Preparation,composition, structure and properties of the <Emphasis Type="Italic">Kosteletzkya virginica</Emphasis> bast fiber

In this paper, the bast of the Kosteletzkya virginica are degummed and separated into fine fibers, the chemical composition, morphology, microstructure and mechanical properties of the Kosteletzkya virginica bast fibers are characterized by means of SEM, ART-FTIR, DSC-TGA, XRD and Instron tensile tester. The results show that the surface of the Kosteletzkya virginica bast fibers is smooth, and there are many visible grooves along the vertical section. Typical cellulose I in the Kosteletzkya virginica bast fibers is confirmed by FTIR and XRD analysis. The crystallinity of the Kosteletzkya virginica bast fibers is higher than that of the cotton fibers and lower than that of the castor-oil plant bast fibers. The beginning and maximum decomposition temperature of the Kosteletzkya virginica bast fibers are 252 and 347 °C respectively, which indicate that the Kosteletzkya virginica bast fibers have an appropriate thermal stability. The Kosteletzkya virginica bast fibers have a better mechanical properties and excellent hygroscopicity. All the results show that the Kosteletzkya virginica bast fiber is one of an ideal candidate for the new textile material.     

Effects of plant growth regulator treatments on stem vascular tissue development in linseed (Linum usitatissimum L.)

Linseed (Linum usitatissimum L.) is a widely grown source of industrial and edible oil. Other varieties of the same species (flax) are cultivated for the long, strong bast fibres of their stems. The bast fibres of linseed generally go unused, although there is growing interest in developing linseed into a dual-purpose flax from which both seed and fibre could be utilized. Towards this objective, an improved understanding is required of the role of plant growth regulators in stem and fibre development in linseed. We have tested the effects of applying varying combinations of gibberellic acid (GA₃), the auxin indole-3-acetic acid, and a GA biosynthesis inhibitor (paclobutrazol) to an elite linseed variety (CDC Bethune). Results showed that GA stimulated stem elongation, stem expansion and the proliferation, expansion, elongation and cell wall thickening of xylem fibres. The impact of GA on phloem tissues was less apparent, although GA had a positive effect on the number of bast fibres observed in stem transverse section, and GA₃ application in combination with IAA increased the thickness of bast fibre secondary walls nearly two-fold. Other than the bast fibre cell walls, IAA treatments (alone or in combination with GA₃) did not affect most aspects of linseed stem development, suggesting that the observed effects of GA were not mediated by cross-talk with IAA. The relationships defined here between GA, stem architecture, and bast fibre properties in linseed provide a useful framework for manipulation of fibre properties through breeding, biotechnology, and field treatments.     

Flax-cotton fiber blends: Miniature spinning,gin processing,and dust potential

Development of a flax (Linum usitatissimum L.) industry in North America is desired to supply a domestic source of clean, consistent quality textile fiber for blending with cotton. The objective of this work was to evaluate portions of traditional cotton gin equipment (extractor feeder and lint cleaner) and the “50-g cotton-spinning test (CST)” for flax. Dust was collected on an area sampler in an isolated card room to evaluate dust potential during textile pilot plant processing. Fibers retted by diverse means were cleaned on two separate portions of Continental Eagle's pilot plant cotton gin stand, the Super 96 Feeder and the 24D lint cleaner. Fibers separated and removed from flax stalks by these gin sections were compared against the standard ‘unified line’ processing technique of the USDA Flax Pilot Plant. Test yarns were then made in a CST with cotton and flax blends to provide an indirect measurement of fiber properties that can be related to the retting and gin cleaning processes. The yarns were tested for strength and evenness. Flax fibers that displayed the most favorable properties in the CST were then spun in 23 kg lots in the pilot plant at the following cotton/flax blend ratios: 100/0, 75/25, 50/50, 25/75, and 20/80. With modifications, it appears that portions of a cotton gin stand are able to process adequately small samples of properly retted flax stalks. The CST with minor adjustments provides useful data for ranking and further large-scale flax processing. As expected, it appears that flax fiber can be successfully cleaned on a cotton processing line and that increasing the amount of flax generates additional dust.     

