Bast Fiber Crops Research Articles

Genome-Wide Analysis of the Nramp Gene Family in Kenaf (Hibiscus cannabinus): Identification, Expression Analysis, and Response to Cadmium Stress.

Kenaf (Hibiscus cannabinu) is a grass bast fiber crop that has the ability to tolerate and accumulate heavy metals, and it has been considered as a potential heavy metal accumulator and remediation plant. Nramp is a natural resistance-related macrophage, which plays an important role in the transport of divalent metal ions, plant growth and development, and abiotic stress. In this study, the Nramp gene family of kenaf was analyzed at the whole genome level. A total of 15 HcNramp genes were identified. They are distributed unevenly on chromosomes. Phylogenetic analysis classified 15 HcNramp proteins into 3 different subfamilies. All proteins share specific motif 4 and motif 6, and the genes belonging to the same subfamily are similar in structure and motif. The promoters are rich in hormone response, meristem expression, and environmental stress response elements. Under different treatments, the expression levels of HcNramp genes vary in different tissues, and most of them are expressed in roots first. These findings can provide a basis for understanding the potential role of the Nramp gene family in kenaf in response to cadmium (Cd) stress, and are of great significance for screening related Cd tolerance genes in kenaf.

Retting of Bast Fiber Crops Like Hemp and Flax—A Review for Classification of Procedures

The interest and thus the number of publications on the supply chains of bast fiber plants has steadily increased in recent years. A number of specific technical terms related to methods and their use for individual areas of the supply chain are often interpreted and used in very different ways. Therefore, the aim of this publication is to increase the clarity of the description of the operations and to improve the understanding of the sequence and the purpose of the process steps. This is based on a selected review of the relevant literature as well as on suggestions for their classification

Chemical composition of fiber and shive in bast-fiber crops and the products of their alkaline delignification

The present article examines the chemical composition of fiber and shive from fiber flax and hemp obtained in Russia under industrial conditions, as well as that of the products of their alkaline delignification. Alkaline delignification was carried out at atmospheric pressure with a 4% sodium hydroxide solution; the chemical composition was determined via wet analysis. The chemical composition of hemp shive from Russian producers was studied for the first time. In the studied objects, the mass fraction of cellulose was found to range from 42.3 to 66.1%, and after alkaline delignification, the yield of products reached 47.0–50.0%. The behavior of fiber flax and hemp fiber is similar during alkaline delignification: cellulose content increases by 1.2–1.3 times, pentosan content decreases by 4.3–6.3 times, and lignin content is virtually the same. The behavior of fiber flax and hemp shive is dramatically different during alkaline delignification. The shive of fiber flax is resistant to alkaline delignification: cellulose content increases by 1.4 times, pentosan content decreases by 4.2 times, and lignin content increases by 1.4 times, which is due to the nature of lignin. Hemp shive is easily alkaline delignified: cellulose content increases by 1.8 times; the content of pentosans decreases by 5.8 times, and lignin content decreases by 2.2 times; the product of alkaline delignification contains cellulose (87.3%), pentosans (5.4%), and lignin (8.2%). The use of hemp shive for chemical and biotechnological transformation is expected to have high prospects.

Method of ISSR-marking in the study of genetic diversity of flax varieties

The genetic diversity of crop varieties should be assessed using modern molecular markers. One of the most promising and simple methods of plant genetic analysis is intermicrosatellite labeling (ISSR). The purpose of this research is to study the polymorphism of varieties of fiber flax and linseed flax included in the State Register of Breeding Achievements of the Russian Federation, as well as local forms of fiber flax using ISSR markers. The objects for the research were 83 samples from the collection of the Federal Research Center for Bast Fiber Crops, among them 24 varieties of linseed flax, 56 varieties of fiber flax of domestic and foreign breeding, and three local forms from the Central Non-Black Earth Region. Genetic analysis was carried out by PCR method using a set of 25 ISSR primers. Detection of amplification products was carried out using electrophoresis in 1.5% agarose gel. Based on intraspecific selection of flax varieties to oilseed and fiber forms, a cluster analysis was performed according to the results of ISSR labeling independently in each of two groups that allowed to increase the reliability of conclusions on the existing dependences. Dendrograms of the genetic similarity of the studied samples of linseed flax and fiber flax were studied independently from each other. As a result of the analysis, linseed flax varieties were divided into five clusters, which made it possible to establish dependencies related to their origin (originator of the variety) and oil content in the seed. The dendrogram which included varieties of fiber flax and its local forms, revealed twelve subclusters forming three uneven groups. Almost every group had its own characteristic feature, not related to the geography of origin. The grouping of varieties occurred mainly on the basis of their various characteristics in terms of flax fiber content, ripening time and resistance to environmental stress factors. The results of the research show the applicability of using the ISSR-markers as a valid and accessible method for developing the elements of marker-associative breeding of bast fiber crops.

