Bast Fibre Yield Research Articles

Cloning and functional mechanism of the dwarf gene gba affecting stem elongation and cellulose biosynthesis in jute (Corchorus olitorius).

Plant height (PH) is an important factor affecting bast fiber yield in jute. Here, we report the mechanism of dwarfism in the 'Guangbaai' (gba) of jute. The mutant gba had shorter internode length and cell length compared to the standard cultivar 'TaiZi 4' (TZ4). Exogenous GA3 treatment indicated that gba is a GA-insensitive dwarf mutant. Quantitative trait locus (QTL) analysis of three PH-related traits via a high-density genetic linkage map according to re-seq showed that a total of 25 QTLs were identified, including 13 QTLs for PH, with phenotypic variation explained ranging from 2.42 to 74.16%. Notably, the functional mechanism of the candidate gene CoGID1a, the gibberellic acid receptor, of the major locus qPHIL5 was evaluated by transgenic analysis and virus-induced gene silencing. A dwarf phenotype-related single nucleotide mutation in CoGID1a was identified in gba, which was also unique to the dwarf phenotype of gba among 57 cultivars. Cogid1a was unable to interact with the growth-repressor DELLA even in the presence of highly accumulated gibberellins in gba. Differentially expressed genes between transcriptomes of gba and TZ4 after GA3 treatment indicated up-regulation of genes involved in gibberellin and cellulose synthesis in gba. Interestingly, it was found that up-regulation of CoMYB46, a key transcription factor in the secondary cell wall, by the highly accumulated gibberellins in gba promoted the expression of cellulose synthase genes CoCesA4 and CoCesA7. These findings provide valuable insights into fiber development affected by endogenous gibberellin accumulation in plants.

Management of speargrass [<i>Imperata cylindrica (L.) Raeuschel</i>] in of southern agro-ecologies of Nigeria

Speargrass [Imperata cylindrica (L.) Raeuschel] infestation limits crop growth and yield. The effects of tillage methods, kenaf genotypes, and plant spacing patterns were studied for speargrass suppression at Eruwa (Derived Savanna) and Kishi (Southern Guinea Savanna) in 2015 and 2016. These were randomized in a Split-split plot design with three replicates. Agronomic data collected were analyzed, and the means were separated at P ≤ 0.05. Results showed that tillage enhanced weed control efficiency (10%), improved I. cylindrica suppression, and kenaf performance, relative to plant sown in no-till plots at both locations. The bast-fibre yield was higher in Ifeken DI 400 than in Ifeken 400 at Eruwa, but genotypes had similar bast-fibre yield at Kishi. Also, both genotypes had comparable I. cylindrica biomass and weed control efficiency at Kishi, while Ifeken 400 had higher weed control efficiency than Ifeken DI 400 at Eruwa, due to better suppression of I. cylindrica. The agronomic traits measured and weed control efficiency (WCE %) had a substantial inverse relationship with I. cylindrical growth at both locations. Tillage improved bast fibre yield (26 – 32%), core fibre yield (20 – 28%), and seed yield (26 – 59 %) relative to no-tilled plots. Ifeken 400 showed superior weed-suppressive traits and optimum fibre yield to Ifeken DI 400 at both locations. Tilling speargrass-infested land, with kenaf plant spacing of 50 cm × 10 cm and 50 cm × 15 cm with early canopy formation and better weed suppression are considered for an integratedspeargrass management scheme.

Comparative transcriptomics discovers the genetic basis of contrasting waterlogging tolerance between two cultivated jute species

