Cultivated Jute Species Research Articles

Day-neutral jute plant: a hallmark for developing new jute genotype

Jute has more than 100 globally distributed species and is well known for its bast fibre biogenesis as well as its nutritional and medicinal properties. Unfortunately, year-round jute cultivation is highly limited due to its photosensitive character. Therefore, this study was carried out to analyse the flowering behaviour of selected cultivated jute species and their wild relatives to support the year-round supply of jute vegetables. A total of eight jute genotypes viz., Merha red, Merha green, Merha pink, Birol red, Birol green, Birol pink, BJRI deshi pat shak-1, and BINA pat shak-1 were examined, with the latter two selected as controls. In most cases, the six wild species had more surviving plants per unit area, better plant height, and more leaves and branches compared with controls. The highest stem base diameter, leaf area, leaf dry weight, and shoot dry weight were recorded in the control species. Days to 1st flowering, days to average flowering, and days to seed maturity were significantly earlier in wild species compared with the controls, indicating the existence of photo-insensitive characters. The desired vegetative and reproductive properties with high heritability and genetic variability can likely be transmitted from wild germplasm to cultivated jute species through crossing to produce a photo-insensitive jute variety.

Volatile organic compounds mediated non-preference for oviposition and feeding of hairy caterpillar, Spilosoma obliqua Walker (Lepidoptera: Erebidae) in jute

Aim: To identify the volatile organic compounds (VOCs) from wild and cultivated jute species imparting varying degree of non-preference for oviposition and feeding to jute hairy caterpillar, S. obliqua Walker. Methodology: Different host species of S. obliqua viz., Corchorus olitorius, C. aestuans, C. pseudo-olitorius, C. fascicularis, C. tridens and C. trilocularis were used to find out the feeding and oviposition preference of S. obliqua. Headspace volatiles were collected from different genotypes of jute and the chemical analysis was done with Gas chromatography - Mass Spectrometry (GC-MS). Results: The chemical compounds of VOCs responsible for causing non-preference mechanism of host plant selection to S. obliqua. The chemical complexity and chemistry of volatiles from cultivated and wild jute species indicated significant variation. The VOCs identified in C. aestuans was comparatively more than cultivated species and were different from other cultivated and wild species of jute. Very low preference index for larval feeding and oviposition preference of S. obliqua was due to the possible deterrent effect of volatile organic compounds. Interpretation: The GC-MS analysis of VOCs from C. aestuans (WCIN-179) indicated strong repellent action on S. obliqua that makes it resistant due to non-preference mechanism resulting in less preference for egg laying and feeding. The uniqueness and novelty of C. aestuans confirmed on the basis of very unique VOCs profile which makes it resistant against S. obliqua through multiple mechanisms, i.e., antibiosis and non-preference recording least suitable for egg laying, biology and growth of insects. Key words: GC-MS, Hairy caterpillar, Jute, Oviposition, Volatile Organic Compounds

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.

Genome-wide investigation of aquaporin genes in Corchorus spp and their role in organ development and abiotic stress tolerance

Aquaporins (AQPs), which are an essential type of membrane proteins, play roles in plant growth and stress tolerance by acting as channels for water homeostasis and nutrient uptake. These membrane proteins are important for the survival of different plant species under changing climates. However, the functional involvement of AQPs in jute is still unexplored. We conducted a genome-wide investigation into two cultivated jute species and identified 33 CoAQP and 31 CcAQP genes in the Corchorus olitorius and C. capsularis genomes, respectively. In both species, AQPs were classified into five phylogenetic subfamilies (PIPs, NIPS, SIPs, TIPs, and XIPs). Functional prediction of conserved NPA motif, ar/R selectivity filters, and Froger's position identified diversity in substrate specificity within the subfamilies of Jute AQPs. Investigation on putative cis-regulatory motifs revealed an enrichment of light, defense and stress responsiveness cis-element in the promoter regions. RNA-seq analysis showed the expression pattern of Co and CcAQPs under abiotic stresses and in organ development. Among the AQP genes, three (NIP6–1, SIP1–1, TIP4–1) were highly expressed in fiber cells, three (PIP1–1, PIP1–2, PIP2–1) in stem and leaf, and one (NIP7–1) in flower of both species. There were differential levels of expression patterns in response to salinity, drought, and waterlogging. In both species, two genes (XIP-1-1 and PIP1–3) showed a decreased level of expression with the increased level of waterlogging. Six AQPs (PIP1–1, PIP1–3, PIP2–1, NIP1–2 along with CcSIP1–2 and CoSIP2–1) showed upregulation under salt stress. On the other hand, two genes, PIP1–3 and PIP2–1, were overexpressed under drought stress. Results from this study provided detailed insights into the complexities of jute AQPs and their biological functions in adaptation, which can be useful for future varietal development programs.