Variability and interrelation of breeding-valuable traits of varieties and lines of spring soft wheat in the conditions of the Middle Volga region

The article presents the results of a three-year study (2020-2022) of 16 varieties and 17 breeding lines of spring soft wheat bred by the Federal Scientific Center for Bast Fiber Crops in the soil and climatic conditions of the Penza region. The crop productivity in the experiment varied between 1.77-4.15 t/ha. Seven samples demonstrated the highest productivity: Nastavnik, Eritrospermum 70/04-3, Irvita, Sensei, Eritrospermum 20/08-7, Lutestsens 1/12-19, Eritrospermum 15/08-4, which exceeded the standard variety Arkhat by 0.27-0.71 t/ha. During the studies the yield was related to the average variable trait (CV =11.9-19.5 %). The variation of the duration of the growing season of the studied spring wheat samples averaged 81-93 days. It was shorter in 2021 (from 67 to 80 days), the longest in 2022 (from 91 to 100 days). The height of spring soft wheat plants in the studies was a low-variable feature (CV = 3.4-8.5 %) and averaged 82.1-100.2 cm over the years. The ear grain content varied from 18 pieces in the Erythrospermum 25/08-11-18 in 2022 up to 40 pieces in the Nastavnik variety in 2021. The trait was medium-variable (CV = 11.3-18.5 %). The highest average productivity of an ear was noted in 2022 – 1.08 g, and the lowest in 2020 – 0.92 g. The high mass of grain per ear was noted in Nastavnik variety – 1.40 g, Eritrospermum 70/04-3 – 1,38 g, Irvita – 1.35 g, which were characterized by high yield. Eritrospermum 70/04-3, Eritrospermum 20/08-7 and Irvita selected by the genotype productivity were characterized by bulky grains of 40.6-43.2 g. A significant correlation was observed between the yield and the grain weight per plant (r = 0.908...0.924, P≤0.001). The studied patterns can be used in ecological breeding of soft spring wheat.

De novo transcriptome of a bast fibre crop Crotalaria juncea reveals T2 ribonuclease genes to investigate late-acting self-rejection of pollens

The biology of gametophytic late-acting self-rejection of pollen in pre-zygotic ovules is relatively unknown in the Fabaceae family of plants. Our understanding of the genetic basis of late-acting self-incompatibility (LSI) is limited due to a lack of sequence data and candidate genes. Crotalaria juncea, a Fabaceae family member that produces commercially important phloem fiber, possesses LSI. Due to a lack of selfed seeds, it is difficult to maintain genetic purity in germplasm and develop breeding lines for improved fiber quality and yield. To investigate candidate genes for LSI in C. juncea, a high-quality de novo transcriptome was generated. It facilitated the identification of genes from the self-incompatibility-related ribonuclease (RNase) family, specifically a Class III T2/RNase gene with sequence properties similar to S-RNase proteins. Based on conserved amino acid motifs, histidine residues, and a high isoelectric point (pI ≥9.0), Cjun_RNS3.1 was identified as an S-RNase homologue (non-S-RNase) or relic S-RNase gene. Unlike typical S-RNases found in known SI plant systems, evolutionary analysis of the Cjun_RNS3.1 protein revealed its ancestral origin. The expression of Cjun_RNS3.1 and other T2/RNase genes revealed differential expression patterns in the pistils of LSI and self-compatible Crotalaria species. The upregulation of the Cjun_RNS3.1 gene during the different stages of pollen tube development indicates that it may be involved in the LSI. In summary, the sunn hemp transcriptome is the first genomic resource reported from a Fabaceae family plant with the LSI trait. A non-S-RNase gene with an ancestral evolutionary origin and a diverse function was found, which could be related to gametophytic LSI. This could be used as a model system to investigate the molecular basis of LSI in the Fabaceae family and help develop C. juncea breeding lines for fibre improvement.

