivankoreni in the Megantoni district reveals important findings that can improve knowledge and will allow the development of new technologies for better use of cotton adapted to Amazonian regions, benefiting local farmers by valuing the productivity and strength of their crops adapted to unfavorable conditions. This study highlights the value of native cotton for strengthening the relationship between artisanal producers and the textile industry, ensuring a supply of quality fiber. In addition, this study highlights the importance of helping rescue traditional Peruvian products, promoting access to specialized markets and improving the quality of life of farmers.

Conclusion

This study highlights the vital importance of protecting the genetic diversity of G. barbadense L. var. brasiliensis through the exceptional fiber quality, highlighting its valuable contribution to the textile industry. The results reveal the urgency of adopting conservation measures and plant genetic improvement strategies that explore the wide variability of these native cotton accessions, charting a promising path for future research and the adoption of sustainable agricultural practices. The identification of exceptional genotypes represents new possibilities for the development of cotton cultivars with superior quality characteristics, increasing sustainability and improving the competitiveness of the Peruvian Amazonian in textile industry worldwide. Our results also indicate the importance of preserving the genetic variability of cotton accessions native to the Peruvian Amazon in a Gene Bank, since this information can serve as a basis for new studies on the genetic improvement of the crop.