Determination of β-carotene in jute leaves by spectrophotometry and thin layer chromatography

β-carotene is a carotenoid pigment that converts to vitamin A in human body and plays crucial role in visual functions, reproductive performance and immune system. Jute leaves contain β-carotene but amounts in different varieties of jute leaves are not known. The study was undertaken to estimate the β-carotene content in fresh jute leaves of the cultivated jute species Corchorus olitorius L. and Corchorus capsularis L. by spectrophotometry and thin layer chromatography. β-carotene content varies in leaves of different varieties of two species. Leaves of some C. olitorius variety showed higher amount of β-carotene than the leaves of C. capsularis variety. Some varieties of C. olitorius showed similarity with some varieties of C. capsularis. Variety Robi-1 of C .olitorius showed the highest content of β-carotene 39.93mg/100g. O-72, O-4, O-3820, O-9897 and OM-1 of olitorius variety showed higher β-carotene than all the varieties of C. capsularis. JRO-524 and MG-1 of C. olitorius variety is comparable to CVL-1, D-154, BJC-2197 and deshi pat shak-1 variety of C. capsularis regarding β-carotene content. Lowest β-carotene was estimated 12.55mg/100g in O-795 of olitorius variety and 12.32mg/100g in BJC-83 and 11.34mg/100g in BJC-2142 of capsularis variety. Thin layer chromatography system silica gel on TLC Al foils as stationary phase and hexane as mobile phase performs good separation and identification of β-carotene in jute leaves.

Reference genomes of the two cultivated jute species.

SummaryCultivated jute, which comprises the two species Corchorus capsularis and C. olitorius, is the second most important natural fibre source after cotton. Here we describe chromosome‐level assemblies of the genomes of both cultivated species. The C. capsularis and C. olitorius assemblies are each comprised of seven pseudo‐chromosomes, with the C. capsularis assembly consisting of 336 Mb with 25,874 genes and the C. olitorius assembly containing 361 Mb with 28 479 genes. Although the two Corchorus genomes exhibit collinearity, the genome of C. olitorius contains 25 Mb of additional sequences than that of C. capsularis with 13 putative inversions, which might give a hint to the difference of phenotypic variants between the two cultivated jute species. Analysis of gene expression in isolated fibre tissues reveals candidate genes involved in fibre development. Our analysis of the population structures of 242 cultivars from C. capsularis and 57 cultivars from C. olitorius by whole‐genome resequencing resulted in post‐domestication bottlenecks occurred ~2000 years ago in these species. We identified hundreds of putative significant marker‐trait associations (MTAs) controlling fibre fineness, cellulose content and lignin content of fibre by integrating data from genome‐wide association studies (GWAS) with data from analyses of selective sweeps due to natural and artificial selection in these two jute species. Among them, we further validated that CcCOBRA1 and CcC4H1 regulate fibre quality in transgenic plants via improving the biosynthesis of the secondary cell wall. Our results yielded important new resources for functional genomics research and genetic improvement in jute and allied fibre crops.