Variety agrotechnology for cultivation of spelled varieties Pskovityanka

The influence of the main agricultural practices on the yield and its structure of spring wheat spelled variety Pskovityanka when cultivated on soddy-podzolic soil was studied. The studies were carried out in 2019–2020 on the fields of the FSBSI Federal Research Center for Bast Fiber Crops of the Pskov. Experimental options included three factors: levels of mineral fertilizers - control (without fertilizer), N60P60K60, N90P90K90, N120P120K120; seeding rates - 4, 5 and 6 million germinating seeds/ha; sowing dates - I and II decade of May. Studies have shown that the largest weight of 1000 grains - 37.5 and 37.7 g - was obtained when sowing emmer in the second decade of May with a seeding rate of 5 and 6 million units/ha against the background of applying mineral fertilizers at a dose of N90P90K90. On average, over the years of research, according to the variants of the experiment, from 16.5 to 25.8 q/ha of spelled grain was obtained. It has been established that the most effective factor is the use of mineral fertilizers, which, in the studied doses, provided an additional 2.4 to 5.5 q/ha of grain according to the experimental options. The shift in the sowing date of spelt to the second decade of May made it possible to have a significant increase in yield from 2.2 to 4.0 q/ha of grain. Seeding rates turned out to be a less effective factor, an increase in which from 4 to 6 million units/ha contributed to an increase in grain productivity by 1.5–4.1 q/ha. The highest yield of spelled at the level of 25.1–25.8 q/ha was obtained when the crop was sown in the second decade of May with seeding rates of 5 and 6 million units per hectare against the background of mineral fertilizers N90P90K90.

Development and Application of EST-SSR Markers Related to Lead Stress Responses in Kenaf Based on Transcriptome Sequencing Data

Kenaf is an important bast fiber crop. In order to diversify the available kenaf simple sequence repeat (SSR) molecular markers and generate markers potentially useful for kenaf breeding, we developed expression sequence tag simple sequence repeat (EST-SSR) molecular markers based on lead-stressed kenaf transcriptome sequencing data and spliced unigene sequences. Additionally, the distribution of the SSRs in the transcriptome and the potential functions of the SSR-containing genes were determined. Moreover, SSR markers in the differentially expressed genes (DEGs) of a protein–protein interaction (PPI) network were analyzed to screen for polymorphic markers, which were used to examine the genetic diversity and population structure of kenaf germplasm resources. The genetic diversity and population structure of 138 kenaf germplasm materials revealed that 22 EST-SSR markers could be used to distinguish the kenaf germplasms. The 22 EST-SSR markers enrich the kenaf molecular markers database and provide an important tool for future genetic improvement of kenaf resistance to lead stress.

The influence of the seeding rate on the yield of flax of the Phoenix variety in the conditions of the Smolensk region

The article presents the results of scientific research for 2018-2020 to identify the reaction of the flax Phoenix variety (Linum usitatissimum L.) to increasing seeding rates. The experiment was laid on the sod-podzolic medium loamy soil of a separate subdivision of the Smolensk Research Institute of the Federal State Budget Research Institution «Federal Research Center for Bast Fiber Crops». It was found out that with an increase in the seeding rate, there was an increase in the number of flax stalks per 1 m2. However, the number of boxes per plant and seeds per box decreased by almost 1.2–1.6 times. The greatest resistance of flax plants to lodging (5.0 points) was obtained at seeding rates of 16, 18 and 20 million units/ha. Further, with an increase in the seeding rate, the studied indicator decreased to 3.8 points. The increase in the seeding rate was accompanied by a decrease in the yield of flax seeds by 0.35 t/ha (or 41%) and an increase in the yield of flax - by 1.91 t/ha (or 34%). Optimal in terms of flax fiber content and its yield were variants with a seeding rate of 22 and 24 million germinating seeds per 1 ha. The fiber content in plants in these variants was 28.0–27.4%, its yield was 20.0-20.7%.

Genetic Determinants of Fiber-Associated Traits in Flax Identified by Omics Data Integration.

