Torvum Sw Research Articles

Characterization of bacteria degrading 3-hydroxy palmitic acid methyl ester (3OH-PAME), a quorum sensing molecule of Ralstonia solanacearum.

Bacterial wilt pathogen Ralstonia solanacearum causes severe crop loss of eggplant, which is of economic importance in India. 3-hydroxy palmitic acid methyl ester (3OH-PAME) is the main quorum sensing molecule governing the expression of virulence factors in R.solanacearum. Ability of 164 bacterial isolates from the xylem of eggplant (Solanum melongena L.), chilli pepper (Capsicum annuum L.) and wild eggplant (Solanum torvum Sw.) to degrade 3OH-PAME was tested by disc diffusion assay. Enzymatic degradation of 3OH-PAME by five bacteria was confirmed by High-Performance Liquid Chromatography-Mass Spectrometry analysis. 3OH-PAME degrading bacteria were identified as Stenotrophomonas maltophilia, Pseudomonas aeruginosa and Rhodococcus corynebacterioides. 3OH-PAME degrading bacteria reduced the expression of virulence factors (exopolysaccharides and endoglucanase) of R.solanacearum in vitro and reduced wilt incidence in eggplant seedlings under greenhouse conditions. Isolates with quorum quenching activity successfully re-colonized eggplant seedlings. Quorum quenching bacteria produced antagonistic compounds, which may act synergistically with quorum quenching in reducing bacterial wilt in eggplant. This is the first report on endophytic bacteria of class Gammaproteobacteria and phylum Actinobacteria having 3OH-PAME degrading activity. This study demonstrates the potential use of endophytic bacteria as quorum quenching biocontrol agents for management of bacterial wilt in eggplant.

Zebrafish bioassay-guided microfractionation identifies anticonvulsant steroid glycosides from the Philippine medicinal plant Solanum torvum.

Medicinal plants used for the treatment of epilepsy are potentially a valuable source of novel antiepileptic small molecules. To identify anticonvulsant secondary metabolites, we performed an in vivo, zebrafish-based screen of medicinal plants used in Southeast Asia for the treatment of seizures. Solanum torvum Sw. (Solanaceae) was identified as having significant anticonvulsant activity in zebrafish larvae with seizures induced by the GABAA antagonist pentylenetetrazol (PTZ). This finding correlates well with the ethnomedical use of this plant in the Philippines, where a water decoction of S. torvum leaves is used to treat epileptic seizures. HPLC microfractionation of the bioactive crude extract, in combination with the in vivo zebrafish seizure assay, enabled the rapid localization of several bioactive compounds that were partially identified online by UHPLC-TOF-MS as steroid glycosides. Targeted isolation of the active constituents from the methanolic extract enabled the complete de novo structure identification of the six main bioactive compounds that were also present in the traditional preparation. To partially mimic the in vivo metabolism of these triterpene glycosides, their common aglycone was generated by acid hydrolysis. The isolated molecules exhibited significant anticonvulsant activity in zebrafish seizure assays. These results underscore the potential of zebrafish bioassay-guided microfractionation to rapidly identify novel bioactive small molecules of natural origin.

Diversity, biocontrol, and plant growth promoting abilities of xylem residing bacteria from solanaceous crops.

Eggplant (Solanum melongena L.) is one of the solanaceous crops of economic and cultural importance and is widely cultivated in the state of Goa, India. Eggplant cultivation is severely affected by bacterial wilt caused by Ralstonia solanacearum that colonizes the xylem tissue. In this study, 167 bacteria were isolated from the xylem of healthy eggplant, chilli, and Solanum torvum Sw. by vacuum infiltration and maceration. Amplified rDNA restriction analysis (ARDRA) grouped these xylem residing bacteria (XRB) into 38 haplotypes. Twenty-eight strains inhibited growth of R. solanacearum and produced volatile and diffusible antagonistic compounds and plant growth promoting substances in vitro. Antagonistic strains XB86, XB169, XB177, and XB200 recorded a biocontrol efficacy greater than 85% against BW and exhibited 12%–22 % increase in shoot length in eggplant in the greenhouse screening. 16S rRNA based identification revealed the presence of 23 different bacterial genera. XRB with high biocontrol and plant growth promoting activities were identified as strains of Staphylococcus sp., Bacillus sp., Streptomyces sp., Enterobacter sp., and Agrobacterium sp. This study is the first report on identity of bacteria from the xylem of solanaceous crops having traits useful in cultivation of eggplant.