Jute leaves: A potential sources of lycopene

ABSTRACT Jute (Corchorus sp.) leaves may contain lycopene, a strong antioxidant, but amounts in jute leaves are not known. The study was undertaken to estimate the lycopene content in fresh, processed, and preserved jute leaves of the cultivated jute species C. olitorius L. and C. capsularis L. The highest lycopene content was in 45-day-old fresh leaves which gradually decreased with increasing plant age. Among processing methods, leaves soaked in vinegar had the highest lycopene for C. olitorius but in C. capsularis the highest lycopene was in leaves boiled with water and salt for 15 min. All the processing methods led to increased availability of lycopene compared to fresh leaves. Preserved jute leaves retained lycopene following drying and preservation at −20°C. The highest lycopene was from cold dried preserved leaves at 4°C and then air dried leaves at 33–35°C; the lowest lycopene content was from leaves dried in an oven at 100°C. Lycopene content in leaves differed due to plant ages. Lycopene in 45-day-old plant jute leaves was more than doubled compared to fresh red tomatoes. Further evaluation is needed to determine if consumption and digestion affect the available lycopene content in jute leaves available to humans.

Nutritional composition of some jute genotypes as vegetables

ABSTRACT Jute (Corchorus sp.) is consumed as a leafy vegetable in many parts of the world. There is little information on nutritional composition of cultivated jute species and their wild relatives. To determine nutritional components of jute leaf, 3 C. capsularis L., germplasm, ‘Merha red’, ‘Merha green’, ‘Birol red’, a C. olitorius L., ‘Accession-3840ʹ, and ‘BJRI deshi pat shak-1ʹ and ‘BINA pat shak-1ʹ were examined, with the latter 2 as controls. In most cases, the four wild species contained more vitamins and minerals, and had more surviving plants per unit area, compared with controls. The highest percent protein and ash, highest leaf area, and most leaves per plant, were in the controls. The desired biochemical properties with high heritability and genetic advance can likely be transmitted from wild germplasm to cultivated C. capsularis species through crossing, but evaluation in other agro-climatic regions is needed to determine the efficacy of wild germplasm as donor parent.

The Development of Macrophomina phaseolina (Fungus) Resistant and Glufosinate (Herbicide) Tolerant Transgenic Jute.

The worldwide demand for natural bast fibers is met aptly by the long, golden and silky fibers of jute. This highest bast fiber producing crop is of great applicability and is extensively used in paper and textile industry. Macrophomina phaseolina (Tassi) Goid is a severely devastating necrotrophic fungal pathogen causing stem rot, root rot, and charcoal rot diseases in both the cultivated species of jute – Corchorus capsularis and Corchorus olitorius. Another major problem faced in jute cultivation is profuse weed infestation in the fields. Huge losses in quality fiber production is caused by this pathogenic fungi and cultivation cost increases as well due to weed management expenditure during cropping season. To solve these long persisting jute cultivation challenges, the chitinase (chi11) gene (to provide fungus resistance) and the bar gene (to provide herbicide tolerance) have been incorporated in C. capsularis JRC-321 via Agrobacterium transformation and analyzed up to T2 generation. Stable integration and expression of these two genes in the jute genome was confirmed upon extensive analyses. Transgenic plants showed higher chitinase expression and chitin degrading activity than non-transgenic control plants. Antifungal activity significantly increased in transgenic plants as confirmed by detached leaf and whole plant M. phaseolina bioassay. Herbicide tolerance was analyzed by growing transgenic plants in 10 mg/l glufosinate ammonium containing media and by spraying 0.25% (v/v) glufosinate herbicide Basta® on them. Assessment of residual phytotoxicity effects of Basta® on soil confirmed no negative impact on growth of indicator plants corn and cucumber. Transgenic jute plants were at par with non-transgenic (control) jute plants in all phenotypic aspects. Non-transgenic (control) jute plants suffered significant losses in fiber yield and quality due to M. phaseolina infection whereas the transgenic lines maintained the quality of fiber even after the infection.

De novo transcriptome sequencing of two cultivated jute species under salinity stress.