Farmers prefer dark jute (Corchorus olitorius var. O-9897) to white jute (Corchorus capsularis var. CVL-1) because dark jute produces more bast fiber and has greater fiber strength. Crossing incompatibility between these two jute species is the main genetic barrier to transfer waterlogging-tolerant capability from white jute to dark jute. So, to develop a waterlogging-tolerant dark jute variety, gene(s) of interest for certain morphological, anatomical, and physiological features must be transferred from white jute to dark jute without the use of traditional crossing techniques. Therefore, we investigated the comparative gene expressions of CVL-1 and O-9897 tap roots using RNA-Seq and qRT-PCR techniques as well as observed the morphological, histological and physiological behavior under waterlogging treatments. CVL-1 develops schizogenous aerenchyma for oxygen storage, as well as vascular tissues in its adventitious roots for moving water and nutrients from the water solution to the stem, which keeps its tap root less active and so saves more energy in its tap roots. O-9897, on the other hand, degrades its adventitious roots with lysigenous aerenchyma, which results in the formation of no vascular tissues. Thus, O-9897 solely uses its adventitious roots for oxygen storage, while its tap roots are used for water and nutrient transfer, resulting in constant energy depletion in O-9897 tap roots. Consequently, CVL-1 can maintain its normal growth and O-9897 diminishes its bast fiber yield with the lack of energy. The key genes involved in the biogenesis of energy and phytohormones have been more inducing in CVL-1 than O-9897. ATP-producing glycolytic enzyme, phosphoglycerate kinase (CCACVL1_10615) showed remarkable upregulation in CVL-1 while missing in O-9897, playing a vital role in CVL-1 waterlogging tolerance. Our findings reveal a novel mechanism of waterlogging tolerance in white jute, which can be applied to the development of waterlogging-tolerant dark jute varieties in the future.

Multi-environment assessment of a yellow hemp (Cannabis sativa L.) cultivar’s eco-physiology and productivity under varying levels of nitrogen fertilisation

Yellow stalked cultivars of hemp (Cannabis sativa L.) were reported to have a superior fibre processability than green cultivars, but the effects of the yellow trait on productivity and ecophysiology of hemp remain unexplored. It is hypothesised that yellow stalked cultivars are characterised by a low Nitrogen Uptake Efficiency. Three field scale experiments involving a yellow cultivar ('Fibror 79') and a green one ('Futura 75') grown under varying levels of nitrogen fertilisation were conducted in Northern Italy and in Wales, to investigate the effects of the yellow trait on hemp productivity and eco-physiology. The results showed that 'Fibror 79' displays a slightly lower biomass productivity than 'Futura 75' under nitrogen-limiting conditions, owing to lower Leaf Area Index and light interception capacity during the early growth phase, and potentially due to a lower radiation use efficiency. However, the productivity was not significantly different between cultivars under non-limiting nitrogen conditions. The Nitrogen Uptake Efficiency did not differ between the two cultivars, which failed to support the hypothesis of this work. Instead, Nitrogen Use Efficiency and Nitrogen Utilisation Efficiency were significantly higher for 'Futura 75' than for 'Fibror 79' under nitrogen-limiting conditions. 'Futura 75' appeared better suited than 'Fibror 79' for dual- and multi-purpose production in Italy, while the reverse was true in Wales. 'Fibror 79' better suits a strategy of single-use fibre production owing to its higher bast fibre content and fibre yield.

Mediation and ANCOVA Models to Study the Influence of Solvent Retting Traits and Plant Physique on Bast Fiber Yield and Retting Time

ABSTRACT The study aims in applying two statistical tools to analyze the retting behavior of plant stems for extracting bast fibers for industrial applications. At first, a mediation model is employed to investigate the first hypothesis of this work that involves studying the color response of the retted solvent as a function of retting time on the responsible variable, fiber yield (%). Statistically, there is a significant indirect effect of retting time on fiber yield (%) through retting trait (β = −0.0142, 95% C.I. [−0.0274, −0.0011]) – a statistical inference bolstered by the Sobel test result, confirming the mediation effect (p-value = 0.0329 < 0.05; z-score = −2.1334; bootstrapping of 5000 resamples). Next, the second hypothesis of the current work involves analyzing the impact of stem form-factors on their retting time using the statistical tool, ANCOVA. The partial- η2 indicates that cultivar treatment accounts for 30% variance of the retting time while controlling for the effects of two covariates – diameter and length of the stems, in this case. By controlling the Type-I error, Bonferroni and similar post-hoc tests also confirm the statistical significance of cultivar categories pertaining to their mean retting time. Future work could focus on these underlying hypotheses and study the impact of microorganisms, environmental factors, and cultivar treatment variables on the retting time to optimize the overall fiber yield and production process.