Distribution of Major Sucking Pest, Helopeltis spp. (Hemiptera: Miridae) of Cashew in India

Surveys were conducted between 2010 and 2013 in west coast and east coast belts of India for major sucking pests, Helopeltis spp. in cashew. It reveals that three species viz., H. antonii Signoret, H. bradyi Waterhouse and H. theivora Waterhouse spread over different host plants. H. antonii was noticed as the predominant species and collected from 14 locations on five different host plants whereas; H.bradyi was collected from five locations on two host plants. The study also highlighted first record of H. antonii from Gujarat, Chhattisgarh and Odhisa cashew region. Similarly, H. bradyi was reported for the first time in high altitude Tura region, Meghalaya. H. theivora was predominant species on cashew in North East region. Incidence of Helopeltis spp. was very severe in most of the cashew growing tracts of Kerala, Karnataka, Goa and Maharashtra in the west coast region. Pachypeltis maesarum Kirkaldy was observed as a minor pest along with H. antonii on cashew and with H. theivora on Solanum torvum Sw.

Solanum torvum responses to the root-knot nematode Meloidogyne incognita.

BackgroundSolanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseases as bacterial, fungal wilts and root-knot nematodes. The little information on Solanum torvum (hereafter Torvum) resistance mechanisms, is mostly attributable to the lack of genomic tools (e.g. dedicated microarray) as well as to the paucity of database information limiting high-throughput expression studies in Torvum.ResultsAs a first step towards transcriptome profiling of Torvum inoculated with the nematode M. incognita, we built a Torvum 3’ transcript catalogue. One-quarter of a 454 full run resulted in 205,591 quality-filtered reads. De novo assembly yielded 24,922 contigs and 11,875 singletons. Similarity searches of the S. torvum transcript tags catalogue produced 12,344 annotations. A 30,0000 features custom combimatrix chip was then designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples resulting in 390 differentially expressed genes (DEG). We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena. An in-silico validation strategy was developed based on assessment of sequence similarity among Torvum probes and eggplant expressed sequences available in public repositories. GO term enrichment analyses with the 390 Torvum DEG revealed enhancement of several processes as chitin catabolism and sesquiterpenoids biosynthesis, while no GO term enrichment was found with eggplant DEG.The genes identified from S. torvum catalogue, bearing high similarity to known nematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism.ConclusionsBy combining 454 pyrosequencing and microarray technology we were able to conduct a cost-effective global transcriptome profiling in a non-model species. In addition, the development of an in silico validation strategy allowed to further extend the use of the custom chip to a related species and to assess by comparison the expression of selected genes without major concerns of artifacts. The expression profiling of S. torvum responses to nematode infection points to sesquiterpenoids and chitinases as major effectors of nematode resistance. The availability of the long sequence tags in S. torvum catalogue will allow precise identification of active nematocide/nematostatic compounds and associated enzymes posing the basis for exploitation of these resistance mechanisms in other species.

Effect of Different Light on Pollen Germination, Tube Growth, Fruit Set and Fruit size in Alkaloid Yielding Plant Solanum Torvum Sw.

The present study showed the improvement of S. torvum plant through the effect of different light on pollen germination, pollen tube growth, fruit set, fruit size and fresh weight of ripened fruits. The pollen grains of S. torvum were germinated on a basal medium and study the effect of blue, green, white, yellow and red light under in–vitro condition. Percent of pollen germination and tube growth were lesser in the dark condition than the white light but maximum by the red light in 4 and 5 hrs incubation. Based on pollen germination and tube growth variability in-vitro from different light. Hundred long-styled flowers (before anthesis) were chosen randomly for each colour and after hand pollination obtained the per cent of fruit set, size and weight of ripened fruit was lesser in the dark as compared to other lights and aforementioned these values were maximum under the red light. Thus, the present work emphasised that the red light should be used for the improvement of fruit size in S. torvum.

Phytochemistry and pharmacological studies on Solanum torvum Swartz

Article history: Received on: 19/02/2013 Revised on: 03/03/2013 Accepted on: 03/04/2013 Available online: 27/04/2013 The botany, traditional medicinal uses, phytochemistry, and pharmacology of S. torvum Sw. belonging to family Solanaceae have been reviewed by evaluating information on the Internet (using Google Scholar, CABAbstracts, Blackwell synergy, Elsevier, Cambridge University Press, JSTOR, Nature Publishing and Science online) and in libraries. Traditional medicinal uses of S. torvum were recorded in the Ayurveda and Chinese pharmacopeia. The present review study covered chemical constituents and pharmacological properties of S. torvum as well as its morphology. This has included therapeutic effects of the whole plant and its extracts, fractions and isolated compounds. Antimicrobial, anti-ulcerogenic, antiviral, anti-platelet aggregation, antioxidant, analgesic, anti-inflammatory, systolic blood-pressure modification, and cytotoxic activities have all been described. Previous research studies carried out using different in-vitro and in-vivo bioassay techniques supported the claims of the therapeutic utility of the species.