In this paper, we explore potential genetic factors in control of flax phenotypes associated with fiber by mining a collection of 306 flax accessions from the Federal Research Centre of the Bast Fiber Crops, Torzhok, Russia. In total, 11 traits were assessed in the course of 3 successive years. A genome-wide association study was performed for each phenotype independently using six different single-locus models implemented in the GAPIT3 R package. Moreover, we applied a multivariate linear mixed model implemented in the GEMMA package to account for trait correlations and potential pleiotropic effects of polymorphisms. The analyses revealed a number of genomic variants associated with different fiber traits, implying the complex and polygenic control. All stable variants demonstrate a statistically significant allelic effect across all 3 years of the experiment. We tested the validity of the predicted variants using gene expression data available for the flax fiber studies. The results shed new light on the processes and pathways associated with the complex fiber traits, while the pinpointed candidate genes may be further used for marker-assisted selection.

Sui Generis Development of Molecular Markers from Transcriptome of Crotalaria juncea, a Fabaceae Family Bast Fiber Crop

ABSTRACT Lack of genomic resources in sunn hemp (Crotalaria juncea L.), a leguminous bast fiber crop, is one of the major constraints for germplasm characterization and genetic analysis. We identified non-redundant sets of a variety of molecular markers from the de novo flower-bud transcriptome of sunn hemp. These molecular markers included 1683 simple sequence repeats, 4759 intron length polymorphism markers primarily from protein-coding genes, and 3309 single nucleotide polymorphism allele-specific markers. All of these marker resources have been integrated into a simple database for easy access. To evaluate marker efficiency and polymorphism information content of the sampled primers, a subset of SSR and intron length polymorphism markers were validated in sunn hemp germplasm accessions to obtain average PIC values of 0.26–0.32. The SSR genotyping profiles also aided in the genetic distance matrix-based clustering of sunn hemp germplasm accessions. The ability of these molecular markers to successfully amplify in cross-genera bast fiber crops further demonstrated their effectiveness in genotyping. Thus, the current study describes the identification of previously undisclosed endogenous molecular markers in sunn hemp, which have potential applications in genetic studies and breeding in sunn hemp for bast fiber improvement.

Адаптивность лядвенца рогатого в Нечерноземье России

Abstract. The purpose of the research is to conduct a comparative study of lotus corniculatus samples with the Smolenskiy 1 standard, as well as with the average yield of green mass according to experience. It is necessary to identify the most productive and adapted to the conditions of the Smolensk region variety numbers for further transfer to the next stage of breeding study. The scientific novelty of the work lies in the fact that the results of adaptability in terms of green mass yield were studied for the first time in the breeding nursery of the Federal Research Center for Bast Fiber Crops on lotus corniculatus crops. Methods. The indices of plasticity (bi), stability (Sd2), genetic flexibility ((Ymin + Ymax)/2), stress resistance (Ymin – Ymax), coefficient of variation (V), coefficient of adaptability (CA), coefficient of equalization (E), yield range (d). The soil of the site is sod-medium podzolic with an average humus content of 2.3, P2O5 222–240 mg/kg, K2O 102–170 mg/kg of soil, salt extract pH 4.9–5,4. Weather and climatic conditions for 2017–2020 were different, so HTC 1,2–2,4; SAT 2200–2400 °C. Results. Of the 16 cultivars, the most productive were E-25 (59.3 t/ha) and E-49 (48.1 t/ha). The numbers E-8, E-11, Smolenskiy 1, E-6, E-9, E-50 and E-25 have increased stress resistance (–18.8 ...–28.8 t/ha). The best indicator of genetic flexibility is in E-25, E-10, E-16 (52.4 t/ha, 48.8 t/ha and 45.5 t/ha). The most plastic samples are E-19 (1.09), E-50 (1.05), E-16 and E-26 (1.02), E-6 (0.99). In the experiment, E-26 (6.27), E-47 (7.67), E-16 (8.43) and E-6 (8.47) are more stable. High adaptability was shown by E-25, E-11, E-10, E-49 with a coefficient of KA = 1.31...1.06. E-9, E-10, E-12, Smolenskiy 1, E-47, E-25, E-16, E-6 have good agronomic stability, E-26 with a coefficient E = 80.4...70.1%. A comprehensive analysis of the indicators made it possible to identify the most valuable lotus corniculatus cultivar for further reproduction and transfer to the next stage of breeding study: E-6, E-9, E-10, E-11, E-12, E-16, E-19, E-25, E-26, E-47, E-49.

