Cytotoxic Effect on Human Cancer Cells and Antioxidant Activity of Extracts of <Emphasis Type="Italic">Codonopsis lanceolata</Emphasis> Root using Different Solvent Fractions

This study was conducted to investigate cytotoxic effect, phenolic content, DPPH, ABTS radical scavenging rate and nitrite scavenging rate from different solvent fractions of Codonopsis lanceolate root. At all extracts concentration, the cytotoxic effect on different fractions against human cancer cells was higher in n-hexane and butyl alcohol fractions than in the other fractions. The IC₅₀ value on HeLa cell showed the lowest by 62.70 μg.mL^-1 on n-hexane fraction, and exhibited the values of butyl alcohol fraction 341.36 μg.mL^-1, methylene chloride 598.33 μg.mL^-1, ethyl acetate fraction 860.44 μg.mL^-1, DW fraction 2896.82 μg.mL^-1. Total polyphenol content on different solvent fractions varied from 102.43 to 153.52 mg.g^-1, and that of ethyl acetate fraction showed the highest amount. The DPPH and ABTS radical scavenging activity showed that the increase was proportional to the concentration, and the scavenging activity also showed the highest in ethyl acetate fraction. The nitrite scavenging activity of each fraction at pH 1.2 was in the order of EA > BA > MC > n-H > DW, and the lower the acidity, the higher nitrite scavenging activity, and there was no distinct detection of nitrite scavenging effects of the pH range 6.0. The results of this study suggested that the extract of Codonopsis lanceolate root may assist in the potential biological activities, and it was found that the activity was different depending on the organic solvent fraction and the water fraction.     

Antioxidant capacity and phenolic content of <Emphasis Type="Italic">Rumex dentatus</Emphasis> L. Grown in Egypt

Rumex dentatus L. (Family: Polygonaceae) is a weedy plant widely distributed in many countries including Egypt. It has been used in the Mediterranean diet as a leafy vegetable and its leaves and roots exhibited various biological activities. In our study, total phenolics, antioxidant capacities assayed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching methods and reducing power were evaluated in different extracts/fractions of leaves and roots of R. dentatus grown in Egypt. In addition, their phenolic compositions were determined by GC-MS and HPLC. The results showed that total phenolic content in the ethyl acetate fractions of leaves and roots were high and measured at 169.5 and 257.4 mg gallic acid equivalent per g extract, respectively. The ethyl acetate fractions of leaves and roots exhibited strong DPPH activity and the DPPH IC₅₀ values were 0.021 and 0.012 mg mL⁻¹ of leaves and roots, respectively. Furthermore, the ethyl acetate fractions of leaves and roots showed high reducing power and antioxidant activity assayed by β-carotene bleaching method. GC-MS and HPLC analyses indicated that these fractions contained a variety of phenolic compounds including p-hydroxybenzoic acid, syringic acid, vanillin, benzoic acid, ferulic acid, and cinnamic acid. Our study verified that the ethyl acetate fractions of leaves and roots of R. dentatus have strong antioxidant activities which are correlated with its high levels of phenolic compounds and therefore, they could be utilized as a natural source of antioxidant in food industry.     

Resynthesizing <Emphasis Type="Italic">Brassica napus</Emphasis> from interspecific hybridization between <Emphasis Type="Italic">Brassica rapa</Emphasis> and <Emphasis Type="Italic">B. oleracea</Emphasis> through ovary culture

Using three varieties of Brassica rapa, cv. Hauarad (accession 708), cv. Maoshan-3 (714) and cv. Youbai (715), as the maternal plants and one variety of B. oleracea cv. Jingfeng-1 (6012) as the paternal plant, crosses were made to produce interspecific hybrids through ovary culture techniques. A better response of seed formation was observed when ovaries were cultured in vitro at 9–12 days after pollination on the basal MS and B5 media supplemented with 6-benzylaminopurine (BA) and naphthylacetic acid (NAA). The best response was observed for cross 714×6012 with the rate of seeds per ovary reaching 43.0%. Seeds for cross 715×6012 showed the best germination response (66.7%) on the regeneration medium (MS+1.0 mg l^–1 BA+0.05 mg l^–1 NAA). In all three cross combinations, good response in terms of root number and length of plants was observed on the root induction medium (MS+1.0 mg l^–1 BA+0.1 mg l^–1 NAA). A better response was observed for the regenerated plants cultured for 14 days than for 7 days. The ovary-derived plants with well-developed root system were hardened for 8 days and their survival rate reached over 80%. Cytological studies showed that the chromosome number of all plants tested was 19 (the sum of both parents), indicating that these regenerated plants were all true hybrids of B. rapa (n = 10) × B. oleracea (n = 9). The regenerated plants were doubled with colchicine treatment, and the best response in the crosses 708×6012, 714×6012 and 715×6012 was observed when treated with 170 mg l^–1 colchicine for up to 30 h and their doubling frequency reached 52, 56 and 62%, respectively.     