Optimization for enzyme-retting of flax with pectate lyase

Flax (Linum usitatissimum L.) is an important commercial crop that supplies both linseed and bast fibers for multiple applications. Retting, which is a microbial process, separates industrially useful bast fibers from non-fiber stem tissues. While several methods (i.e., water- and dew-retting) are used to ret flax, more recently enzymes have been evaluated to replace methods used currently. Alkaline pectate lyase (PL) from the commercial product BioPrep 3000 and ethylenediaminetetraacetic acid (EDTA) from Mayoquest 200 as a calcium chelator were used in various formulations to ret flax stems. Retted stems were then mechanically cleaned through the USDA Flax Fiber Pilot Plant and passed through the Shirley Analyzer. The PL and chelator effectively retted flax from both fiber flax and linseed stems, and the use of enzyme plus chelator retted flax stems better than either component alone. Fiber yield and strength were greater than retting with a mixed-enzyme product that contained cellulases. Retting with PL and chelator was optimized based on fine-fiber yield, remaining shive content, and fiber properties. PL at levels of about 2% of the commercial product for 1 h at 55 °C followed by treatment with 18 mM EDTA for 23–24 h at 55 °C provided the best fibers based on these criteria. Yield and fiber properties determined by these tests were not improved with PL levels of 5% of the commercial product.     

Characterization and analysis of ligno-cellulosic seed fiber from Pergularia Daemia plant for textile applications

A hitherto uninvestigated ligno-cellulosic seed fiber from the plant Pergularia Daemia has been chosen for the current study to unravel its physical properties, and potentialities in textile applications. The raw, NaOH treated, and wax removed fibers were tested for their morphological and structural features by X-ray diffraction, SEM, FT-IR spectra, and thermal analysis by thermogravimetry and differential scanning calorimetry. The raw fibers have low cellulose content and less crystalline compared to cotton and are having hollow, smooth surface, and less density. The brittle nature and low elongation at break of virgin fiber makes it difficult for the spinning. It becomes spinnable after NaOH treatment due to the increased elongation at break by partial removal of lignin.     

Extraction of lipids from flax processing waste using hot ethanol

The cuticle of flax stems contains lipids that provide a protective barrier to pathogens and control moisture loss. These lipids include wax esters and long chain fatty alcohols or policosanols. Cuticle fragments generated during several different fiber processing operations retain these lipid compounds that represent a potential co-product. Samples of flax shives (i.e., lignified core tissues), processing dust, and cuticular fractions recovered from enzyme retting waste water were extracted on a laboratory scale with hot ethanol to remove the lipid compounds. Ethanol extracts were analyzed by gas chromatography to determine the amount and type of lipids recovered. The results demonstrated that hot ethanol effectively extracted the lipid compounds from cuticle fragments in all these samples. When the extract was cooled, the longer chain wax esters (i.e., chain length of 44 carbon atoms or larger) precipitated and could be separated from the shorter chain lipid components (i.e., fatty alcohols and aldehydes less than 44 carbons). Similar results were obtained using absolute ethanol or 95% ethanol (aqueous). This technique provides a very economical method to recover lipid fractions as potential value-added co-product from flax processing waste.     

Study of gene effects for cotton yield and Verticillium wilt tolerance in cotton plant (Gossypium hirsutum L.)