Leaf epidermal characters of Brazilian species of Solanum section Torva as taxonomic evidence

To evaluate their taxonomic significance, the yet unknown epidermal characters of the leaves of 10 species of Solanum section Torva Nees (Solanaceae) from Brazil were determined using light and scanning electron microscopy. Our results indicated that the leaf epidermis showed epidermal cells of straight to wavy outlines. The curved pattern of anticlinal cell walls was predominant on the adaxial surface, and the wave pattern was predominant on the abaxial surface. Leaves are amphistomatic in six species ( Solanum acutilobum Dunal, Solanum bonariense L., Solanum guaraniticum A. St.-Hil., Solanum metrobotryon Dunal, Solanum scuticum M. Nee, and Solanum torvum Sw.) and hypostomatic in four species ( Solanum adspersum Witasek, Solanum paniculatum L., Solanum subumbellatum Vell., and Solanum variabile Mart.). Four different types of stomata (anisocytic, anomocytic, paracytic, and diacytic) were recognized, with the anisocytic type predominant on adaxial and abaxial surfaces. The combination of some micro-morphological characters such as density, distribution and type of stellate trichomes, the anticlinal walls of epidermal cells, and also the type and distribution of stomata proved to be the most useful and distinctive characters for the separation of species. This set of characters also may help as additional support in quality control of species having medicinal importance.

Eggplant relatives as sources of variation for developing new rootstocks: Effects of grafting on eggplant yield and fruit apparent quality and composition

We propose the utilization of eggplant ( Solanum melongena L.) interspecific hybrids derived from crosses with closely related species as an approach for developing new improved rootstocks for eggplant. Here we investigate rootstock effects on fruit yield, apparent quality and proximate and mineral composition of S. melongena ‘Black Beauty’ (BB) scions grafted on interspecific hybrid rootstocks developed from crosses of S. melongena with Solanum incanum L. (SI × SM) and Solanum aethiopicum L. (SM × SA). The results are compared with non-grafted (BB control) and self-grafted (BB/BB) controls and with S. melongena ‘Black Beauty’ scions grafted onto Solanum torvum Sw. (STO) and Solanum macrocarpon L. (SMA) rootstocks. All treatments were grown in a soil naturally infested with root-knot nematodes (mostly Meloidogyne incognita (Kofoid and White) Chitwood). SI × SM and SM × SA interspecific hybrids had high germination (≥90%) and total graft success (100%). Contrary to what occurred with all other treatments, no plants from scions grafted onto these hybrid rootstocks died during the experiment. In particular, the SI × SM hybrid rootstock conferred the highest vigour to the scion, which resulted in the highest values for fruit earliness and early and total yield. Little difference was observed among treatments for apparent fruit quality traits, except for a greater fruit calyx length and prickliness of fruit grafted onto SMA rootstocks. A similar result was obtained for fruit composition where phenolics content was higher in fruit from plants grafted onto SMA rootstocks. Grafting eggplant onto interspecific eggplant hybrids, especially on the SI × SM hybrid, has proved advantageous for eggplant production, as the high vigour and good compatibility of the rootstock with scion results in improved early and total yield without negative effects on apparent fruit quality or composition. Interspecific hybrids represent an alternative to the commonly used STO rootstock, which is a wild species with irregular germination.

Differential expression analysis by cDNA-AFLP of Solanum torvum upon Verticillium dahliae infection

Differentially expressed genes in eggplant (Solanum torvum SW) during root infection with Verticillium dahliae were identified using cDNA-amplified restriction fragment polymorphism (cDNA-AFLP) approach. A total of 140 differential transcript-derived fragments (TDFs) were isolated, in which 79 TDFs were up-regulated, and 34 TDFs were down-regulated after inoculation. BLAST analysis showed that 51% of these TDFs belonged to function-known genes. Further analysis on six TDFs (TDF11, TDF14, TDF16, TDF25, TDF26, and TDF39), which represented different expression patterns, was done. TDF11, encoding cytochrome c oxidase, appeared in 24 h after inoculation; TDF14, encoding retrotransposon protein, disappeared in 6 h after treatment; TDF16, encoding bZIP transcription factor, began to express only in 72 h after inoculation; TDF25, encoding senescence-associated protein, was present between 6 and 24 h; TDF26, encoding cytochrome P450 monooxygenase, and TDF39, encoding metallophosphoesterase, were up-regulated during the entire period after inoculation. Results obtained demonstrated that the defense of S. torvum against V. dahliae is a complex multigene process, which studying is helpful for better understanding verticillium wilt resistance of S. torvum.

