Cyphomandra betacea is one of the underutilized fruits which can be found in tropical and subtropical countries. This study was conducted to determine the antioxidant activity and phytochemical contents in different parts (i.e., flesh and peel) of the fruits. Antioxidants were analyzed using DPPH and ABTS free radical scavenging assays as well as FRAP assay. Anticholinesterase activity was determined using enzymatic assay using acetyl cholinesterase enzyme. For 80% methanol extract, the peel of the fruit displayed higher antioxidant activity in both FRAP and ABTS free radical scavenging assays while the flesh displayed higher antioxidant activity in the DPPH assay. Total phenolic and total flavonoid content were higher in the peel with the values of 4.89 ± 0.04 mg gallic acid equivalent (GAE)/g and 3.36 ± 0.01 mg rutin equivalent (RU)/g, respectively. Total anthocyanin and carotenoid content were higher in the flesh of the fruit with the values of 4.15 ± 0.04 mg/100 g and 25.13 ± 0.35 mg/100 g. The anticholinesterase was also higher in the peel of C. betacea. The same trends of phytochemicals, antioxidant, and anticholinesterase were also observed in the distilled water extracts. These findings suggested that C. betacea has a potential as natural antioxidant-rich nutraceutical products.
Waste-to-energy conversion presents a pivotal strategy for mitigating the energy crisis and curbing environmental pollution. Pyrolysis is a widely embraced thermochemical approach for transforming waste into valuable energy resources. This study delves into the co-pyrolysis of terrestrial biomass (potato peel) and marine biomass (Sargassum angastifolium) to optimize the quantity and quality of the resultant bio-oil and biochar. Initially, thermogravimetric analysis was conducted at varying heating rates (5, 20, and 50 °C/min) to elucidate the thermal degradation behavior of individual samples. Subsequently, comprehensive analyses employing FTIR, XRD, XRF, BET, FE-SEM, and GC-MS were employed to assess the composition and morphology of pyrolysis products. Results demonstrated an augmented bio-oil yield in mixed samples, with the highest yield of 27.1 wt% attained in a composition comprising 75% potato peel and 25% Sargassum angastifolium. As confirmed by GC-MS analysis, mixed samples exhibited reduced acidity, particularly evident in the bio-oil produced from a 75% Sargassum angastifolium blend, which exhibited approximately half the original acidity. FTIR analysis revealed key functional groups on the biochar surface, including O-H, CO, and C-O moieties. XRD and XRF analyses indicated the presence of alkali and alkaline earth metals in the biochar, while BET analysis showed a surface area ranging from 0.64 to 1.60 m2/g. The favorable characteristics of the products highlight the efficacy and cost-effectiveness of co-pyrolyzing terrestrial and marine biomass for the generation of biofuels and value-added commodities.
This study determined the heavy metals (HMs) accumulation in different vegetables in different seasons and attributed a serious health hazard to human adults due to the consumption of such vegetables in Jhansi. The total amounts of zinc (Zn), lead (Pb), nickel (Ni), manganese (Mn), copper (Cu), cobalt (Co), and cadmium (Cd) were analysed in 28 composite samples of soil and vegetables (Fenugreek, spinach, eggplant, and chilli) collected from seven agricultural fields. The transfer factor (TF) of HMs from soil to analysed vegetables was calculated, and significant non-carcinogenic health risks due to exposure to analysed heavy metals via consumption of these vegetables were computed. The statistical analysis involving Principal Component Analysis (PCA) and Pearson's correlation matrix suggested that anthropogenic activities were a major source of HMs in the study areas. The target hazard quotient of Cd, Mn, and Pb for fenugreek (2.156, 2.143, and 2.228, respectively) and spinach (3.697, 3.509, 5.539, respectively) exceeded the unity, indicating the high possibilities of non-carcinogenic health risks if regularly consumed by human beings. This study strongly suggests the continuous monitoring of soil, irrigation water, and vegetables to prohibit excessive accumulation in the food chain.