Verticillium wilt (VW), caused by Verticillium dahliae Kleb., is a destructive disease of cotton (Gossypium hirsutum L.). The use of resistant cultivars has long been considered the most practical and effective mean of control. The aim of this work was to study the quantitative genetic basis of Verticillium wilt resistance in Upland cotton by using five genotypes and their possible crosses without reciprocals selecting simultaneously for resistance and desirable agronomic characteristics. Five cotton cultivars and 10 F1s from half-diallel crosses were analyzed for VW resistance. The seed cotton yield, the number of bolls/ plant, and boll weight were measured and Verticillium wilt index (VWI) was estimated during two crop seasons in two different sites each year always on plots with naturally infested soil. Genetic components of variance were analyzed using the Hayman model. Analysis of variance for all characters showed significant differences between genotypes, without genotype-site interaction in most cases. Both, additive genetic variance component (D) and dominance genetic variance components (H1 and H2) were presented in all characters, except for VWI. D was the most important component for boll weight and VWI. Boll weight was the most correlated character with seed cotton yield and VWI. Broad sense heritability was high for boll weight and VWI, moderate for seed cotton yield and low for bolls per plant. Narrow sense heritability was moderate for boll weight, and high for VWI.     

Surface morphologies and internal fine structures of bast fibers

Fiber surface morphologies and associated internal structures are closely related to its properties. Unlike other fibers including cotton, bast fibers possess transverse nodes and fissures in cross-sectional and longitudinal directions. Their morphologies and associated internal structures were anatomically examined under the scanning electron microscope. The results showed that the morphologies of the nodes and the fissures of bast fibers varied depending on the construction of the inner fibril cellular layers. The transverse nodes and fissures were formed by the folding and spiralling of the cellular layers during plant growth. The dimensions of nodes and fissures were determined by the dislocations of the cellular layers. There were also many longitudinal fissures in bast fibers. Some deep longitudinal fissures even opened the fiber lumen for a short way along the fiber. In addition, the lumen channel of the bast fibers could be disturbed or disrupted by the nodes and the spirals of the internal cellular layers. The existence of the transverse nodes and fissures in the bast fibers could degrade the fiber mechanical properties, whereas the longitudinal fissures may contribute to the very rapid moisture absorption and desorption.     

中国农业科学院麻类研究所科学研究回顾与展望

本文较全面地回顾了中国农业科学院麻类研究所科研成就:苎麻、亚麻、黄/红麻新品种的选育与推广;麻类及同类纤维种质资源研究;麻类种植技术研究;麻类加工技术与加工机具的研究与推广;麻类生物脱胶与产品加工研究,特别是纤维质生产乙醇及环保型麻地膜的研究。本文还分析了未来该所麻业发展的走向:从麻类作物拓展到纤维植物;加工手段从农业微生物拓展到酶制剂;产品从传统的纺织原料拓展到生物能源与生物材料。     

加拿大麻类研究概况

由于气候、历史和主要作物的竞争等原因,加拿大目前种植的麻类作物仅限于亚麻和大麻,作者介绍了加拿大麻类作物育种、种植、利用、科研方面的概况,并指出随着消费者对环保的日益重视和麻产品日益增长的需求,加拿大的麻类研究迎来了一个转折时期,加拿大麻类产业将会得到更大的发展.     

Pulp and paper from kenaf bast fibers

Samples of kenaf (Hibiscus cannabinus) grown in Malaysia were examined to determine the kraft pulp and papermaking properties of their bast (or bark) fibers. Using kraft pulping process showed that bast fibers were relatively easy to cook resulting good pulp yields in the range of 45–51%. The bast pulp produced sheets with great density, tear index and dry zero-span breaking length. Kenaf bast fiber is considered promising for production of high-grade printing, writing and specialty papers.     

Physico-chemical characteristics of a seed fiber arised from <Emphasis Type="Italic">Pergularia Tomentosa</Emphasis> L.