An efficient <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation protocol for black pepper (<Emphasis Type="Italic">Piper nigrum</Emphasis> L.) using embryogenic mass as explant

A protocol was developed for an efficient Agrobactertium-mediated transformation of black pepper plants through somatic embryogenesis. Embryogenic mass derived from primary somatic embryos that were obtained from the micropylar region of mature germinating seeds of black pepper was found to be the ideal target tissue for transformation. Genetic fidelity test of embryogenic mass-derived plantlets by RAPD using 23 random primers revealed no genetic variation among the progenies and the parent plant. Among the antibiotics used for selection of transformants, cefotaxime at 100 μg mL⁻¹ was found to be optimum to control Agrobacterium besides its ability to promote somatic embryo proliferation. In the case of kanamycin, a step-wise increase in concentration from 25 to 50 and then to 100 μg mL⁻¹ were found to be optimum. Embryogenic mass co-cultivated with Agrobacterium carrying the β-glucuronidase (GUS) reporter gene were cultured on plant growth regulator-free Schenk and Hildebrandt (SH) medium and transformants were selected in selection medium containing cefotaxime and step-wise increase in kanamycin concentration. The transient GUS gene expression was determined histochemically. Transformants that survived in the selection medium were hardened in the greenhouse. An average of nine hardened putative plantlets was obtained per gram of embryogenic mass. The presence of transgene in these plantlets was assayed by PCR, dot blot, and Southern blot hybridization. Results presented demonstrated for the first time an efficient transformation and regeneration of black pepper without the use of growth regulators. This simple efficient procedure would allow transformation of black pepper with genes of desirable characters.     

Expression of <Emphasis Type="Italic">Bruguiera gymnorhiza</Emphasis><Emphasis Type="Italic">BgARP1</Emphasis> enhances salt tolerance in transgenic <Emphasis Type="Italic">Arabidopsis</Emphasis> plants

We have previously reported that expression of salt-responsive genes, including Bruguiera gymnorhiza ankyrin repeat protein 1 (BgARP1), enhances salt tolerance in both Agrobacterium tumefaciens and Arabidopsis. In this report, we further characterized BgARP1-expressing Arabidopsis to elucidate the role of BgARP1 in salt tolerance. BgARP1-expressing plants exhibited more vigorous growth than wild-type plants on MS plates containing 125–175 mM NaCl. Real-time PCR analysis showed enhanced induction of osmotin34 in the 2-week-old transformants under 125 mM NaCl. It was also showed that induction of typical salt-responsive genes, including RD29A, RD29B, and RD22, was blunted and delayed in the 4-week-old transformants during 24 h after 200 mM NaCl treatment. Ion content analysis showed that transgenic plants contained more K⁺, Ca²⁺, and NO₃ ⁻, and less NH₄ ⁺, than wild-type plants grown in 200 mM NaCl. Our results suggest that BgARP1-expressing plants may reduce salt stress by up-regulating osmotin34 gene expression and maintaining K⁺ homeostasis and regulating Ca²⁺ content. These results indicate that BgARP1 is functional on a heterogeneous background.     

Induction of Shikonin production in hairy root cultures of <Emphasis Type="Italic">Arnebia hispidissima</Emphasis> via <Emphasis Type="Italic">Agrobacterium rhizogenes</Emphasis>-mediated genetic transformation

Data presented herein provides a rapid and efficient method for Agrobacterium rhizogenes-mediated genetic transformation of Arnebia hispidissima for hairy root cultures as well as for enhancing Shikonin production. Etiolated explants viz. shoot tip, nodal, leaf and internodal segments were co-cultivated with Agrobacterium rhizogenes for induction of hairy root. Among the various explants employed, leaf explant showed maximum 70.7% response followed by shoot tip 48.3%, nodal segment 38.7% and internodal segment 9.3%. Integration of Ri plasmid rolB gene in the transformed hairy root cultures was confirmed by PCR analysis using forward (FrolB) and reverse (RrolB) primers of rolB gene resulting in the amplification of 0 ∼ 0.8 kb fragments. Medium compositions have been optimized for in vitro induction of Shikonin in hairy root cultures of Arnebia hispidissima. Hairy roots on hormonefree MS medium showed red spots in the older part of the tissues which turned white after a second subculture. Whereas hairy roots cultured on RC medium showed faster growth and produced large amount of Shikonin. The Shikonin content in transformed hairy root culture was estimated by recording absorbance at 620 nm and quantified against authentic sample of Shikonin. Shikonin content was estimated to be 0.85 mg g⁻¹ fresh weight of tissue at the end of the 50 days of culture. The results presented herein will help to design strategies for bridging the gap between ever increasing demand and supply of raw products necessary for obtaining Shikonin for cosmetic, dyeing, food, medicinal, and pharmaceutical industries.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) with a fungal phytase gene improves phosphorus acquisition