The present study was designed to evaluate the potential of microbial adaptation and its affinity to biodegradation as well as bioconversion of soluble/insoluble (organic) substances of domestic wastewater treatment plant (DWTP) sludge (activated domestic sludge) under natural/non-sterilized conditions. The two filamentous fungi, Penicillium corylophilum (WWZP1003) and Aspergillus niger (SCahmA103) were used to achieve the objectives. It was observed that P. corylophilum (WWZP1003) was the better strain compared to A. niger (SCahmA103) for the bioconversion of domestic activated sludge through adaptation. The visual observation in plate culture showed that about 95-98% of cultured microbes (P. corylophilum and A. niger) dominated in treated sludge after 2 days of treatment. In this study, it was also found that the P. corylophilum was capable of removing 94.40% of COD and 98.95% of turbidity of filtrate with minimum dose of inoculum of 10% v/v in DWTP sludge (1% w/w). The pH level was lower (acidic condition) in the fungal treatment and maximum reduction of COD and turbidity was observed (at lower pH). The results for specific resistance to filtration (SRF) showed that the fungi played a great role in enhancing the dewaterability and filterability. In particular, the strain Penicillium had a more significant capability (than A. niger) of reducing 93.20% of SRF compared to the uninoculated sample. Effective results were observed by using fungal inoculum after 2 days of treatment. The developed LSB process is a new biotechnological approach for sludge management strategy.
This paper describes the design and development of harvesting system for the gantry system to harvest eggplants. For this purpose, the harvesting robot was successfully designed and fabricated for the gantry system to harvest eggplants. The operation of the harvester was controlled by Programmable Logic Controller (PLC). Basically, the limit switches, DC motor, and relay are connected to the PLC. Meanwhile, a PLC ladder diagram was designed and developed to control the operation of the eggplant harvester. A visual basic programme was developed to interface the harvester with a greenhouse gantry control system. A videogrammetry method was employed to calculate the distance between the stems of eggplants and the cutter of robot end effector. The end effector used electric as its power source and it was controlled via Programmable Logic Controller (PLC). Visual Basic Programme was developed to interface the harvester with the gantry control system. The accuracy of the videogrammetry was tested to be 67.2% for X-axis, 88.2% for Y-axis and 84.7% for Z-axis. Meanwhile, the speed of the end effector for harvester is 2.4 km/h and it could lift up to 55 cm. In order to determine detachment force of eggplant, 16 samples of mature eggplants were tested in a greenhouse, and as a result, more than 22.76 N force was needed to detach a mature eggplant inside the gantry system.
In the context of food security, examining the genomics of domestication will help identify genes underlying adaptive and economically important phenotypes, for example, larger fruit, improved taste, and loss of agronomically inferior phenotypes. Examination of genome-scale single nucleotide polymorphisms demonstrates the relationships between wild ancestors of eggplant (Solanum melongena L.), confirming that Solanum insanum L. is the wild progenitor. This species is split roughly into an Eastern (Malaysian, Thai, and Vietnamese) and Western (Indian, Madagascan, and Sri Lankan) group, with domesticates derived from the former. Additional "wild" accessions from India appear to be feral escapes, derived multiple times from domesticated varieties through admixture. Accessions with small egg-shaped fruit are generally found intermixed with East Asian Solanum insanum confirming they are primitive relative to the large-fruited domesticates. Comparative transcriptomics was used to track the loci under selection. Sequence analysis revealed a genetic bottleneck reducing variation by almost 50% in the primitive accessions relative to the wild species and a further 10% in the landraces. We also show evidence for selection on genes with a role in response to wounding and apoptosis. Genes showing a significant difference in expression between wild and primitive or between primitive and landrace genepools were mostly (>75%) downregulated in the derived populations and enriched for gene ontologies related to defense, flowering, signaling, and response to biotic and abiotic stimuli. This work reveals genomic changes involved in crop domestication and improvement, and the population genetics work explains why defining the eggplant domestication trajectory has been so challenging.