In the present paper, we analyze a seed fiber arising from Pergularia tomentosa L. (PTL). It was, primarily, characterized using different techniques. The morphology of the fibers was observed via Scanning Electron Microscopy (SEM). They are also checked in term of decomposition behavior through TGA/DTG instrument. The cristallinity index was determined using XRD and it was about 52 %. The chemical composition in terms of moisture percent, ash, waxes and fats, lignin, hemicellulose and cellulose were, respectively 8.5 %, 2.74 %, 1.88 %, 8.6 %, 16 % and 43.8 %. The contact angle value was measured and the evolution of drop profile was captured with video-camera using GBX Tensiometer Surfaces Sciences Studies. Further, fibers were dyed with Methylene Blue, Direct Red 79, Sumifix supra yellow 3RF and Reactive Blue 198. Color coordinates (ΔL*, Δa*, Δb*, ΔC* and ΔH*) of the samples were so measured. All obtained data were compared to cotton fibers and some other cellulosic fibers. The Results revealed that, based on such properties, PTLF could be a competitive fiber in many applications field (textile weaving, composites, etc).     

Improving the use of kenaf for kraft pulping by using mixtures of bast and core fibers

Kenaf (Hibiscus cannabinus L.) is a herbaceous annual plant amenable to use as a papermaking raw material. Kraft and soda pulping of kenaf have so far been done exclusively on the bark fraction (about 34–38% of the stem) or whole stem of the plant. Using kenaf bark exploits the higher quality of its bast fibers but reduces the typically high crop yields of this plant. In any case, core kraft pulp has acceptable properties some of which (e.g. tensile index, burst index) can even surpass those of bark pulp. Pulp made from both fractions has been found to exhibit better bonding properties than bark pulp. However, too high a proportion of core fibers can result in difficult drainage, a low tear strength or poor air permeability. These problems restrict the proportion of core that can be mixed with bast fibers, hinders separation of the two fractions and raises operational costs.The primary purpose of this study was to examine the influence of the core–bark ratio on the properties of mixed kenaf pulp. We used unrefined core pulp and refined bark pulp. Based on the results for kraft sacks, obtaining kenaf paper from both fractions has some advantages. Because Gurley air porosity changed dramatically with the proportion of core pulp used, it was used to determine the maximum amount of core fibers to be added to bast fibers. A proportion of up to 34% was found to have no adverse effect on air permeability. Such a proportion allowed paper strength to be preserved with an acceptable tear index (19.8 mN m²/g) and excellent tensile index (72 N m/g). Also, energy consumption was reduced if only the bark fraction was refined. The proposed strategy thus provides increased fiber yields of kenaf per hectare per year and valorizes the core fraction.     

Close Association between Aleurone Traits and Lipid Contents of Rice Grains Observed in Widely Different GeneticResources of Oryza sativa

Abstract

We investigated 321 varieties to identify the aleurone traits that are closely related to the lipid content of rice. Brown rice seeds were cut crosswise near the center with a razor blade and the cut surface was stained with Oil Red O, and then observed under integrated fluorescence microscope (BZ9000). We found wide variations among varieties in the area stained, but the japonica group contained many varieties with a large stained area. We selected 17 representative varieties covering the whole range of stained areas and confirmed the thickness of aleurone layer using Kawamoto’s film method (micro-thin sections that were created with cryomicrotome). Aleurone traits were examined under a light microscope and measured. We found a strong correlation between the area of the aleurone layer and the stained area (r = 0.799***) and between the thickness of the aleurone layer and the thickness of the stained region (r = 0.543*). The area of the stained region therefore provides a fast and effective indicator for selecting varieties for the thickness of the aleurone layer. We also measured the amount (mg per 100 seeds) and proportion of triacylglycerols (TAGs) to 1 g of seed (mg g-¹) in brown rice seeds without embryos. The amount and proportion of TAG to 1 g of seed were both significantly correlated with the area, average thickness and percentage of aleurone layer. This suggests that the aleurone traits will be good indicators for the selection of varieties with high levels of TAG.     

Evaluation of the fineness of degummed bast fibers

Fiber fineness characteristics are important for yarn production and quality. In this paper, degummed bast fibers such as hemp, flax and ramie have been examined with the Optical Fiber Diameter Analyzer (OFDA100 and OFDA2000) systems for fiber fineness, in comparison with the conventional image analysis and the Wira airflow tester. The correlation between the results from these measurements was analysed. The results indicate that there is a significant linear co-relation between the fiber fineness measurement results obtained from those different systems. In addition, the mean fiber width and its coefficient of variation obtained from the OFDA100 system are smaller than those obtained from the OFDA2000 system, due to the difference in sample preparation methods. The OFDA2000 system can also measure the fiber fineness profile along the bast fiber plants, which can be useful for plant breeding.     