Multi‐omics provides new insights into the domestication and improvement of dark jute ( Corchorus olitorius )

Jute (Corchorus sp.) is the most important bast fiber crop worldwide; however, the mechanisms underlying domestication and improvement remain largely unknown. We performed multi-omics analysis by integrating de novo sequencing, resequencing, and transcriptomic and epigenetic sequencing to clarify the domestication and improvement of dark jute Corchorus olitorius. We demonstrated that dark jute underwent early domestication and a relatively moderate genetic bottleneck during improvement breeding. A genome-wide association study of 11 important agronomic traits identified abundant candidate loci. We characterized the selective sweeps in the two breeding stages of jute, prominently, soil salinity differences played an important role in environmental adaptation during domestication, and the strongly selected genes for improvement had an increased frequency of favorable haplotypes. Furthermore, we speculated that an encoding auxin/indole-3-acetic acid protein COS07g_00652 could enhance the flexibility and strength of the stem to improve fiber yield. Our study not only provides valuable genetic resources for future fiber breeding in jute, but also is of great significance for reviewing the genetic basis of early crop breeding.

Productivity and quality of flax in the application of mineral fertilizers and folk fertilization of plants with the preparation Controlfit

Studies to assess the effect of foliar top dressing of flax with a silicon-containing preparation Controlfit were conducted on different backgrounds of mineral fertilizers in conditions of sod-podzolic medium loamy soil. The experiment was carried out in 2019-2021 on the field of a Separate subdivision of the Smolensk Research Institute of the Federal State Budget Research Institution – Federal Research Center for Bast Fiber Crops. The object of the study was a new variety of flax Phoenix, bred by Smolensk breeders. According to the results of the experiment, it was found that the yield of flax varied greatly over the years of the study, depending on weather conditions. On average, over 3 years of research, the highest yield of flax seeds was obtained on the variant with the maximum dose of mineral fertilizers N48P48K48 and amounted to 6.4 c/ha (83% of the control). Foliar top dressing with Controlfit did not change or even reduced the yield of flax seeds, as it led to the production of lighter seeds and fewer boxes on plants. The combined use of mineral fertilizers increased the yield of flax by 27-66%. The treatment of flax plants with the preparation Controlfit additionally increased the yield of straw by 31%. The effect of mineral fertilizers had a positive effect on the formation of long flax fiber, increasing its yield by 1.2 times relative to the control without fertilizers. Additional treatment of plants with Controlfit increased this indicator by 10-11%. The strength of flax fiber threads increased by 16% with an increase in the dose of mineral fertilizers and by 23% with the use of foliar fertilizing.

Assessment of Seed Yielding Potential of Sunnhemp (Crotalaria juncea) under Southern Plateau Zone of India

Background: Sunnhemp is an important bast fibre crop suitable for diversified uses. Recently, its cultivation has started expanding considerably throughout the world particularly for its potential usage in sustainable farming and in reducing use of synthetic fertilizers from agricultural system. Seed production and fibre production are mutually exclusive in sunnhemp because of different photo-period requirements for these purposes and destructive fibre extraction process. The major limitation in sunnhemp popularization cultivation is availability of seed. In this context, present study was undertaken to identify proper sowing time and suitable cultivars, and find correlation of seed yield with weather parameters for Telangana state of India. Methods: Three dates of sowing and six cultivars were tested in split-plot design over two years i.e., 2019-20 and 2020-21. Pooled data over two years were analyzed for important seed yield related traits. Result: The analysis of variance revealed significant influences of sowing dates, cultivars and their interaction on majority of the traits. Among three sowing dates, 2nd week of September was the best suited for seed yield and related traits. The cultivar SUIN 037 recorded maximum seed yield followed by SUIN 053. Among different combinations of treatment, the cultivars SUIN 037 and SH 4 sown during 2nd week of September resulted in maximum and comparable seed yield. The correlation and regression studies showed that the weather parameters had significant influences on yield attributes of sunnhemp.

Effects of traditional field retting of hemp on soil organic carbon and the soil microbial community