Ethnopharmacological use of herbal remedies for the treatment of malaria in the Dangme West District of Ghana

Aim of study Malaria is one of the most important diseases in the world. Because of the devastating nature of the disease there is an urgent need to develop new drugs or vaccines for the treatment, prevention and management of the disease. The objective of the present study was to collect and document information on herbal remedies traditionally used for the treatment of malaria in the Dangme West District of Ghana. Methods Data was collected from 67 indigenous households in ten communities in the district using a validated questionnaire. Results In total, 30 species of plants belonging to 28 genera in 20 families were reported to be used in the preparation of the herbal remedies. Mature leaves were the most (55%) common plant part used and 73.3% of the herbal remedies involved a single plant. Most of the herbal remedies were prepared by boiling and administered orally. The majority (47%) of the species of plants used were collected from their compounds or home gardens. Conclusions Knowledge about malaria and treatment practices exists in the study area. Herbal remedies were commonly used by people for the treatment of malaria because they were cost-effective. They are also more accessible. Many of the species of plants used have been documented for the treatment of malaria as well as investigated for their phytochemical and antimalarial and/or antiplasmodial activity confirming the results of previous studies as well as rationalization of their traditional use. Five species of plants used in the study area, namely, Bambusa vulgaris Schrad. ex J.C. Wendl. (Poaceae), Deinbollia pinnata Schum. &Thonn. (Sapindaceae), Elaeis guineensis Jacq. (Arecaceae), Greenwayodendron sp. (Annonaceae) and Solanum torvum Sw (Solanaceae), are documented for the first time for their use in the treatment of malaria. “The result of this study provides the basis for further pharmacological studies on the herbal remedies used”.

Solasodine accumulation in regenerated plants of Solanum torvum Sw

A nodal segment culture was developed in order to assess Solanum torvum Sw. regeneration and solasodine levels. The influence of auxins (indoleacetic acid, 1-Naphthaleneacetic acid) and benzyl adenine on S. torvum growth in micropropagation was investigated. A nodal segment culture was initiated with seeds germinated in MS basal medium added of GA3 and grown in different concentrations of IAA, IAA + BAP and NAA + BAP. Sixty-day-old plants from the in vitro culture were collected, frozen and lyophilized; then, the methyl orange method was used to quantify solasodine for the spectrophotometric assay. The best results regarding plant regeneration and solasodine accumulation were obtained by using the MS basal medium without addition of plant growth regulators; however, there was great production of calluses presenting friable bases. Based on these results, cell cultures can be initiated from such calluses with application of other auxins and cytokinins to enhance solasodine production, besides different elicitors, light intensities and sucrose concentrations.

Grafted eggplant yield, quality and growth in infested soil with Verticillium dahliae and Meloidogyne incognita

The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw.) on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L.) cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis) is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala). Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.

Flower and fruit volatiles assist host-plant location in the Tomato fruit flyNeoceratitis cyanescens

Mature females of the tomato fruit fly Neoceratitis cyanescens can detect host fruit at a short distance using only visual stimuli, but little is known about the role of airborne volatile cues in the host searching strategy. A series of experiments is conducted in a laboratory wind tunnel, in which the behavioural responses of individual flies to volatiles from Solanaceae host plants (including tomato Lycopersicum esculentum Mill., bug weed Solanum mauritianum Scop. and Turkey berry Solanum torvum Sw.) are observed, according to some environmental (air speed) and physiological (age and mating status of females, time of day) factors. Mature females respond primarily to specific olfactory cues from blends of flowers or host fruit, preferentially unripe fruit for bug weed, as opposed to ripe fruit for Turkey berry or tomato. Males are also highly attracted by the odour of unripe fruit of bug weed. Wind plays a key role, as shown by the proportion of flies that reach the upwind section of the tunnel in the presence of both fruit odour and air flow (66.7%) and in the absence of either fruit odour (13.3%) or wind (36.7%). In response to fruit volatiles carried by wind, flies embark in a 'plume tracking' or 'aim and shoot' flight, consistent with odour-conditioned anemotaxis. Females respond to host fruit odour regardless of their age, egg load or mating status, and also more consistently in the afternoon, which is their preferential time of day for egg-laying. Searching behaviour and response to host volatiles in N. cyanescens are discussed in the light of host-finding and an adaptive strategy.

