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Construction industries demand a material with high strength to endure severe environmental conditions like high temperature and humid and hence, it is noteworthy to assess the thermal and water transport properties of the material. In this investigation, the natural fibers based composites were fabricated using Indian almond and kenaf fibers by hand layup method. Entirely, two natural fiber composites viz. epoxy/Indian almond & epoxy/kenaf and two hybrid composites viz. kenaf/India almond/kenaf (K/I/K) & Indian almond/kenaf/Indian almond (I/K/I) were prepared. Thermogravimetric analysis (TGA) was carried out to analyze the thermal properties and water absorption study was carried out to analyze the transport properties. TGA study showed that the epoxy/kenaf composite exhibited a maximum onset temperature of 340.49°C owing to good bonding strength and the K/I/K composite displayed a maximum decomposition temperature of 380.21 ° with a minimum mass loss of 1.29 mg/min. Further, the epoxy/Indian almond composite showed a better flame retardancy property due to more char formation. Water absorption study resulted that the epoxy/Indian almond composite absorbed more water (35% at 50°C) compared to other composites due to spongy like structure and the presence of more voids on the surface of the fiber. Further, the epoxy/kenaf composite displayed more resistance to water penetration with maximum activation energy of diffusion of 2.63 kJ/mole. Transport properties such as diffusion coefficient, sorption coefficient and permeability coefficient were varied in line with temperature. The epoxy/kenaf composite showed least diffusion coefficient of 2.48 × 10−5 cm2/s, sorption coefficient of 1.05, and permeability coefficient of 2.61 × 10−5 cm2/s at 30°C among all other composites due to good bonding strength. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinus) is an annual fiber crop grown mainly in India and China. This crop is becoming a new bio‐based energy source because of its fast growth rate, excellent CO2 absorption ability, and large productivity per unit area. In this study, we evaluated 10 different cultivars of kenaf for their potential as biomass for cellulosic ethanol production. First, kenaf samples were hydrolyzed using dilute sulfuric acid, which is the most simple and cost‐effective pretreatment method. Next, simultaneous saccharification and fermentation (SSF) of the hydrolysates were performed by wild‐type and engineered xylose‐fermenting yeast strains. The results of compositional analysis of the biomass, the hydrolysates, and the fermented products suggested that ethanol yield and productivity were significantly affected by a type of kenaf cultivars, which was not predictable based on the biomass compositions. Also, the ethanol production was maximized when the xylose fraction was utilized by engineered yeast under the control of pH to avoid acetate inhibition. Considering the sugar compositions and their fermentability, kenaf can be a promising energy‐dedicated crop for cellulosic ethanol production. [ABSTRACT FROM AUTHOR]

Kenaf ( Hibiscus cannabinus ) and roselle ( H. sabdariffa ) commonly known as mesta or ambadi in India, primarily considered as fibre crop in addition to their diversified use as vegetables, food supplements, paper pulp, construction material, animal feed, pharmacological agent, biofuel etc. Both kenaf and roselle seeds contain a variety of bioactive phytochemicals like polyphenols and phenolic acids, phytosterols, amino acids, fatty acids, phospholipids etc. that possess great nutritional, phyto-pharmaceutical and therapeutic values. Mesta seed contain 22–24% oil and is considered to have high nutritional value and health promoting properties due to the presence of relatively high amount of monounsaturated and polyunsaturated fatty acids (MUFAs and PUFAs). Kenaf and roselle seeds are also good source of dietary fibers and proteins that have great promise as a feed resource for livestock and value added nutritional foods like defatted seed meal, protein concentrates from defatted seed, seed cake etc. Our institute has developed high yielding and stress resistant varieties of both crops with breeding efforts centered on developing high yielding types with better fibre quality. Recently, identification of high yielding mesta lines with more oil content changed focus toward development of low cyclopropenoid fatty acids (CPFA), epoxy fatty acids, palmitic (saturated) acid content along with increased omega PUFAs content varieties. The present review focuses on the detailed profile of valuable phytochemicals, nutrients, and health promoting attributes as well as phyto-technological progress, nutraceutical functions, medicinal and biological properties of kenaf and roselle seed oil, so as to explore their potential uses as ingredients of functional food and natural pharmaceuticals. [ABSTRACT FROM AUTHOR]

Infection of stolbur phytoplasma was detected in kenaf (Hibiscus cannabinus) plants at CRIJAF research farm, Barrackpore, India. The infected plants formed profuse short branches at the top with bushy and bunchy top appearance. PCR with universal 16S rDNA phytoplasma primers P1/P7 yielded amplicons of 1.5 kb from all symptomatic leaf samples. Nested PCR with 16S-rDNA-specific nested primer pair R16F2n/R2 generated an amplicon of 1241 bp confirming the presence of a phytoplasma. The nested PCR products were sequenced and BALSTn analysis revealed 100% identity with 16S rRNA gene of phytoplasma. Phylogenetic analysis showed kenaf phytoplasma having 99% identity with both “Bois noir” stolbur phytoplasma 16SrXII group (Accession no: JQ181540). The RFLP data also supported the phylogenetic analysis. Multi-locus sequence characterisation assay was conducted by using different locus-specific primers viz. tuf, rpsC-rplV, rplF-rplR, map-SecY and uvrB-degV. The infected phytoplasma samples amplified only SecY gene and generated 1224 bp product which was deposited at NCBI (accession no: KC508636). [ABSTRACT FROM AUTHOR]