Analysis of inter-nodal properties of two industrial hemp cultivars (Fasamo and Ferimon 12) and their relationships with plant density and row spacing

Research and development of an efficient production system for industrial hemp (Cannabis sativa L.) fiber needs to integrate multidisciplinary knowledge from cultivation to processing of plant materials. This study investigated two industrial hemp cultivars (Fasamo and Ferimon 12) for their inter-nodal properties, i.e., length and diameter. The relationship of the inter-nodal properties with agronomic factors such as planting density (40, 80, 120, 160 plants/m2) and row spacing (15 and 30 cm) was examined in a field experiment. The findings suggested that plants cultivated at higher plant densities (e.g., 80 and 160 plants/m2) had a smaller inter-nodal diameter and longer inter-nodal length. Row spacing did not show a significant effect on the Fasamo cultivar. However, row spacing had a significant effect on the Ferimon 12 cultivar that might imply more intense intra-specific competition of the taller plants for sunlight. The inter-nodal length pattern resembling a bimodal distribution might indicate crop maturity. However, further research into the inter-nodal length pattern is recommended. When the inter-nodal properties and other crop parameters (e.g., bast fiber yield) were interpreted together, they could convey important information, including the extent of crop maturity and a suitable harvesting period for more bast or hurd fiber production. Although the study generated interesting and promising results from the inter-nodal property analysis, further research into the internodal properties in relation to other influential agronomic factors is recommended.

Morpho-phenetical study of high yielding tossa jute variety BJRI Tossa Pat 7 (MG-1) for bast fibre yield and qualities

Background and aim of the studyTossa jute (Corchorus olitorius) is a natural fibre crop produces good quality fiber having great demand for industrial uses. High yielding tossa jute variety is very important in Bangladesh. Materials and methodsBangladesh Jute Research Institute (BJRI) has developed a new tossa jute variety (BJRI Tossa Pat 7) through pure line selection (PLS) from another pre-released variety named OM-1 during 2017. The new variety was evaluated for fiber yield and attributing phonological traits through comparing with another pre-released variety named BJRI Tossa Pat 5 (O-795) in RCB design at six locations during 2015–2018. ResultsDistinct morphological traits i.e. ovate lanceolate glossy leaves; full green plant were found in MG-1 and stem & stipule red; ovate lanceolate leaves in O-795. MG-1 showed higher fiber yield (3.39–3.40 t ha−1) where, O-795 showed 3.10–3.22 t ha−1 as means of their maximum performances for three years at both farmers' plots and research fields. MG-1 gave higher plant height, base diameter, fiber yield than O-795 at both research stations and farmers’ fields. Even after sowing at 10–15 March, MG-1 gave late flowering; lower leaf size, leaf angle, green leaf biomass and node number; maximum inter-nodal length, bark diameter, bark thickness and fiber bundle cells; and finally golden bright quality fiber than O-795. If both varieties were sown at 2nd to 3rd week of March, and harvested at 110 days old, MG-1 gave 5–7% higher fiber yield than O-795. ConclusionUndoubtedly, MG-1 is a good tossa jute variety for its fiber yield and quality than pre-released varieties. RecommendationMG-1 having good fiber yield would be used for commercial cultivation by the farmers to contribute to the national economy.

Assessment of plant population on growth, fibre and seed yield of kenaf (Hibiscus cannabinus L.) in Ibadan western Nigeria

Kenaf is a multi-purpose crop with numerous industrial uses. Its production is constrained by poor cultural and agronomic practices which reduce yield. Inappropriate spacing among others could result in low yield. Effect of plant spacing on growth and yield of kenaf was investigated in Ibadan, Nigeria. Kenaf seed was sown (2 plants/stand) at three plant spacing: 50×15, 50×20, 50×25 cm was assessed for seed and bast fibre yields using randomized complete block design (RCBD) with three replicates. The analysis was done using statistical analysis system (SAS). Plant spacing differed significantly for bast fibre and seed yields. Highest bast fibre yield (0.9±0.03) and seed yield (0.5±0.01) were obtained at 50×20 cm and 50×25 cm spacing, respectively, while the lowest bast fibre yield (0.7±0.01) and seed yield (0.3±0.01) were obtained at 50×15 cm spacing. Spacing of 50 × 15 cm and 50 × 20 cm are appropriate when planting for fibre while 50 × 25cm is appropriate for seed production.&#x0D; Keywords: Kenaf, Spacing, Fibre and Seed yield.