Accumulation of cadmium by flax and linseed cultivars in field-simulated conditions: A potential for phytoremediation of Cd-contaminated soils

The possibility of use of two technological types of Linum usitatissimum L., namely flax (grown for fibre) and linseed (grown for seed), for phytoextraction of cadmium (Cd) from Cd-contaminated soil was studied. A four-year field-simulated experiment was carried out with 6 flax and 4 linseed cultivars in order to study organ accumulation of Cd by flax and linseed plants at artificial concentration range 10-1000 mg Cd kg⁻¹ soil. The most Cd was accumulated by roots, followed by shoots, while reproductive parts (capsules and seeds) played comparably smaller role. The increasing soil Cd concentration resulted in increasing Cd accumulation by roots, while transport to above-ground plant parts was progresivelly inhibited. Even high soil Cd concentrations (1000 mg Cd kg⁻¹ soil) had not dramatic negative effect on plant growth and development. Cultivar differences as well as the differences between both technological Linum types have been found in Cd accumulation (flax being better Cd accumulator than linseed). Nevertheless, the recorded variation between technological types and within cultivars is in multiples of Cd values (units of mg Cd kg⁻¹ DW), not in orders of magnitude as needed for practical phytoextraction. A significant year-to-year effect on plant growth/development resulting in high variation in Cd accumulation was observed. Flax cv. Jitka exhibited good transport of Cd from roots to above-ground parts, while flax cv. Merkur showed high retention of Cd in roots. Further, the contrasting cultivars in total Cd accumulation (high accumulating flax cv. Jitka versus low accumulating linseed cv. Jupiter) were selected for future experiments. The uptake of Cd by flax/ linseed from ha per season was calculated and the strategy for flax/linseed growing on heavy metal polluted soils with subsequent utilization of heavy metal-contaminated biomass is discussed.     

Natural seed coats provide protection against penetration by Callosobruchus maculatus (Coleoptera: Bruchidae) larvae

The seed coat is the first host or non-host tissue contacted by bruchids, suggesting its participation in the evolutionary adaptation of bruchids to favor legume seeds. In the present work, we studied the influence of seed coat on the ability of Callosobruchus maculatus (Coleoptera: Bruchidae F.) larvae to penetrate, develop in and survive on seeds. Our results showed that the oviposition, larval eclosion and adult emergence of C. maculatus were drastically reduced in some seeds and that the time necessary for the surviving larvae to perforate the seed coat increased by up to 100% in these seeds. The surviving larvae that crossed the Phaseolus vulgaris (Leguminosae B.) seed coat reached only 55.6% of the mass of a normal larva. The seed coat of some seeds was very toxic to insect larval development. Despite individual variations, seed coats were generally highly restrictive to the development and survival of the bruchid. The study of the seed coat efficiency as a protection tissue against penetration of insects can provide an important tool for new strategies for crop protection. The strengthening of the seed coat defense mechanisms may represent an efficient strategy because the seed chemical defense barrier would be moved to the outer structures and damage to the embryo would be minimized or avoided.     