The main objective of the present study was to investigate the effects of the frying media and storage time on the fatty acid composition (FAC) and iodine value (IV) of deep-fat fried potato chips. The frying experiment was conducted at 180ºC for five consecutive days. Six frying media were considered as the main treatments: refined, bleached, deodorized (RBD) palm olein (A), canola oil (C), RBD palm olein/sesame oil (AB, 1:1 w/w), RBD palm olein/canola oil (AC, 1:1, w/w), sesame oil/canola oil (BC, 1:1, w/w), and RBD palm olein/sesame oil/canola oil (ABC, 1:1:1, w/w/w). The initial degrees of unsaturation of the consumed oils, A, C, AB, AC, BC, and ABC, were 58.6, 94.0, 68.0, 72.2, 87.7, and 75.8 (g/100 g), respectively. The fatty acid analysis showed that there was a decrease in both the linolenic acid (C18:3) and linoleic acid (C18:2) contents, whereas the palmitic acid (C16:0) increased with a prolonged frying time. The chemical analysis showed that there was a significant (p < 0.05) difference in terms of the IV for each frying oil during the five consecutive days of frying (day 0 to 5). Oil C had the least stability in terms of deep-fat frying due to a high level of unsaturated fatty acids. Conversely, oil AC had the best stability due to the smallest reduction of the C18:2/C16:0 ratio and the IV.
This study was conducted to identify the causal organism of bark dieback disease of highbush blueberry (Vaccinium corymbosum L.) observed in Korea. Blueberry, a woody plant that is native to North America, belongs to the family Ericaceae and genus Vaccinium. Of the 400 species of blueberry in the world, most are distributed in the tropics of Malaysia and Southeast Asia. Highbush blueberry is abundantly grown in Canada and the United States and has become a popular commercial crop in Korea for products such as jam, wine, and sauce. Bark dieback disease of blueberry was found in Sunchang (<5% incidence), Jeollabuk-do, Korea in July 2009. Typical symptoms of the disease were blight and dieback on the stems with lesions extending along entire branches. Morphological examination revealed that the perithecia were of the globose type with a nipple, 155 to 490 (374.6) μm, and brown on the dead bark. Asci were bitunicate and clavate or cylindrical with dimensions of 63 to 125 × 16 to 20 μm and containing eight ascospores. Ascospores were of the long ovoid type with dimensions of 13.2 to 23.7 (17.98) × 25.4 to 41.1 (33.21) μm. From extracted genomic DNA, the internal transcribed spacer (ITS)-5.8S ribosomal DNA region was amplified with universal primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'). A BLAST search of GenBank with the ITS sequence revealed that the Sunchang isolate (GenBank Accession No. HQ384217) had 99 to 100% sequence identity with the following Botryosphaeria dothidea accessions: FJ517657, AJ938005, FJ478129, FJ171723, and AJ938004. Phylogenetic analysis with the Sunchang isolate, B. dothidea strains, and related species revealed that the B. dothidea isolate and strains comprised a monophyletic group distinguished from other Botryosphaeria spp. including B. ribis, B. parva, B. protearum, B. lutea, B. australis, B. rhodina, B. obtuse, and B. stevensii (2). On the basis of morphological and molecular results, the isolate was identified as B. dothidea (Moug.) Ces. & De Not. A culture of B. dothidea isolate was grown on potato dextrose agar (PDA) for 10 days. A 5-mm plug was inoculated into stem wounds created with a No. 2 cork borer in 20 2-year-old disease-free blueberry plants grown in a greenhouse. Six plants inoculated with only PDA plugs served as noninoculated controls. The wounds were covered with Parafilm. After 3 months, the Parafilm was removed and black lesions were observed at the fungal inoculation sites, while no lesion was observed on the control plants. To complete Koch's postulates, the fungus was reisolated from the lesions and confirmed to be B. Dothidea (1). There is an urgent need to determine the spread of this disease in Korea, estimate the losses, and develop methods for reducing damage through biological and eco-friendly cultural control methods. References: (1) D. Jurc et al. Plant Pathol. 55:299, 2006. (2) B. Slippers et al. Mycologia 96:83, 2004.