Mesta (Hibiscus sabdariffa) is an important fibre crop in the north coastal zone of Andhra Pradesh which accounts for 59% of India's total production of mesta. The area under this crop has reduced dramatically in recent years and in order to understand the contribution of weather to this decline, long-term experimental data (14 years) on mesta cv. AMV-4 and regional crop yields were analysed. Crop yields decreased in seasons when rainfall exceeded 900 mm and maximum temperature remained below 32.0°C during 10–16 weeks after sowing (WAS), which coincided with the active vegetative stage. The average yields of the region were high when seasonal rainfall ranged between 600 and 725 mm. Increased fibre yields were observed when increasing seasonal rainfall coincided with maximum temperatures exceeding 33.5°C. Fibre yields from a long-term experiment showed strong positive correlations with maximum temperature during 6–16 WAS (r = 0.79) and with mean diurnal temperature range (8.6–10.7°C) during 11–19 WAS (r = 0.66). Step-wise regression showed that maximum variability in fibre yield was explained by maximum temperature which could be used to develop models to predict yield at least one month in advance with acceptable accuracy. This prediction could then be used as an input for crop planning and market intelligence. [ABSTRACT FROM AUTHOR]

Abstract: Yellow vein mosaic disease of mesta (Hibiscus spp.) poses a serious threat to the cultivation of this crop in India. The disease was found to be associated with two different whitefly-transmitted monopartite begomoviruses, Mesta yellow vein mosaic virus and Mesta yellow vein mosaic Bahraich virus, together with two betasatellite species, Cotton leaf curl Multan betasatellite and Ludwigia leaf distortion betasatellite. These begomovirus complexes were detected in different combinations throughout the mesta growing regions of India. All the eight cultivars tested were highly susceptible to the disease. The effect of the disease in terms of loss in fibre yield was greatest (around 70%) in plants that were inoculated at an early stage of growth. A regression approach was adopted to consider the relationship of whitefly vector populations with weather conditions and disease spread which explained that different conducive weather factors facilitated the build up of whitefly populations and contributed to the spread of the disease. [Copyright &y& Elsevier]

Yellow vein mosaic disease of mesta in northern India was found to be associated with a distinct begomovirus species. Except the AC1 gene, this begomovirus isolate shares low sequence identity with the Mesta yellow vein mosaic virus reported to be associated with a similar disease of mesta from eastern India. [ABSTRACT FROM AUTHOR]

Ten medicinal plants, namely Commiphora wightii, Hibiscus cannabinus, Anethum gravelons, Emblica officinalis, Ficus religiosa, Ficus racemosa, Ficus benghalensis, Ficus tisela, Mentha arvensis and Mimusops elengi, were screened for potential antibacterial activity against medically important bacterial strains, namely Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Bacillus cereus, Alcaligenes faecalis and Salmonella typhimurium. The antibacterial activity was determined in aqueous and ethanol extracts using both agar disc diffusion and agar well diffusion methods. The ethanol extracts were more potent than aqueous extracts of all the plants studied. Pseudomonas aeruginosa and Salmonella typhimurium were the most resistant strains while the most susceptible bacterial strains were Bacillus cereus and Proteus mirabilis. Emblica officinalis showed strong activity against all the tested bacterial strains. Hence, this plant can be used to discover bioactive natural products that may serve as leads in the development of new pharmaceuticals that address unmet therapeutic needs. [ABSTRACT FROM AUTHOR]

Occurrence of yellow vein mosaic disease of mesta ( Hibiscus cannabinus L. and H. sabdariffa L.) was found to be endemic in parts of India. For rapid and sensitive diagnosis of the Begomovirus associated with this disease, a radiolabelled diagnostic method has been developed. Southern hybridization and nucleic acid spot hybridization using radiolabelled probes to the coat protein (CP) gene of DNA A and DNA β of the virus were able to detect the virus both in plants and in viruliferous whiteflies. These probes detected the presence of the same virus in experimentally infected Vigna plants showing only leaf crumpling symptoms. These probes were also able to detect infection in other crops, ornamentals and weed plants showing characteristic symptoms of whitefly-transmitted geminiviruses. Polymerase chain reaction amplification through primers specific to the CP gene, full-length DNA A and full-length DNA β molecules using DNA isolated from all infected plants and viruliferous whiteflies detected presence of same virus in them. [ABSTRACT FROM AUTHOR]

Yellow vein mosaic disease of mesta is whitefly-transmitted and found in endemic form in different parts of India, causing great economic losses. Full-length DNA-A of a begomovirus infecting mesta was cloned and sequenced. The genome was homologous to the DNA-A of monopartite begomoviruses originating from the Old World, with six conserved open reading frames. The complete nucleotide sequence of the DNA-A molecule of the present isolate was 2728 nucleotides in length, having the highest sequence identity (83.5%) with an Indian begomovirus causing cotton leaf curl disease. It thus belongs to a novel geminivirus species, and the name Mesta yellow vein mosaic virus is proposed. [ABSTRACT FROM AUTHOR]