Electroneutral cornstarch by quaternization and sulfosuccinylation to improve the adhesion of cold starch paste to raw cotton for low-temperature sizing

The objective of this research was to survey the effects of starch quaternization and sulfosuccinylation on the adhesion of cold starch paste to raw cotton fibers for cotton warp sizing at low temperature. Acid-thinned cornstarch (ATS) was quaternized and then sulfosuccinylated to introduce 3-(trimethylammonium chloride)-2-hydroxypropyl and sulfosuccinate substituents onto its backbones. The electroneutrality of starch samples prepared was achieved by maintaining a constant mole ratio (5.3:1) of the two substituents. A series of electroneutral cornstarch (ECS) samples with different levels of the substituents were derived by altering the feed ratio of the modifying reagents to starch for determining desirable level of starch modification. Adverse influences of cotton wax and starch retrogradation on the adhesion of cold starch paste to raw cotton fibers were evaluated to illustrate the effectiveness of starch quaternization and sulfosuccinylation. It was found that the modification was able to alleviate the adverse influence of starch retrogradation and ameliorate the adhesion to the fibers at low temperature. Higher level of the modification led to less retrogradation and resulted in strong adhesion. Furthermore, the adverse influence of cotton wax on the adhesion could be eliminated after a pre-wetting treatment of raw cotton warps with hot water. The adhesion of ECS paste to raw cotton at 60 °C was statically the same as that of ATS at 95 °C when total DS of ECS was 0.0443 or higher.     

Pilot plant for processing flax fiber

A flax fiber pilot plant is needed to process small samples of flax straw into fibers to facilitate research on retting and fiber properties. Our objective was to develop and test a modular design for a flax processing pilot plant based on a commercial line that was capable of cleaning fiber and seed flax straw from unretted, dew-retted, and enzyme-retted samples. The USDA Flax Fiber Pilot Plant (Flax-PP), which is the only research facility of this type in the United States, was designed according to the commercial ‘Unified Line’ (Czech Flax Machinery), but smaller and constructed in four individual modules. The modules and their order for processing were as follows: 9-roller calender, top shaker, scutching wheel, top shaker, 5-roller calender, and top shaker. Illustrations and diagrams of the operating modules are presented. Unretted ‘Neche’ linseed flax, dew-retted ‘Natasja’, and enzyme-retted ‘Jordan’ fiber flax were processed, and the cumulative weight loss of material at successive processing steps was determined to assess the effectiveness of cleaning. Fiber strength, fineness, and elongation were determined for the retted samples after cleaning through all the steps in the Flax-PP. A yield of fine fiber from the retted stems processed through the Flax-PP was acquired from further cleaning and refining by passage through a Shirley Analyzer. The various samples behaved differently at different stages of processing and the resulting fibers had different properties. The dew-retted Natasja fibers were stronger and finer than the enzyme-retted Jordan flax after pilot plant processing, but the Jordan fibers appeared cleaner and better retted. The Flax-PP effectively processed samples of diverse characteristics and will facilitate integrated research on retting methods for fibers with tailored properties.     

Wild safflower species (Carthamus oxyacanthus): A possible source of resistance to the safflower fly (Acanthiophilus helianthi)

Safflower (Carthamus tinctorius L.) is an important oil seed crop with growing importance in many countries around the world. However, safflower fly (Acanthiophilus helianthi Rossi) is one of the main limiting factors to expand the production area of the crop in several countries. Since host plant-resistance is the most efficient method for pest management, we evaluated a germplasm of wild accessions (Carthamus oxyacanthus Bieb.) with mostly brown–black seed coat color along with some white-seeded cultivated safflower genotypes for resistance to safflower fly. The results showed that there was a significant difference between two species for safflower fly damage with all cultivated genotypes being susceptible. However, for the accessions of C. oxyacanthus, a wide range of resistance was observed. In a choice experiment and natural infestation, 35.3–78.9 percent of heads per plant were infested in genotypes of C. tinctorius while for the accessions of C. oxyacanthus this was much smaller and ranged from 1.6 to 13.6%. In addition, percentage of seed yield loss per infested plant was more drastic in cultivated safflower (29.0–72.8%) than the wild accessions (0.0–21.4%). In the no-choice experiment, fly population was dramatically decreased in the wild accessions due to larval mortality and possibility of antibiosis. There was a strong relationship between brown–black seed coat color and resistance to safflower fly indicating the possibility of using this trait in breeding programs of safflower to develop fly-resistant cultivars.