A phytase gene (phyA), isolated from Aspergillus ficuum (AF537344), was introduced into cotton (Gossypium hirsutum L.) by Agrobacterium-mediated transformation to increase the phosphorus (P) acquisition efficiency of cotton. Southern and Northern blot analyses showed that the phyA was successfully incorporated into the cotton genome and expressed in transgenic lines. After growing for 45 days with phytate (Po) as the only P source, the shoot and root dry weights of the transgenic plants all increased by nearly 2.0-fold relative to those of wild-type plants, but were similar to those of transgenic plants supplied with inorganic phosphorus. The phytase activities of root extracts prepared from transgenic plants were 2.4- to 3.6-fold higher than those from wild-type plants, and the extracellular phytase activities of transgenic plants were also 4.2- to 6.3-fold higher. Furthermore, the expressed phytase was secreted into the rhizospheres as demonstrated by enzyme activity staining. The transgenic plants accumulated much higher contents of total P (up to 2.1-fold after 30 days of growth) than the wild-type plants when supplied with Po. These findings clearly showed that cotton plant transformed with a fungal phytase gene was able to secret the enzyme from the root, which markedly improved the plant’s ability to utilize P from phytate. This may serve as a promising step toward the development of new cotton cultivars with improved phosphorus acquisition.     

Measurement of the field response of <Emphasis Type="Italic">Musa</Emphasis> genotypes to <Emphasis Type="Italic">Radopholus Similis</Emphasis> and <Emphasis Type="Italic">Helicotylenchus Multicinctus</Emphasis> and the implications for nematode resistance breeding

Crop growth and damage parameters (plant growth and yield, root damage and nematode population densities), believed to be associated with resistance of Musa genotypes to nematodes under field conditions, were evaluated in a field trial of 24 Musa genotypes inoculated at planting with a combination of Radopholus similis and Helicotylenchus multicinctus with the objective to identify parameters with strong association with nematode resistance and high heritability. Correlation and path analysis of the association between plant growth, yield, root damage and nematode population densities showed a strong negative association between percentage dead roots, percentage root necrosis, R. similis and H. multicinctus population densities and yield. The strongest negative association was observed between percentage dead roots and yield. Broad-sense genotype heritability estimates demonstrated that heritability estimates for percentage dead roots, number of large lesions and nematode population density were most affected by inoculation with nematodes. These results indicate therefore that effective selection for nematode resistance under field conditions could be obtained by using an index, that includes percentage dead roots, the number of large lesions, and nematode population density.     

Phytochemical distribution and antioxidant activities of Korean adzuki bean (<Emphasis Type="Italic">Vigna angularis</Emphasis>) landraces

Total polyphenol content (TPC), total phenolic acid content (TPA), and total flavonoid content (TFC) in 209 Korean adzuki bean landraces were determined by colorimetric methods. Antioxidant effects were evaluated with the DPPH, ABTS, ferric reducing antioxidant power (FRAP), reducing power (RP), and SOD assays. TPC, TPA, and TFC in the 209 Korean adzuki bean landraces ranged from 1.1 to 11.7 mg gallic acid equivalents/g, 0.37 to 5.03 mg caffeic acid equivalents/g, and 0.17 to 0.91 mg quercetin equivalents/g, respectively. Antioxidant activities as assessed by the DPPH, ABTS, FRAP, PR, and SOD assays showed wide variation, ranging from 12.2 to 86.3 (IC₅₀), 0.85 to 5.25 mg ascorbic acid equivalents (ASC)/g, 0.41 to 5.44 mg ASC/g, 0.54 to 1.83 mg ASC/g, and 60.4 to 142.8 (IC₅₀), respectively. Using the relative antioxidant capacity index (RACI), we found that the IT189394 had the highest antioxidant activity. In clustering analysis, 209 Korean adzuki bean landraces were classified into three clusters. Among them, cluster I contained 22 landraces with higher antioxidant activities, TPC, TFC, and TPA and smaller seed sizes than the other clusters. We anticipate that these results will provide useful information for the development of adzuki bean-based functional foods.     