Genes with bast fiber-specific expression in flax plants - Molecular keys for targeted fiber crop improvement

Plant fibers, owing to their unique properties, have been used by mankind for the production of textiles and composite materials for thousands of years. Currently, the use of plant fibers in various innovative fields has become very popular as they are an environmentally friendly, biodegradable, and renewable resource. Each of the numerous fiber-consuming industrial fields has special demands on the properties of fiber. The quality of plant fibers is a multicomponent parameter that depends on morphological and anatomical characteristics, as well as on the structure and proportions of fiber bundle chemical constituents. These features are formed during plant ontogenesis and can be subjected to management by manipulating the key stages of fiber development: fiber elongation by intrusive growth and cell wall thickening. To determine the molecular keys for manipulating certain fiber features related to crop quality, we summarized the RNA-Seq data obtained for different flax tissues and revealed the genes specifically upregulated in bast fibers. These genes were additionally subdivided into three groups considering the differential expression of the genes at the stage of fiber intrusive elongation versus the stage of cell wall thickening. The first group included genes specifically expressed in fibers without differential expression at the two stages. The second included those upregulated at the intrusive elongation stage compared to the further stage of development, and the third included those upregulated at tertiary cell wall deposition. The qPCR analysis of the expression level of the selected genes in fibers isolated from the developing plants of several varieties of fiber and linseed, Linum usitatissimum, as well as of two wild flax species revealed that the samples cluster into different groups in accordance with bast fiber yield and quality. The genes with tissue- and stage-specific characters of expression provide new insights into the mechanisms of fiber development and may serve as a target for molecular-genetic modulation of crop quality, as there is a high possibility of exclusively affecting bast fiber parameters, without influencing other tissues.

Copper Uptake and Accumulation, Ultra-Structural Alteration, and Bast Fibre Yield and Quality of Fibrous Jute (Corchorus capsularis L.) Plants Grown Under Two Different Soils of China.

Copper (Cu) is an essential heavy metal for plants, but high Cu concentration in the soil causes phytotoxicity. Some plants, however, possess a system that can overcome Cu toxicity, such as Cu localization, and an active antioxidant defence system to reduce oxidative damage induced by high Cu concentration. The present study was conducted to explore the phytoremediation potential, morpho-physiological traits, antioxidant capacity, and fibre quality of jute (Corchorus capsularis) grown in a mixture of Cu-contaminated soil and natural soil at ratios of 0:1 (control), 1:0, 1:1, 1:2 and 1:4. Our results showed that high Cu concentration in the soil decreased plant growth, plant biomass, chlorophyll content, gaseous exchange, and fibre yield while increasing reactive oxygen species (ROS), which indicated oxidative stress induced by high Cu concentration in the soil. Antioxidant enzymes, such as superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) scavenge ROS in plant cells/tissues. Furthermore, high Cu concentration did not significantly worsen the fibre quality of C. capsularis, and this plant was able to accumulate a large amount of Cu, with higher Cu accumulation in its shoots than in its roots. Transmission electron microscopy (TEM) revealed that Cu toxicity affected different organelles of C. capsularis, with the chloroplast as the most affected organelle. On the basis of these results, we concluded that high Cu concentration was toxic to C. capsularis, reducing crop yield and plant productivity, but showing little effect on plant fibre yield. Hence, C. capsularis, as a fibrous crop, can accumulate a high concentration of Cu when grown in Cu-contaminated sites.

Effect of varying rates of organic fertilizer on the growth and fibre yield of Kenaf (Hibiscus cannabinus L.)

Hibiscus cannabinus L. or kenaf is a fast growing and multipurpose annual crop planted for its horticultural and economic importance. Little is known about its response to different rates of organic fertilizer in Nigeria. The objective of the study was therefore to evaluate the effects of different rates of commercially produced organic fertilizer (Aleshinloye organic fertilizer to be precise) on crop growth rate, vegetative growth and biomass accumulation in kenaf Five different rates of organic fertilizer equivalent to: 0, 70, 100, 130 and 160 kg N ha-1 replicated three times were used in a randomized complete block design (RCBD). There were contrasting results on the effects of fertilizer rates on growth and physiology of kenaf. Significant effects were observed for some agronomic parameters such as plant height, stem diameter and fibre yield. The application of organic fertilizer at varying rates increased the bast fibre yield of the Ifeken 400 variety of kenaf from 67.29 g/m2 (control) to 98.70, 147.88 and 157.40 g/m2, in those grown on soil amended with 70, 100 and 130 kg N ha-1 of organic fertilizer respectively. Organic fertilizer could be utilized for the cultivation of kenaf in Nigeria but the rate to apply depends on the nutrient content of the organic fertilizer.Keywords: Kenaf, Growth, Organic fertilizer, rates and fibre yield