Soil salinity, a major environmental stress, reduces agricultural productivity by restricting plant development and growth. Jute (Corchorus spp.), a commercially important bast fiber crop, includes two commercially cultivated species, Corchorus capsularis and Corchorus olitorius. We conducted high-throughput transcriptome sequencing of 24 C. capsularis and C. olitorius samples under salt stress and found 127 common differentially expressed genes (DEGs); additionally, 4489 and 492 common DEGs were identified in the root and leaf tissues, respectively, of both Corchorus species. Further, 32, 196, and 11 common differentially expressed transcription factors (DTFs) were detected in the leaf, root, or both tissues, respectively. Several Gene Ontology (GO) terms were enriched in NY and YY. A Kyoto Encyclopedia of Genes and Genomes analysis revealed numerous DEGs in both species. Abscisic acid and cytokinin signal pathways enriched respectively about 20 DEGs in leaves and roots of both NY and YY. The Ca2+, mitogen-activated protein kinase signaling and oxidative phosphorylation pathways were also found to be related to the plant response to salt stress, as evidenced by the DEGs in the roots of both species. These results provide insight into salt stress response mechanisms in plants as well as a basis for future breeding of salt-tolerant cultivars.

Development of a set of SSR markers for genetic polymorphism detection and interspecific hybrid jute breeding

Corchorus capsularis (white jute) and C. olitorius (dark jute) are the two principal cultivated species of jute that produce natural bast fiber of commercial importance. We have identified 4509 simple sequence repeat (SSR) loci from 34,163 unigene sequences of C. capsularis to develop a non-redundant set of 2079 flanking primer pairs. Among the SSRs, trinucleotide repeats were most frequent (60%) followed by dinucleotide repeats (37.6%). Annotation of the SSR-containing unigenes revealed their putative functions in various biological and molecular processes, including responses to biotic and abiotic signals. Eighteen expressed gene-derived SSR (eSSR) markers were successfully mapped to the existing single-nucleotide polymorphism (SNP) linkage map of jute, providing additional anchor points. Amplification of 72% of the 74 randomly selected primer pairs was successful in a panel of 24 jute accessions, comprising five and twelve accessions of C. capsularis and C. olitorius, respectively, and seven wild jute species. Forty-three primer pairs produced an average of 2.7 alleles and 58.1% polymorphism in a panel of 24 jute accessions. The mean PIC value was 0.34 but some markers showed PIC values higher than 0.5, suggesting that these markers can efficiently measure genetic diversity and serve for mapping of quantitative trait loci (QTLs) in jute. A primer polymorphism survey with parents of a wide-hybridized population between a cultivated jute and its wild relative revealed their efficacy for interspecific hybrid identification. For ready accessibility of jute eSSR primers, we compiled all information in a user-friendly web database, JuteMarkerdb (http://jutemarkerdb.icar.gov.in/) for the first time in jute. This eSSR resource in jute is expected to be of use in characterization of germplasm, interspecific hybrid and variety identification, and marker-assisted breeding of superior-quality jute.

Biochemical Effects of Cultivated and Wild Jute Species on Life Stages of the Broad Mite,Polyphagotarsonemus latus(Prostigmata: Tarsonemidae)

Abstract We studied the life cycle of the broad mite, Polyphagotarsonemus latus (Banks) (Prostigmata: Tarsonemidae), on 2 cultivated jute species (Corchorus olitorius L. and Corchorus capsularis L.; Malvales: Malvaceae) and 5 wild species (Corchorus aestuans L., Corchorus pseudo-olitorius Islam & Zaid, Corchorus fascicularis Lamarck, Corchorus tridens L., and Corchorus trilocularis L.) under laboratory conditions. Results showed that the egg incubation period, larval and nymphal durations, and adult male and female longevities of P. latus varied significantly on different jute species. The larval period (mean ± SD) was significantly shorter (57.00 ± 2.07 h) on C. olitorius than on C. fascicularis, C. aestuans, and C. tridens (68.00 ± 1.58 to 72.00 ± 1.30 h). The phenol content was greatest in C. trilocularis (61.92 ± 1.91 μg/g), and it was 16.26 ± 1.34 μg/g and 20.45 ± 1.43 μg/g in C. olitorius and C. capsularis, respectively. The polyphenol oxidase content was smallest in C. capsularis (0.99 ± 0.10 μg/mL...