AbstractRetting is a process used with bast fiber crops such as industrial hemp (Cannabis sativaL.) to expedite the separation of fibers from the woody core of the stalk. Field retting involves partial decomposition of stalks on the soil surface and is facilitated by soil microorganisms. Effects of field retting on soil C have not been studied, and little information is available on how field retting affects the soil microbial community. We conducted an experiment to investigate effects of field retting on total organic soil C (TOC), permanganate oxidizable soil C (POXC), and relative abundance of microbial fatty acid methyl ester biomarkers (FAMEs). Four treatments were imposed: (a) no retting (NR), (b) low‐density retting (LDR) (2,500 kg stalks ha–1), (c) high‐density retting (HDR) (5,000 kg stalks ha–1), and (d) control (CON). The NR, LDR, and HDR treatments were conducted on plots where hemp was grown, whereas the CON treatment excluded production and retting. Plots under HDR treatment generally had greater TOC and POXC than plots where no retting occurred. Analysis of FAMEs indicated that soil microbial communities were grouped according to retting treatments. Greater fungal abundance and higher fungi to bacteria ratios were associated with soils where retting occurred. Compared with retting methods where harvested stalks are immediately removed from the field, field retting may mitigate soil C losses associated with harvest and may be a useful component of maintaining soil health when used in concert with management practices that build soil C.

Genetic specificity of high milk productive Brown Swiss cows

There were studied the genetic characteristics of longevity cows of the Brown Swiss breed of the breeding reproducer of ZAO im. Michurin using immunogenetic monitoring. The research in the laboratory of zootechnologies of the Smolensk Research Institute of the Federal Research Center for Bast Fiber Crops was carried out in accordance with generally accepted methods. The duration of productive life of cows was, on average, 6 lactations with lifetime milk productivity of 27,000 kg of milk with a fat content of 3.88% and a protein content of 3.37%. When analyzing the milk productivity of cows carrying different EAB alleles, the highest indicators were found in longevity cows having the following alleles in the EAB genotype: P1I/, B1I1T1A/2P/, Y2, Y2G/Y/G//1, Q B1G2KY2E/2F/2G/O/G//1 I1Y2E/2G/I/G//1, B2O3Y2A/2E/3G/P/Q/Y/ and B1I/Q/. The lifetime milk yield of cows with these markers was 28016 kg -33683 kg of milk, milk fat yield 1073.0 kg - 1339.1 kg, milk protein 694.7 kg - 1148.5 kg, with productive life duration of 9.2 - 11.3 years. Carriers of the EAB markers G2O2E/2I/, O2E/2G//1 and B1I/Q/ inherited from Jersey bulls used in the improvement of Brown Swiss cattle were distinguished by a higher fat and protein content in milk – 3.92% and 3.41%, respectively, they were used in a herd of 8.2 – 9.8 years. The leaders of productive longevity with a lifetime milk yield of over 40,000 kg of milk and a life duration of more than 13 years were cows whose genotypes contained the EAB-alleles G1O/, I/, I1, O/, P1I/, B1I1Q, B1G2KY2E/2F/2G/O/G//1 and B2O3Y2A/2E/3G/P/Q/Y/.

First Report of Papaya ring spot virus (PRSV) Infecting Jute (Corchorus olitorius) in India.

Jute is the most important bast fibre crop of the world, which is mainly cultivated in India, Nepal, Bangladesh, China, Indonesia and South American countries. The fibre is utilized for making apparels, ropes, bags, carpets etc (Biswas et al. 2014). This bio-fibre is gaining importance due to growing environmental consciousness worldwide. In June 2019, we noticed jute plants (less than 2%) showing virus like symptoms viz., downward curling, puckering, angular brownish to yellowish spots etc in a farmer's field at Amdanga Block, North 24 Paraganas, West Bengal, India. To identify the virus, five symptomatic leaves from five different plants were used for high throughput sequencing (HTS). We extracted total RNA from each leaf which was subjected to construction of cDNA libraries. Sequencing was done on Illumina Hiseq 4000 (CytoScan, Thermo Fisher). Approximately 46 million 105 nt paired end reads were generated. Raw reads were trimmed and filtered to perform de novo assembly as described previously by (Grabherr et al. 2013). The obtained contig was 10,326 bp nucleotides (nt) long and in BLASTn against GenBank showed highest identity with papaya ring spot virus (PRSV) with the contig covering 99.6% of the viral genome. The obtained contig shared 99.33% sequence similarity with PRSV strain P (Accession No. MT470188). The selected leaf samples were also tested by double-antibody sandwich (DAS)- enzyme linked immunosorbent assay (ELISA) for papaya ring spot virus (PRSV) along with some common viruses, viz., Potato leaf roll virus (PLRV), Watermelon mosaic virus, Cowpea mosaic virus and Cucumber mosaic virus with the help of commercial diagnostic kits (Agdia). However, only the test with PRSV gave positive reaction for the symptomatic samples. The major symptoms of PRSV on papaya are severe mosaic, chlorosis, reduced lamina with curling and puckering (Gonsalves et al. 2010). To confirm PRSV infection, five symptomatic leaf samples (used for HTS) were collected and whole RNA was extracted from the samples using RNeasy plant minikit (Qiagen, USA). Reverse transcriptase polymerase chain reaction (RT-PCR) was conducted by using isolated RNA. One pair of PRSV specific primer (PSRV1F: 5' TTAAATCTGATTCGTC 3' PRSV 1R: 5'GAAATTCACGCAAAGTCGA3') was developed by using primer BLAST software and was used in RT-PCR assays. Amplified fragments were cloned and sequenced and all the fragments shared 98% sequence identity with PRSV. One of the amplicons was deposited in NCBI (Accession No. MN615832). Crude sap was prepared by homogenizing PRSV-infected jute leaf tissues in 0.1 M sodium phosphate buffer and 2% carborundum dust was added as abrasive (Holkar et al. 2018). The sap was then gently rubbed on to the healthy papaya leaves for inoculation. Typical PRSV like symptoms appeared in inoculated leaves 10 days post inoculation which confirmed the presence of PRSV-P. PRSV was detected by RT-PCR as well as (DAS)-ELISA from all inoculated infected papaya leaf tissues, but could not be detected from uninoculated healthy papaya tissues. To the best of our knowledge, this is the first report of PRSV-P infecting jute in India.