Glaciozyma antarctica PI12 is a psychrophilic yeast isolated from Antarctica. It has an optimal growth in yeast peptone dextrose (YPD) and yeast mould (YM) broth media but not in potato dextrose (PD) broth medium. Early phase G. antarctica PI12 cells had elongated-shape and became oval-shaped as they aged. G. antarctica PI12 exhibited bipolar budding and formed a chain of cells during the lag and early exponential phases. The number of chains decreased as the yeast aged. It appeared mainly as a single cell at the stationary phase, and a small number of them still produced buds. Some cells at the stationary phase entered the quiescence state (G0) as a longterm survival strategy. The G. antarctica PI12 cell size decreased when they entered the stationary phase. G. antarctica PI12 was found to produce hydrolytic enzymes, chitinase, cellulase, mannanase, and xylanase. A higher glucose concentration of 2% in the PD agar medium inhibited the activities of chitinase but not the cellulase, mananase and xylanase.
The key aroma constituents in the volatile fractions isolated FROM two differently processed fry breads by solvent-assisted flavor evaporation were characterized by an aroma extract dilution analysis (AEDA). Twenty-two compounds were identified with flavor dilution (FD) factor ranges of 2-516. Among them, 13 compounds (FD ≥ 16) were quantified by stable isotope dilution assays and analyzed by odor activity values (OAVs). Of these, 11 compounds had OAVs ≥ 1, and the highest concentrations were determined for δ-decalactone and 2,3-butanedione. Two recombination models of the fry breads showed similarity to the corresponding fry breads. Omission tests confirmed that aroma-active constituents, such as δ-decalactone (oily/peach), 2-acetyl-1-pyrroline (roasty/popcorn-like), 3-methylbutanal (malty), methional (baked potato-like), 2,3-butanedione (buttery), phenyl acetaldehyde (flowery), (E,E)-2,4-decadienal (deep-fried), butanoic acid, and 3-methylbutanoic acid, were the key aroma constituents of fry bread. In addition, 3-methoxy-4-vinylphenol (smoky) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were also identified as important aroma constituents of fry bread.
Indian spinach (Basella rubra L.) is a red stem species of Basella that is cultivated worldwide as an ornamental and the aerial parts are also consumed as a vegetable. In May of 2011, symptoms of damping-off were observed on approximately 10% of the plants at the stem base around the soil line of seedlings in a greenhouse in Homestead, FL. Lesions were initially water soaked, grayish to dark brown, irregular in shape, and sunken in appearance on large plants, causing the infected seedlings to collapse and eventually die. Symptomatic stem tissue was surface sterilized with 0.6% sodium hypochlorite, rinsed in sterile distilled water, air dried, and plated on potato dextrose agar (PDA). Plates were incubated at 25°C in darkness for 3 to 5 days. A fungus was isolated in all six isolations from symptomatic tissues on PDA. Fungal colonies on PDA were light gray to brown with abundant growth of mycelia, and the hyphae tended to branch at right angles when examined under a microscope. A septum was always present in the branch of hyphae near the originating point and a slight constriction at the branch was observed. Neither conidia nor conidiophores were found from the cultures on PDA. The characteristics of hyphae, especially the right angle branching of mycelia, indicate close similarity to those of Rhizoctonia solani (2,3). The internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced (GenBank Accession No. JN545836). Subsequent database searches by the BLASTN program indicated that the resulting sequence had a 100% identity over 472 bp with the corresponding gene sequence of R. solani anastomosis group (AG) 4 (GenBank Accession No. JF701752.1), a fungal pathogen reported to cause damping-off on many crops. Pathogenicity was confirmed through inoculation of healthy India spinach plants with the hyphae of isolates. Four 4-week-old plants were inoculated with the isolates by placing a 5-mm PDA plug of mycelia at the stem base and covering with a thin layer of the soil. Another four plants treated with sterile PDA served as a control. After inoculation, the plants were covered with plastic bags for 24 h and maintained in a greenhouse with ambient conditions. Four days after inoculation, water-soaked, brown lesions, identical to the symptoms described above, were observed on the stem base of all inoculated plants, whereas no symptoms developed on the control plants. The fungus was isolated from affected stem samples, and the identity was confirmed by microscopic appearance of the hyphae and sequencing the ITS1/ITS4 intergenic spacer region, fulfilling Koch's postulates. This pathogenicity test was conducted twice. R. solani has been reported to cause damping-off of B. rubra in Ghana (1) and Malaysia (4). To our knowledge, this is the first report of damping-off caused by R. solani AG-4 on Indian spinach in Florida and the United States. With the increased interest in producing Asian vegetables for food and ornamental purposes, the occurrence of damping-off on Indian spinach needs to be taken into account when designing programs for disease management in Florida. References: (1) H. A. Dade. XXIX. Bull. Misc. Inform. 6:205, 1940. (2) J. R. Parmeter et al. Phytopathology 57:218, 1967. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St Paul, MN, 1991. (4) T. H. Williams and P. S. W. Liu. Phytopathol. Pap. 19:1, 1976.