Host Plant Resistance in Cultivated Jute and Its Wild Relatives Towards Jute Hairy CaterpillarSpilosoma obliqua(Lepidoptera: Arctiidae)

The oviposition, feeding behavior, and development of the jute hairy caterpillar Spilosoma obliqua Walker (Lepidoptera: Arctiidae) was studied on one cultivated jute species, Corchorus olitorius L. (‘JRO-204') (Malvales: Malvaceae), and 5 wild jute species, viz., C. tridens L., C. trilocularis L., C. pseudo-olitorius Islam & Zaid, C. aestuans L., and C. fascicularis Lamarck under laboratory conditions with a temperature of 27 ± 2 °C and relative humidity of 80 ± 5%. These host plant species had considerable influence on oviposition, larval feeding behavior, larval survival, larval weight, pupation, pupal weight, and adult emergence. Significant differences were observed in oviposition preference based on numbers of eggs laid by the adults. The mean number of egg clusters differed significantly with 3.6 ± 0.3, 3.0 ± 0.6, 3.3 ± 0.3, 3.0 ± 0.6, 1.0 ± 0.6, and 2.0 ± 1.2 on C. olitorius, C. fascicularis, C. trilocularis, C. pseudo-olitorius, C. tridens, and C. aestuans, respectively. The C. pseudo-olitorius and C. aestuans were less preferred with the lowest mean numbers of eggs per cluster (77.2 ± 8.2 and 75.2 ± 38.8, respectively) compared with 174.0 ± 2.7 on C. olitorius. With respect to feeding preferences, most larvae (53.9 ± 3.4%) preferred C. olitorius as compared with 1.6 ± 0.02% and 7.2 ± 1.5% of larvae feeding on C. aestuans and C. tridens, respectively. Only 2 species, namely C. trilocularis and C. olitorius, supported complete larval development. The growth of 3rd instars indicated a maximum antibiosis effect by C. tridens and C. aestuans on S. obliqua. Total protein content in the host plants had a significant positive correlation with the larval survival, weight, pupation, and adult emergence of S. obliqua, whereas polyphenol oxidase and total phenol were negatively correlated. The effect of wild jute species with higher phenol and peroxidase as host plants manifested adversely on larval development, growth, survival, pupation, and adult emergence, which indicates the antibiosis mechanism of resistance.

Comparative molecular cytogenetic analyses of a major tandemly repeated DNA family and retrotransposon sequences in cultivated jute Corchorus species (Malvaceae)

The cultivated jute species Corchorus olitorius and Corchorus capsularis are important fibre crops. The analysis of repetitive DNA sequences, comprising a major part of plant genomes, has not been carried out in jute but is useful to investigate the long-range organization of chromosomes. The aim of this study was the identification of repetitive DNA sequences to facilitate comparative molecular and cytogenetic studies of two jute cultivars and to develop a fluorescent in situ hybridization (FISH) karyotype for chromosome identification. A plasmid library was generated from C. olitorius and C. capsularis with genomic restriction fragments of 100-500 bp, which was complemented by targeted cloning of satellite DNA by PCR. The diversity of the repetitive DNA families was analysed comparatively. The genomic abundance and chromosomal localization of different repeat classes were investigated by Southern analysis and FISH, respectively. The cytosine methylation of satellite arrays was studied by immunolabelling. Major satellite repeats and retrotransposons have been identified from C. olitorius and C. capsularis. The satellite family CoSat I forms two undermethylated species-specific subfamilies, while the long terminal repeat (LTR) retrotransposons CoRetro I and CoRetro II show similarity to the Metaviridea of plant retroelements. FISH karyotypes were developed by multicolour FISH using these repetitive DNA sequences in combination with 5S and 18S-5·8S-25S rRNA genes which enable the unequivocal chromosome discrimination in both jute species. The analysis of the structure and diversity of the repeated DNA is crucial for genome sequence annotation. The reference karyotypes will be useful for breeding of jute and provide the basis for karyotyping homeologous chromosomes of wild jute species to reveal the genetic and evolutionary relationship between cultivated and wild Corchorus species.