Key Stages of Fiber Development as Determinants of Bast Fiber Yield and Quality

Plant fibers find wide application in various fields that demand specific parameters of fiber quality. To develop approaches for the improvement of yield and quality of bast fibers, the knowledge of the fiber developmental stages and of the key molecular players that are responsible for a certain parameter, are vitally important. In the present review the key stages of fiber development, such as initiation, intrusive growth, and formation of thickened cell wall layers (secondary and tertiary cell walls) are considered, as well as the impact of each of these stages on the final parameters of fiber yield and quality. The problems and perspectives of crop quality regulation are discussed.

Draft genome analysis provides insights into the fiber yield, crude protein biosynthesis, and vegetative growth of domesticated ramie (Boehmeria nivea L. Gaud).

Plentiful bast fiber, a high crude protein content, and vigorous vegetative growth make ramie a popular fiber and forage crop. Here, we report the draft genome of ramie, along with a genomic comparison and evolutionary analysis. The draft genome contained a sequence of approximately 335.6 Mb with 42,463 predicted genes. A high-density genetic map with 4,338 single nucleotide polymorphisms (SNPs) was developed and used to anchor the genome sequence, thus, creating an integrated genetic and physical map containing a 58.2-Mb genome sequence and 4,304 molecular markers. A genomic comparison identified 1,075 unique gene families in ramie, containing 4,082 genes. Among these unique genes, five were cellulose synthase genes that were specifically expressed in stem bark, and 3 encoded a WAT1-related protein, suggesting that they are probably related to high bast fiber yield. An evolutionary analysis detected 106 positively selected genes, 22 of which were related to nitrogen metabolism, indicating that they are probably responsible for the crude protein content and vegetative growth of domesticated varieties. This study is the first to characterize the genome and develop a high-density genetic map of ramie and provides a basis for the genetic and molecular study of this crop.

Yellow Vein Mosaic disease in kenaf (&lt;i&gt;Hibiscus cannabinus&lt;/i&gt; l.) under different sowing dates in two agroecologies

Determination of appropriate sowing dates is an important approach towards obtaining optimum crop yield as it affects the resistance/susceptibility of crops to insect pests and diseases. The study investigated the effect of three sowing dates (May, June and July) on the occurrence and incidence of yellow vein mosaic disease in kenaf variety (IFEKEN-100) planted in the experimental fields of the Institute of Agricultural Research and Training (IAR&T) located in Ibadan and Ilora. The incidence of yellow vein mosaic disease was high in May at the two locations with means of 25 and 30% for Ibadan and Ilora, respectively. Plant height was not significantly different in the two locations across the three months. The highest stem diameter was obtained in May from Ilora and Ibadan with means of 1.44 and 1.53 cm, respectively. The best bast fiber yield was recorded in June at Ibadan with a mean value of 1.72 tha-1. Nucleic acid spot hybridization (NASH) was used to confirm the disease and the results revealed that Begomovirus was present in kenaf sowm in the two locations during the period of the three months except in kenaf sown in July at Ilora. The results of this study revealed the importance of sowing dates on the occurrence of viral diseases on the field. If the sowing date is optimum, the effect of viruses may not be pronounced in the crop as seen in the month of June having relatively low virus incidence as well as the highest plant height and bast fibre yield. Keywords : Begomovirus, kenaf, nucleic acid hybridization, yield

Changes in hemp secondary fiber production related to technical fiber variability revealed by light microscopy and attenuated total reflectance Fourier transform infrared spectroscopy.

Interest in hemp (Cannabis sativa L.) is increasing due to the development of a new range of industrial applications based on bast fibers. However the variability of bast fiber yield and quality represents an important barrier to further exploitation. Primary and secondary fiber content was examined in two commercial hemp varieties (Fedora 17, Santhica 27) grown under contrasted sowing density and irrigation conditions. Both growing conditions and hemp varieties impact stem tissue architecture with a large effect on the proportion of secondary fibers but not primary fibers. Attenuated total reflectance infrared spectroscopy allowed the discrimination of manually-isolated native primary fibers and secondary fibers but did not reveal any clustering according to growing conditions and variety. Infrared data were confirmed by wet chemistry analyses that revealed slight but significant differences between primary and secondary fiber cell wall composition. Infrared spectroscopy of technical fibers obtained after mechanical defibering revealed differences with native primary, but not secondary fibers and also discriminated samples obtained from plants grown under different conditions. Altogether the results suggested that the observed variability of hemp technical fibers could be partially explained by i) differences in secondary fiber production and ii) differential behavior during mechanical defibering resulting in unequal separation of primary and secondary fibers.