Association analysis was conducted in a core collection of 94 genotypes of Solanum pimpinellifolium to identify variations linked to salt tolerance traits (physiological and yield traits under salt stress) in four candidate genes viz., DREB1A, VP1.1, NHX1, and TIP. The candidate gene analysis covered a concatenated length of 4594 bp per individual and identified five SNP/Indels in DREB1A and VP1.1 genes explaining 17.0% to 25.8% phenotypic variation for various salt tolerance traits. Out of these five alleles, one at 297 bp in DREB1A had in-frame deletion of 6 bp (CTGCAT) or 12 bp (CTGCATCTGCAT), resulting in two alleles, viz., SpDREB1A_297_6 and SpDREB1A_297_12. These alleles individually or as haplotypes accounted for maximum phenotypic variance of about 25% for various salt tolerance traits. Design of markers for selection of the favorable alleles/haplotypes will hasten marker-assisted introgression of salt tolerance from S. pimpinellifolium into cultivated tomato.
Endophytic fungi are those living inside the host plant without causing any apparent negative effect on the host plant. Two
isolates endophytic fungi from leaves and two isolates from root at Universiti Teknologi MARA (UiTM) Reserve Forest,
Negeri Sembilan were successfully isolated and identified by morphology and molecular characteristic. Samples were
surface sterilized and sub-cultured to obtain a pure culture. Characteristics of the isolates such as colony appearance,
mycelial texture, conidia/spores and pigmentation were studied to explore their morphology. Isolates were also subjected to
a PCR-based genotyping test. There were noticeable differences in morphological characteristics among the four isolates.
Microscopic analysis showed four isolates consist of septa and conidia/spores. The pigmentation result showed that
colony in A1leaf samples demonstrated an orange color on potato dextrose agar (PDA) media, colony in A1root demonstrate
a black texture in PDA media while hairy colonies in the others two isolates showed a white color on PDA media. Based on
molecular analyses the fungal genera showed 99-100% similarity with the related fungi recorded in the GenBank. Both
morphology and molecular sequencing of internal transcribed spacer (ITS) regions of endophytic fungi showed that three
isolates (A1root, C2leaf, and C3root) were grouped in Basidiomycota while one isolate (A1leaf) belonged to Ascomycota. The
endophyte funguses were identified as Daldinia sp. (A1leaf), Polyporales sp. (A1root,) Lentinus sp. (C2leaf,) and Rigidoporus
sp. (C3root). Overall, the new discoveries of isolated endophyte fungal have dyeing potential of fungal pigments which
offer a viable alternative to natural vegetable and harmful synthetic dyes.
Marine fungus Fusarium proliferatum derived from marine sponge collected along Pulau Tinggi, Malaysia was cultivated on Potato Dextrose Broth and incubated for 7 days at 30oC. The liquid cultures were then extracted using ethyl acetate. The crude extract was investigated for its anti-microbial activity and was passed through Sephadex column and the fractions were collected. Reverse phase HPLC was used to monitor the component of crude extract. HPLC guided purification of crude extract resulted in the isolation of linoleic acid, 4-hydroxy phenethyl alcohol, 2,5-furandimethanol and adenosine. Their structures were elucidated by spectroscopic methods.