Xyloglucan endotransglycosylase/hydrolase genes from a susceptible and resistant jute species show opposite expression pattern following Macrophomina phaseolina infection

Two of the most widely and intensively cultivated jute species, Corchorus capsularis and Corchorus olitorius, suffer severely from a stem rot disease caused by the fungus Macrophomina phaseolina. Wild jute species, C. trilocularis, shows resistance to this pathogenic fungus. In this study, the technique of differential display was applied to identify genes which are differentially expressed, under both infected and un-infected conditions, between C. trilocularis and C. olitorius var O-72. Two xyloglucan endotransglycosylase/hydrolase (XTH) genes designated CoXTH1 (from Corchorus olitorius) and CtXTH1 (from C.trilocularis) were identified from each of the two species which show different expression patterns upon fungal infection. A steady rise in the expression of CtXTH1 in response to infection was observed by quantitative real time PCR whereas the expression of CoXTH1 was found to be downregulated. Full length sequences of these two genes were determined using primer based gene walking and RACE PCR. This study confirms the involvement of XTH in molecular interactions between M. phaseolina and jute. However, it remains to be explored whether XTH is an essential component of the signaling pathway involved in plant-fungal interaction.

Origins of white (Corchorus capsularis L.) and dark (C. olitorius L.) jute: a reevaluation based on nuclear and chloroplast microsatellites

Using a suite of morphological traits and neutral molecular markers, we have reevaluated the origins of the two cultivated jute species. The nine Corchorus species, which are restricted to both Africa and Asia, were phenotyped for bast fibre yield- and quality-linked traits, morpho-phenetically classified based on those traits’ similarities, genotyped by nuclear microsatellites and haplotyped by chloroplast microsatellites. The two cultivated jute species contain ~70% of the neutral genetic diversity present in their wild relatives. Phylogenetic analyses using 38 highly polymorphic nuclear microsatellites identified C. aestuans as the common ancestor to both the cultivated jute species. C. urticifolius is the nuclear progenitor of C. olitorius (dark jute), but no close nuclear progenitor of C. capsularis (white jute) could be identified. Although either C. aestuans or C. pseudo-olitorius or both appear to be the possible cytoplasmic progenitors of white jute, the matrilineal ancestry of dark jute remains obscure. However, the presence of a single, unique chloroplast haplotype in each of the two cultivated species indicates the involvement of other unknown wild relatives. Taken together with archaeobotanical evidence, our results suggest that dark jute had its origin in equatorial region of east Africa, but was domesticated in India. We could not support an Indo-Myanmar origin of white jute, and possibly it also originated in Africa, but was domesticated in Asia.

First nuclear DNA amounts in diploid (2n = 2x = 14) Corchorus spp. by flow cytometry: genome sizes in the cultivated jute species (C. capsularis L. and C. olitorius L.) are ∼300% smaller than the reported estimate of 1100–1350 Mb

We report the 2C values (nuclear DNA content) and haploid genome (1C) sizes of the Corchorus species (2n = 2x = 14), with a special reference to the two cultivated jute species, viz., C. capsularis L. (the white jute) and C. olitorius L. (the tossa jute). Flow cytometric analysis of propidium iodide-stained nuclei showed that the 2C values were between 0.502 and 0.695 pg for C. capsularis, and between 0.643 and 0.718 pg for C. olitorius. For both the cultivated species, however, mutants had higher amounts of nuclear DNA than that of the cultivars. Amongst the wild Corchorus species, the lowest 2C value was observed in C. fascicularis (0.384 pg), while the highest in C. pseudo-olitorius (0.712). The current 2C values of both the cultivated jute species are in disagreement with earlier estimates of 2.3 and 2.8 pg in C. capsularis and C. olitorius, respectively. Of the Corchorus species studied, C. fascicularis has the smallest haploid genome (~188 Mb) followed by C. aestuans (~194 Mb). Our results show that, on an average, genome sizes (1C values) of C. capsularis and C. olitorius are ~280 Mb and ~324 Mb, respectively, which are ~300% smaller than their corresponding reported estimates. The white jute cv. JRC-212 (or Branca) has the smallest genome (~246 Mb) among the economically important crop species.