Comparing hemp (Cannabis sativa L.) cultivars for dual-purpose production under contrasting environments

Interest in hemp as a multi-purpose crop is growing worldwide and for the first time in 2015 it was cultivated in Europe on more than 20.000ha as a dual-purpose crop, for the seeds and for the fibre. In the present study, fibre and seed productivity of 14 commercial cultivars were tested in four contrasting European environments (Latvia, the Czech Republic, France, Italy). At full flowering, the stem yield ranged from 3.7Mgha−1 to 22.7Mgha−1, the bast fibre content ranged from 21% to 43%, and the bast fibre yield ranged from 1.3Mgha−1 to 7.4Mgha−1. When harvesting was postponed from full flowering until seed maturity, the stem yield of monoecious cultivars significantly increased but in dioecious cultivars it decreased at all tested sites, except for Italy. Only the early cultivars Fedora 17 and Markant produced seed in the most northern location Latvia. The seed yield ranged from 0.3Mgha−1 to 2.4Mgha−1 in Italy, France and the Czech Republic. The cultivar effect on stem and seed yield was mainly determined by the genetic variation in time of flowering. Stem yield at full flowering was strictly related to the duration of the vegetative phase while seed yield was lowest in the late flowering cultivar. The late cultivar CS is suitable for stem and fibre production as it had the highest stem yield at full flowering in all locations. Both Fedora 17 and Futura 75 are candidate cultivars for dual-purpose production in Italy, France and the Czech Republic, with Fedora 17 being more suitable for seed production and Futura 75 for fibre production.The application of modelling to design production strategies for dual-purpose hemp is promising. However, accurate parameterisation is needed based on large data sets and diverse genetic background.

A restriction-site-associated DNA (RAD) linkage map, comparative genomics and identification of QTL for histological fibre content coincident with those for retted bast fibre yield and its major components in jute (Corchorus olitorius L., Malvaceae s. l.)

We used RAD (restriction-site-associated DNA) sequencing to detect genome-wide SNPs and construct a dense linkage map using an intercross F2 population in jute (Corchorus olitorius). The linkage map comprising a total of 503 RAD markers in seven linkage groups spanned 358.5 cM with an average marker interval of 0.72 cM and covered 87.0 % of the genome. Genome-wide segregation distortion of the mapped loci (34.4 %) was non-random across the linkage map, with a directional bias mostly towards the female genotypes. Jute had maximum syntenic relationships with cocoa (47.5 % homology) and diploid cotton (29.2 % homology). However, synteny and collinearity were not conserved. Histological fibre content (FC; total number of fibre cell bundles in a stem cross section) was positively correlated with fibre yield (FY), plant height (PH), root weight (RW) and stem-base diameter (SBD). Broad-sense heritability estimates were high for all traits, with FC and FY showing maximum heritability (~93 %). QTL mapping based on the F2:3 phenotypes detected nine QTL across the two environments. The QTL for FC was coincident with one QTL each for FY, PH, RW and SBD on top of a single-SNP (C/T) marker at 40.2 cM on LG1, each accounting for ~7–11 % of the phenotypic variance. Two QTL linked in repulsion one each for PH and SBD, with varying degrees of overdominance, were associated with two single-SNP (C/T) markers on LG2, each accounting for ~17–18 % of the phenotypic variance. Few candidate genes were identified within the QTL regions. Our results would enable development of tools for marker-assisted selection in jute.