Resistance screening of <Emphasis Type="Italic">Coffea</Emphasis> spp. accessions for <Emphasis Type="Italic">Pratylenchus coffeae</Emphasis> and <Emphasis Type="Italic">Radopholus arabocoffeae</Emphasis> in Vietnam

Coffee varieties with resistance for the plant-parasitic nematodes Pratylenchus coffeae and Radopholus arabocoffeae are limited in Vietnam. A selection of imported varieties and high yield varieties of Arabica coffee in Vietnam were evaluated for resistance to both plant-parasitic nematode species in Northern Vietnam. The same experiments were carried out with hybrid arabica coffee, three selected clones of Coffea canephora and one clone of Coffea excelsa in the Western Highland of Vietnam. The screened coffee accessions from Ethiopia (KH1, KH13, KH20, KH21, KH29, and KH31) were susceptible and good host for P. coffeae. Also accessions 90P4 (Portugal) and Oro azteca (Mexico) had a reproduction factor Rf > 1. Pluma Hidalgo (Mexico), 90/6 (Vietnam), 90P3 (Portugal), 90P2 (Vietnam), Variedad (Mexico), 90T (Portugal), and Garnica (Mexico) were poor hosts (Rf < 1) but not tolerant to P. coffeae, expressed by a reduction of root weight compared to untreated control plants. Most of the coffee accessions tested in Northern Vietnam were intolerant to R. arabocoffeae, except 90T which showed no reduction of root weight, even at high initial nematode densities (4,000/pot). Good hosts for R. arabocoffeae were Variedad, KH1, KH21, KH29, KH20, KH31, and KH13 with Rf > 1. Pluma Hidalgo, 90/6, 90P3, 90P2, 90T, Oro azteca, and Garnica were poor hosts (Rf < 1). In the Western Highland experiment, all arabica coffee accessions were susceptible for P. coffeae with Rf ranging from 1.41 to 1.59. Tolerance to P. coffeae was found in C. liberica var. Dewevrei, Hong34 and Nhuantren. Coffea excelsa, Hong34, Nhuantren, and H1C19 were tolerant to R. arabocoffeae at the highest inoculation density (4,000 nematodes/pot). The most susceptible accessions were Nhuantren and K55. Resistance (Rf < 1) to R. arabocoffeae was found in C. liberica var. Dewevrei and Hong34. This article reports on the first screening for resistance and tolerance to P. coffeae and R. arabocoffeae in coffee accessions in Vietnam and shows promising results for enhanced coffee-breeding.     

Mapping of new resistance (<Emphasis Type="Italic">Vr2</Emphasis>, <Emphasis Type="Italic">Rm1</Emphasis>) and ornamental (<Emphasis Type="Italic">Di2</Emphasis>, <Emphasis Type="Italic">pl</Emphasis>) Mendelian trait loci in peach

Peach powdery mildew is one of the major diseases of the peach. Various sources of resistance to PPM have thus been identified, including the single dominant locus Vr2 carried by the peach rootstock ‘Pamirskij 5’. To map Vr2, a linkage map based on microsatellite markers was constructed from the F₂ progeny (WP²) derived from the cross ‘Weeping Flower Peach’ × ‘Pamirskij 5’. Self-pollinations of the parents were also performed. Under greenhouse conditions, all progenies were scored after artificial inoculations in two classes of reactions to PPM (resistant/susceptible). In addition to Vr2, WP² segregated for three other traits from ‘Weeping Flower Peach’: Rm1 for green peach aphid resistance, Di2 for double-flower and pl for weeping-growth habit. With their genomic locations unknown or underdocumented, all were phenotyped as Mendelian characters and mapped: Vr2 mapped at the top of LG8, at 3.3 cM, close to the CPSCT018 marker; Rm1 mapped at the bottom of LG1, at a position of 116.5 cM, cosegregating with the UDAp-467 marker and in the same region as Rm2 from ‘Rubira’^®; Di2 mapped at 28.8 cM on LG6, close to the MA027a marker; and pl mapped at 44.1 cM on LG3 between the MA039a and SSRLG3_16m46 markers. Furthermore, this study revealed, for the first time, a pseudo-linkage between two traits of the peach: Vr2 and the Gr locus, which controls the red/green color of foliage. The present work therefore constitutes a significant preliminary step for implementing marker-assisted selection for the four major traits targeted in this study.     