Gene expression analysis in cadmium-stressed roots of a low cadmium-accumulating solanaceous plant, Solanum torvum

Solanum torvum Sw. cv. Torubamubiga (TB) is a low cadmium (Cd)-accumulating plant. To elucidate the molecular mechanisms of the Cd acclimation process in TB roots, transcriptional regulation was analysed in response to mild Cd treatment: 0.1 μM CdCl2 in hydroponic solution. A unigene set consisting of 6296 unigene sequences was constructed from 18 816 TB cDNAs. The distribution of functional categories was similar to tomato, while 330 unigenes were suggested to be TB specific. For expression profiling, the SuperSAGE method was adapted for use with Illumina sequencing technology. Expression tag libraries were constructed from Cd-treated (for 3 h, 1 d, and 3 d) and untreated roots, and 34 269 species of independent tags were collected. Moreover, 6237 tags were ascribed to the TB or eggplant (aubergine) unigene sequences. Time-course changes were examined, and 2049 up- and 2022 down-regulated tags were identified. Although no tags annotated to metal transporter genes were significantly regulated, a tag annotated to AtFRD3, a xylem-loading citrate transporter, was down-regulated. In addition to induction of heavy metal chaperone proteins, antioxidative and sulphur-assimilating enzymes were induced, confirming that oxidative stress developed even using a mild Cd concentration. Rapid repression of dehydration-related transcription factors and aquaporin isoforms suggests that dehydration stress is a potential constituent of Cd-induced biochemical impediments. These transcriptional changes were also confirmed by real-time reverse transcription-PCR. Further additions of TB unigene sequences and functional analysis of the regulated tags will reveal the molecular basis of the Cd acclimation process, including the low Cd-accumulating characteristics of TB.

Palinologia de espécies de Solanum L. (Solanaceae A. Juss.) ocorrentes nas restingas do Estado do Rio de Janeiro, Brasil

Foram estudados 21 táxons de Solanum L., com o objetivo de caracterizá-los palinologicamente e, assim, contribuir para a elaboração de um catálogo polínico da flora das restingas do Estado do Rio de Janeiro. Os táxons examinados foram Solanum affine Sendtn., Solanum americanum Mill. var. americanum,Solanum argenteum Dunal ex Poir., Solanum aturense Dunal, Solanum caavurana Vell., Solanum capsicoides All., Solanum carautae Carv., Solanum cordifolium Dunal, Solanum curvispinum Dunal, Solanum echidnaeforme Dunal, Solanum gardneri Sendtn.,Solanum indigoferum A. St.-Hil., Solanum insidiosum Mart., Solanum mauritianum Scop., Solanum paludosum Moric., Solanum paniculatum L., Solanum paratyense Vell., Solanum pseudoquina A.St.-Hil., Solanum sisymbriifolium Lam., Solanum torvum Sw., Solanum velleum Sw. Os grãos de pólen foram acetolisados, mensurados, descritos e fotomicrografados. A análise sob microscopia eletrônica de varredura foi utilizada, em grãos de pólen não acetolisados, para confirmar as descrições feitas sob microscopia de luz e, em alguns casos para confirmar as descrições de abertura e ornamentação. Constatou-se que os grãos de pólen são pequenos ou médios, isopolares, subprolatos a oblato-esferoidais, 3-colporados, sexina granulada, rugulado-granulada ou escabrada. Pela análise dos resultados obtidos pôde-se concluir que os táxons analisados apresentam certa heterogeneidade polínica, quanto à forma, aos atributos das aberturas e à ornamentação da sexina, podendo-se usar estes caracteres na taxonomia do gênero.