Ramie [Boehmeria nivea (L.) Gaud.] as a potential new fibre crop for the Mediterranean region: Growth, crop yield and fibre quality in a long-term field experiment in Central Italy

Ramie [Boehmeria nivea (L.) Gaud.] is a perennial herbaceous plant, of the Urticaceae family, native to China, Japan and Malay Peninsula, where it has been used as a textile fibre for many centuries. This species was introduced successfully in the Mediterranean region at the beginning of 1900, even though few researches have been carried out to assess the long-term productivity and stand duration in this area. For this reason, a 13-year field experiment was conducted, under the temperate climatic conditions of Central Italy, to evaluate the effects on ramie growth and yield of two different plant densities (50,000 and 33,300plantsha−1), two harvest times (June and October) and crop stand duration. The chemical composition (cellulose, hemicellulose and lignin content) of bast and core was evaluated too. Ramie showed a good adaptability to the pedo-climatic conditions of the study site, with a growing period that goes from the beginning of March to the beginning of October. The obtained results showed that the harvest time significantly affected all the analysed parameters, while the plant density had no significant effect on stem development and stem basal diameter, and on crop and bast fibre yield. Furthermore, no significant interaction was observed between the plant density and the harvest time on total plant or stem and bast fibre dry yield, and on the main biometric characteristics. In spite of its tropical origin, ramie appears to be suited to temperate conditions giving 8.70Mg/ha/year of stem dry yield and 2.46Mg/ha/year of dry bast fibre from the 2nd to the 13th year of growth. The dry ramie plant was composed by weight of 62% stems and 38% leaves and cymes. The results pointed out that the crop can persists for many years (up to 13) giving a stable off-take of stems and bast fibre.

A complete genetic linkage map and QTL analyses for bast fibre quality traits, yield and yield components in jute (Corchorus olitorius L.)

We report the first complete microsatellite genetic map of jute (Corchorus olitorius L.; 2n = 2x = 14) using an F6 recombinant inbred population. Of the 403 microsatellite markers screened, 82 were mapped on the seven linkage groups (LGs) that covered a total genetic distance of 799.9 cM, with an average marker interval of 10.7 cM. LG5 had the longest and LG7 the shortest genetic lengths, whereas LG1 had the maximum and LG7 the minimum number of markers. Segregation distortion of microsatellite loci was high (61%), with the majority of them (76%) skewed towards the female parent. Genomewide non-parametric single-marker analysis in combination with multiple quantitative trait loci (QTL)-models (MQM) mapping detected 26 definitive QTLs for bast fibre quality, yield and yield-related traits. These were unevenly distributed on six LGs, as colocalized clusters, at genomic sectors marked by 15 microsatellite loci. LG1 was the QTL-richest map sector, with the densest colocalized clusters of QTLs governing fibre yield, yield-related traits and tensile strength. Expectedly, favorable QTLs were derived from the desirable parents, except for nearly all of those of fibre fineness, which might be due to the creation of new gene combinations. Our results will be a good starting point for further genome analyses in jute.

Investigating Agroclimatic Feasibility of Kenaf/Maize Intercrop in Forest-Savannah Transition Zone of Southwest Nigeria

Agroclimatic feasibility of intercropping kenaf with maize in kenaf/maize mixtures was determined. Tainung1, Ifeken400, DMR-LSR-Y, Tainung1/DMR-LSR-Y and Ifeken400/DMR-LSR-Y were randomized in a complete block design with three replicates in a field trial during the early planting season of 2007. The phenological stages of each of the crops formed the basis of investigation. Selected agrometeorological variables were measured daily. The distribution of the thermal indices, temperature and photoperiod were optimal for kenaf growth. Mean soil temperatures of 31.5oC at planting encouraged over 80% of seed emergence. Mean air temperature fall within the temperature requirement for kenaf. During the phenological stages of kenaf and maize, the mean air temperature was adequate especially during the thermal sensitive stages. The fact that the mean relative humidity fall within the recommended values, insect pests attack occurred at the early stage of the vegetative period. On the basis of distribution of rainfall (827.4mm) and actual water availability (591.0mm) in relation to water requirement of kenaf (236.4mm), moisture indices were found to be optimum. Both the mean bast fibre yield and seed yield of Tainung1 were higher than Ifeken400 but no significant difference (P<0.05). Results also showed that the pattern of cropping system have effect on the yield components, as the yield of sole-planted kenaf was significantly (P<0.05) higher than the kenaf/maize intercropped. The grain yield recorded for sole-planted maize also indicated significant effect of cropping system. The results suggested that the study area supports the cultivation of kenaf/maize intercrop. Keywords: Agrometeorological variables, intercropping, kenaf/maize, phenological stages