A preliminary study was conducted to determine the level of oxidative DNA damage, fruits and vegetables intake among 50 breast cancer patients (cases) as compared to 50 healthy women (controls) with no known medical history of breast cancer in Klang Valley. Both groups were matched for age and ethnicity. Data on socio-demographic, health status and medical history, fruits and vegetables intake, and supplements intake were obtained through an interviewbased questionnaire. Anthropometry measurements included weight, height, and waist and hip circumference were also carried out on subjects. A total of 3mL fasting venous blood was drawn to assess lymphocytes oxidative DNA damage using Alkaline Comet Assay. Results indicated that the mean intake of fruits and vegetables was lower in cases (4.09 ± 1.17 servings/d) than controls (4.77 ± 0.90 servings/d)(p < 0.05) The intake of fruits and vegetables from family groups of solanaceae, myrtaceae, caricaceae, apiaceae, brinjal, rutaceae, broccoli, orange, carrot, watermelon were 0.5 - 1 servings/week significantly higher among controls as compared to cases (p < 0.05 for all parameters). However, the intake of fruits from rosaceae family and apple was higher among controls than cases (p < 0.05). The estimated intake of ß-carotene, carotenoids, vitamin A, vitamin C (p < 0.001), a-carotene and lycopene (p < 0.05) from fruits and vegetables were higher among controls than cases. Mean DNA damage level of cases (4.55 ± 1.78 % DNA in tail, %TD; 0.35 ± 0.21 tail moment, TM) were 3.5 and 3.9 times higher than the value of controls (1.3 ± 0.70% TD; 0.09 ± 0.09 TM) (p < 0.001) and the damage increased with higher values of waist hip ratio (% TD, r = 0.396, p < 0.05; TM, r = 0.349, p < 0.05) and waist circumference (% TD, r = 0.334, p < 0.05; TM, r = 0.360, p < 0.05). There was an inverse relationship between oxidative DNA damage with intake of total fruits and vegetables, cauliflowers and water convolvulus and also consumption from rutaceae and solanaceae families. Similar trend was noted for estimated intake of vitamin A, carotenoids, vitamin C, ß-carotene and lycopene. In conclusion, the intake of fruits and vegetables of five servings/d and the consumption of specific families and types of fruits and vegetables might protect against oxidative DNA damage and further reduce breast cancer risk.
Social bacteria use chemical communication to coordinate and synchronize gene expression via the quorum-sensing (QS) regulatory pathway. In Pectobacterium, a causative agent of the blackleg and soft-rot diseases on potato plants and tubers, expression of the virulence factors is collectively controlled by the QS-signals N-acylhomoserine lactones (NAHLs). Several soil bacteria, such as the actinobacterium Rhodococcus erythropolis, are able to degrade NAHLs, hence quench the chemical communication and virulence of Pectobacterium. Here, next-generation sequencing was used to investigate structural and functional genomics of the NAHL-degrading R. erythropolis strain R138. The R. erythropolis R138 genome (6.7 Mbp) contained a single circular chromosome, one linear (250 kbp) and one circular (84 kbp) plasmid. Growth of R. erythropolis and P. atrosepticum was not altered in mixed-cultures as compared with monocultures on potato tuber slices. HiSeq-transcriptomics revealed that no R. erythropolis genes were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the avirulent P. atrosepticum mutant expI, which is defective for QS-signal synthesis. By contrast 50 genes (<1% of the R. erythropolis genome) were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the NAHL-producing virulent P. atrosepticum. Among them, quantitative real-time reverse-transcriptase-PCR confirmed that the expression of some alkyl-sulfatase genes decreased in the presence of a virulent P. atrosepticum, as well as deprivation of organic sulfur such as methionine, which is a key precursor in the synthesis of NAHL by P. atrosepticum.
Dickeya solani species are emerging bacterial pathogens of Solanum tuberosum Here, we announce the complete genome sequences of two strains, Dickeya solani D s0432-1 and PPO 9019. Strain PPO 9019 represents the first described member of the genus Dickeya with an extrachromosomal genetic element.