The Genetic Landscape of Fiber Flax.

Genetic diversity in a breeding program is essential to overcome modern-day environmental challenges faced by humanity and produce robust, resilient crop cultivars with improved agronomic characteristics, as well as to trace crop domestication history. Flax (Linum usitatissimum), one of the first crops domesticated by mankind, has been traditionally cultivated for fiber as well as for medicinal purposes and as a nutritional product. The origins of fiber flax are hidden in the mists of time and can be hypothetically traced back to either the Indo-Afghan region or Fertile Crescent. To shed new light on fiber flax genetic diversity and breeding history, in this study, we presented a comprehensive analysis of the core collection of flax (306 accessions) of different morphotypes and geographic origins maintained by the Russian Federal Research Center for Bast Fiber Crops. We observed significant population differentiation between oilseed and fiber morphotypes, as well as mapped genomic regions affected by recent breeding efforts. We also sought to unravel the origins of kryazhs, Russian heritage landraces, and their genetic relatedness to modern fiber flax cultivars. For the first time, our results provide strong genetic evidence in favor of the hypothesis on kryazh’s mixed origin from both the Indo-Afghan diversity center and Fertile Crescent. Finally, we showed predominant contribution from Russian landraces and kryazhs into the ancestry of modern fiber flax varieties. Taken together, these findings may have practical implications on the development of new improved flax varieties with desirable traits that give farmers greater choice in crop management and meet the aspirations of breeders.

Genomic Regions Associated with Fusarium Wilt Resistance in Flax.

Modern flax cultivars are susceptible to many diseases; arguably, the most economically damaging of these is the Fusarium wilt fungal disease. Over the past decades international flax breeding initiatives resulted in the development of resistant cultivars. However, much remains to be learned about the mechanisms of resistance to Fusarium infection in flax. As a first step to uncover the genetic factors associated with resistance to Fusarium wilt disease, we performed a genome-wide association study (GWAS) using 297 accessions from the collection of the Federal Research Centre of the Bast Fiber Crops, Torzhok, Russia. These genotypes were infected with a highly pathogenic Fusarium oxysporum f.sp. lini MI39 strain; the wilt symptoms were documented in the course of three successive years. Six different single-locus models implemented in GAPIT3 R package were applied to a selected subset of 72,526 SNPs. A total of 15 QTNs (Quantitative Trait Nucleotides) were detected during at least two years of observation, while eight QTNs were found during all three years of the experiment. Of these, ten QTNs occupied a region of 640 Kb at the start of chromosome 1, while the remaining QTNs mapped to chromosomes 8, 11 and 13. All stable QTNs demonstrate a statistically significant allelic effect across 3 years of the experiment. Importantly, several QTNs spanned regions that harbored genes involved in the pathogen recognition and plant immunity response, including the KIP1-like protein (Lus10025717) and NBS-LRR protein (Lus10025852). Our results provide novel insights into the genetic architecture of flax resistance to Fusarium wilt and pinpoint potential candidate genes for further in-depth studies.