Natural establishment of a parasitoid complex on Bactrocera latifrons (Diptera: Tephritidae) in Hawaii

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is the most recent of four tephritid fruit fly species accidentally introduced into Hawaii. Although parasitoids have been released against other tephritid fruit fly species and have shown partial success in Hawaii, no parasitoids were released until 2004 to suppress populations of B. latifrons. The present study was conducted to document the parasitoid complex that has naturally established against B. latifrons in Hawaii and to assess whether there is a need for improving the biological control of this species. Based on ripe turkeyberry (Solanum torvum Sw) fruit collections over three consecutive years B. latifrons was the dominant tephritid fruit fly infestating turkeyberry at all four sites surveyed, across three major islands in Hawaii. The overall percentage parasitism of B. latifrons ranged from a low of 0.8% (Hana, Maui) to a high of 8.8% (Kahaluu, Oahu). Five primary parasitoid species were recovered from individually held B. latifrons puparia: Fopius arisanus (Sonan), Psyttalia incisi (Silvestri), Diachasmimorpha longicaudata (Ashmead), D. tryoni (Cameron), and Tetrastichus giffardianus Silvestri. F. arisanus was the predominant parasitoid at three of the four sites. Low levels of parasitism suggest that there is a need to improve biological control of B. latifrons, to minimize chances of this species causing economic impacts on crop production in Hawaii. We discuss the possibility of improving biological control of B. latifrons through augmentative releases of F. arisanus or introduction and release of specific and efficient new parasitoid species.

Grafting and calcium cyanamide as alternatives to methyl bromide for greenhouse eggplant production

Eggplant ( Solanum melongena L.) seedlings (cv. Tsakoniki) were cultivated in soil artificially infested with V. dahliae Kleb. and then sterilized by either methyl bromide (MB) or calcium cyanamide. Grafted seedlings on the wild species Solanum torvum Sw. and the control seedlings (auto-rooted) were cultivated in soil sterilized by MB and then artificially infested with V. dahliae. The plants grafted on S. torvum and the ones grown in soil treated with calcium cyanamide (2001) exhibited significantly lower leaf symptom index (average value LSI = 1.55 and LSI = 1.00) and disease index (average value DI = 2.05 and DI = 1.20), respectively, as compared to the controls (average value LSI = 3.80 and DI = 5.50). Grafted plants on S. torvum and plants grown in soil treated with calcium cyanamide (2001) were more vigorous, as measured by plant height, stem diameter and root biomass than the controls. This resulted in an increased (over years) early (487.8% and 416.2%, 2001) and late production (277.0% and 241.3%, 2001) and mean fruit weight (over years) in early (93.7% and 49.6%, 2001) and late production (38.3% and 22.8%, 2001) as compared to the controls. In conclusion, grafting of eggplant and soil sterilized by calcium cyanamide had positive effects on growth, production and Verticillium wilt control.

PRELIMINARY STUDY OF ANTIMICROBIAL ACTIVITIES ON MEDICINAL HERBS OF THAI FOOD INGREDIENTS

PRELIMINARY STUDY OF ANTIMICROBIAL ACTIVITIES ON MEDICINAL HERBS OF THAI FOOD INGREDIENTS

Solanum torvum, as a useful source of resistance against bacterial and fungal diseases for improvement of eggplant ( S. melongena L.)

Accessions of Solanum torvum SW, a wild relative of eggplant, were collected in Java Island, Indonesia, and assessed for morphology, fertility, levels of resistance against both Ralstonia solanacearum and Fusarium oxysporum f. sp. melongenae, as well as the genetic diversity by using RAPD and I-SSR markers. When grown to maturity in the field in Bogor, Indonesia, plants were very vigorous and showed a high polymorphism in all characters examined among the accessions, except for the stem diameter and the number of branches. The relatively high heterogeneity in morphology and fertility could not be related to the geographical origin of the accessions surveyed, and was not corroborated by genetic analysis. By using RAPD markers, 8.4% polymorphism were detected in two genotypes (BML and BG1) among the 11 accessions analysed, whereas screening with I-SSR markers has resulted in 3.3% polymorphism in three accessions, BG1, CN1 and CN2. This therefore gives a global 4.7% polymorphism, individualising only four accessions among the 11 tested. Twenty nine accessions of S. torvum and eggplant, cv Pusa Purple Long used as positive control, were evaluated for resistance to R. solanacearum (race 1 biovar 3, strain T926) in the greenhouse in Bogor. All inoculated plants of eggplant died within 2 weeks. Bacterial wilt symptoms occurred on lower leaves of S. torvum plants tested without however causing any plant death. The presence of bacteria, serologically detected in roots of symptomless plants, suggested S. torvum to be tolerant to R. solanacearum. A sample of 10 accessions was shown to be highly resistant to an Italian isolate of F. oxysporum f. sp. Melongena, while the cultivated eggplant, line Tina used as positive control, died within 2 weeks after inoculation. The low levels of genetic diversity of Javanese accessions of S. torvum and their relatively homogeneous response in tolerance and resistance to bacterial and fungal wilts are discussed, respectively.