Pectobacterium wasabiae was originally isolated from Japanese horseradish (Eutrema wasabi), but recently some Pectobacterium isolates collected from potato plants and tubers displaying blackleg and soft rot symptoms were also assigned to P. wasabiae. Here, combining genomic and phenotypical data, we re-evaluated their taxonomic position. PacBio and Illumina technologies were used to complete the genome sequences of P. wasabiae CFBP 3304T and RNS 08-42-1A. Multi-locus sequence analysis showed that the P. wasabiae strains RNS 08-42-1A, SCC3193, CFIA1002 and WPP163, which were collected from potato plant environment, constituted a separate clade from the original Japanese horseradish P. wasabiae. The taxonomic position of these strains was also supported by calculation of the in-silico DNA-DNA hybridization, genome average nucleotide indentity, alignment fraction and average nucleotide indentity values. In addition, they were phenotypically distinguished from P. wasabiae strains by producing acids from (+)-raffinose, α-d(+)-α-lactose, d(+)-galactose and (+)-melibiose but not from methyl α-d-glycopyranoside, (+)-maltose or malonic acid. The name Pectobacterium parmentieri sp. nov. is proposed for this taxon; the type strain is RNS 08-42-1AT (=CFBP 8475T=LMG 29774T).
Dickeya solani is an emerging pathogen that causes soft rot and blackleg diseases in several crops including Solanum tuberosum, but little is known about its genomic diversity and evolution.
In 2011, a severe gray leaf spot was observed on eggplant (Solanum melongena) in major eggplant growing areas in Malaysia, including the Pahang, Johor, and Selangor states. Disease incidence was >70% in severely infected areas of about 150 ha of eggplant greenhouses and fields examined. Symptoms initially appeared as small (1 to 5 mm diameter), brownish-black specks with concentric circles on the lower leaves. The specks then coalesced and developed into greyish-brown, necrotic lesions, which also appeared on the upper leaves. Eventually, the leaves senesced and were shed. Tissue cut from the edges of leaf spots were surface-sterilized in 1% NaOCl for 2 min, rinsed in sterilized water, dried, and incubated on potato dextrose agar (PDA). Fungal colonies were greyish green to light brown, and produced a yellow pigment. Single, muriform, brown, oblong conidia formed at the terminal end of each conidiophore, were each 21.6 to 45.6 μm long and 11.5 to 21.6 μm wide, and contained 2 to 7 transverse and 1 to 4 longitudinal septa. The conidiophores were tan to light brown and ≤220 μm long. Based on these morphological criteria, 25 isolates of the fungus were identified as Stemphylium solani (1). To produce conidia in culture, 7-day-old single-conidial cultures were established on potato carrot agar (PCA) and V8 juice agar media under an 8-h/16-h light/dark photoperiod at 25°C (4). Further confirmation of the identification was obtained by molecular characterization in which fungal DNA was extracted and the internal transcribed spacer (ITS) region of ribosomal DNA amplified using primers ITS5 and ITS4 (2), followed by direct sequencing. A BLAST search in the NCBI database revealed that the sequence was 99% identical with published ITS sequences for two isolates of S. solani (Accession Nos. AF203451 and HQ840713). The amplified ITS region was deposited in GenBank (JQ736023). Pathogenicity testing of a representative isolate was performed on detached, 45-day-old eggplant leaves of the cv. 125066-X under laboratory conditions. Four fully expanded leaves (one wounded and two non-wounded leaflets/leaf) were placed on moist filter paper in petri dishes, and each leaflet inoculated with a 20-μl drop of a conidial suspension containing 1 × 105 conidia/ml in sterilized, distilled water (3). The leaves were wounded by applying pressure to leaf blades with the serrated edge of forceps. Four control leaves were inoculated similarly with sterilized, distilled water. Inoculated leaves were incubated in humid chambers at 25°C with 95% RH and a 12-h photoperiod. After 7 days, symptoms similar to those observed in the original fields developed on both wounded and non-wounded inoculated leaves, but not on control leaves, and S. solani was reisolated consistently from the symptoms using the same method as the original isolations. Control leaves remained asymptomatic and the fungus was not isolated from these leaves. The pathogenicity testing was repeated with similar results. To our knowledge, this is the first report of S. solani on eggplant in Malaysia. References: (1) B. S. Kim et al. Plant Pathol. J. 20:85, 2004. (2) Y. R. Mehta et al. Curr. Microbiol. 44:323, 2002. (3) B. M. Pryor and T. J. Michailides. Phytopathology 92:406, 2002. (4) E. G. Simmons. CBS Biodiv. Series 6:775, 2007.