Analysis of Genetic Diversity in Cultivated Jute Determined by Means of SSR Markers and AFLP Profiling

Genetic improvement of the cultivars of jute (Corchorus olitorius L. and Corchorus capsularis L.) is needed to broaden the genetic base of new cultivars. All the cultivars in use have been evolved through pure line selection from a few common accessions. The objective of this study was to evaluate the genetic diversity available in the cultivated species of jute. Genetic diversity was evaluated by simple sequence repeat (SSR) marker loci and an AFLP assay. A total of 305 polymorphic products were detected by AFLP analysis using 10 pairs of primers (EcoRI and MseI) to amplify template DNA from 49 genotypes of the two jute species. Additionally, polymorphism with two to four allelic lengths was detected with each pair of chloroplast microsatellite primers developed from Nicotiana tabacum L. Results from both evaluations showed that the level of variation between species is high. The two species indeed are distantly related and their maternal origins may be different. On the contrary, genetic variability present at the intraspecific level is low. The resulting dendrogram showed common ancestral origin for many accessions. A few major Indian cultivars of both the species, used as an internal check, were closely related to the wild accessions. Nevertheless, RG, an Indian accession and two Kenyan accessions, KEN/BL/17 and KEN/DS/35C, among the C. olitorius genotypes and CHN/FJ/69 of C. capsularis revealed phenetic distinctiveness from the rest of the genotypes studied. The results indicate that enough diversity exists to broaden the genetic base of new jute cultivars.

Analysis of Genetic Diversity in Cultivated Jute Determined by Means of SSR Markers and AFLP Profiling

Genetic improvement of the cultivars of jute (Corchorus olitorius L. and Corchorus capsularis L.) is needed to broaden the genetic base of new cultivars. All the cultivars in use have been evolved through pure line selection from a few common accessions. The objective of this study was to evaluate the genetic diversity available in the cultivated species of jute. Genetic diversity was evaluated by simple sequence repeat (SSR) marker loci and an AFLP assay. A total of 305 polymorphic products were detected by AFLP analysis using 10 pairs of primers (EcoRI and MseI) to amplify template DNA from 49 genotypes of the two jute species. Additionally, polymorphism with two to four allelic lengths was detected with each pair of chloroplast microsatellite primers developed from Nicotiana tabacum L. Results from both evaluations showed that the level of variation between species is high. The two species indeed are distantly related and their maternal origins may be different. On the contrary, genetic variability present at the intraspecific level is low. The resulting dendrogram showed common ancestral origin for many accessions. A few major Indian cultivars of both the species, used as an internal check, were closely related to the wild accessions. Nevertheless, RG, an Indian accession and two Kenyan accessions, KEN/BL/17 and KEN/DS/35C, among the C. olitorius genotypes and CHN/FJ/69 of C. capsularis revealed phenetic distinctiveness from the rest of the genotypes studied. The results indicate that enough diversity exists to broaden the genetic base of new jute cultivars.

DNA fingerprinting of jute germplasm by RAPD.

The genotype characteristic of cultivars was investigated, along with varieties of both of the jute species, Corchorus olitorius and Corchorus capsularis, in the germplasm collection at the Bangladesh Jute Research Institute (BJRI). DNA fingerprinting was generated for 9 different varieties and 12 accessions of jute cultivars by using random amplified polymorphic DNA (RAPD). A total of 29 arbitrary oligonucleotide primers were screened. Seven primers gave polymorphism within the varieties, and 6 primers detected polymorphism within the accessions that were tested. A dendrogram was engendered from these data, and this gave a distinct clustering of the cultivated species of jute. Therefore, we generated RAPD markers, which are species-specific. These primers can distinguish between C. olitorius and C. capsularis. From the dendrogram that we generated between the various members of these two species, we found the existing genetic classification that agrees with our molecular marking data. A different dendrogram showed that jute accessions could be clustered into three groups. These data will be invaluable in the conservation and utilization of the genetic pool in the germplasm collection.