High frequency direct plant regeneration from leaf and petals of Cape Primrose (<Emphasis Type="Italic">Streptocarpus</Emphasis>)

High frequency direct plant regeneration from leaf and petal explants was accomplished for the first time in Streptocarpus varieties. The shoot induction frequency varied with respect to the benzylaminopurine (BAP) concentration added to the Murashige and Skoog (MS) medium. MS medium with 0.5 mg l⁻¹ BAP exhibited the highest (69.9%) plant regeneration frequency with an average of 186 shoots per explant. A higher concentration of BAP inhibited shoot bud induction and plant regeneration along with necrosis of explants. Petal explants derived from the varieties ‘Branwen’ (pink and white) and ‘Chorus Line’ (violet and white) displayed plant regeneration frequency of 22.2–47.4% (within a total of 12 weeks) on MS medium containing 2.0 mg l⁻¹ α-naphthaleneacetic acid and 0.5 mg l⁻¹ BAP for 8 weeks followed by 4 weeks on MS medium with 1.0 mg l⁻¹ BAP. Scanning electron microscopy confirmed direct plant regeneration without callus. Regenerated plants from leaf explants with well-developed leaves and roots were hardened and successfully transferred to pots in glasshouse exhibiting 86% survival at the end of 4–6 weeks. Whereas, regenerated plants from flower petal explants upon transfer to pots in glasshouse exhibited 75–82% survival at the end of 4–6 weeks.     

IAA-producing <Emphasis Type="Italic">Klebsiella variicola</Emphasis> AY13 reprograms soybean growth during flooding stress

Soybean is known to be intolerant of waterlogged conditions. Flooding stress usually affects the crop via poor and retorted root development. The current study aimed to isolate indole acetic acid (IAA)-producing bacteria with potential to induce adventitious root growth and counteract flooding stress. The isolate AY-13 was identified as Klebsiella variicola using 16S DNA sequencing and phylogenetic analysis. A pure culture of AY-13 Klebsiella variicola was subjected to chromatography and mass spectrometry selected-ion monitoring (GC-MS/SIM) for IAA quantification. The results revealed the presence of (84.27±3.55 μg/mL) IAA in the AY-13 culture. The strain AY-13 was able to induce adventitious root initiation. Therefore, soybean seedlings were inoculated with AY-13 to examine its potential for promoting growth and reprograming after flooding stress. AY-13 application not only mitigated the flooding stress, but also significantly improved the plants’ growth, enhanced chlorophyll contents, and improved the quantum efficiency of chlorophyll fluorescence during and after flooding stress. Our findings were that AY-13 possesses great potential for mitigating flooding stress and improving soybean plant growth.     

Characterization of genes <Emphasis Type="Italic">Rpp2</Emphasis>, <Emphasis Type="Italic">Rpp4</Emphasis>, and <Emphasis Type="Italic">Rpp5</Emphasis> for resistance to soybean rust

Asian rust, caused by the fungus Phakopsora pachyrhizi, is the most severe disease currently threatening soybean crops in Brazil. The development of resistant cultivars is a top priority. Genetic characterization of resistance genes is important for estimating the improvement when these genes are introduced into soybean plants and for planning breeding strategies against this disease. Here, we infected an F₂ population of 140 plants derived from a cross between ‘An-76’, a line carrying two resistance genes (Rpp2 and Rpp4), and ‘Kinoshita’, a cultivar carrying Rpp5, with a Brazilian rust population. We scored six characters of rust resistance (lesion color [LC], frequency of lesions having uredinia [%LU], number of uredinia per lesion [NoU], frequency of open uredinia [%OU], sporulation level [SL], and incubation period [IP]) to identify the genetic contributions of the three genes to these characters. Furthermore, we selected genotypes carrying these three loci in homozygosis by marker-assisted selection and evaluated their genetic effect in comparison with their ancestors, An-76, PI230970, PI459025, Kinoshita and BRS184. All three genes contributed to the phenotypes of these characters in F₂ population and when pyramided, they significantly contributed to increase the resistance in comparison to their ancestors. Rpp2, previously reported as being defeated by the same rust population, showed a large contribution to resistance, and its resistance allele seemed to be recessive. Rpp5 had the largest contribution among the three genes, especially to SL and NoU. Only Rpp5 showed a significant contribution to LC. No QTLs for IP were detected in the regions of the three genes. We consider that these genes could contribute differently to resistance to soybean rust, and that genetic background plays an important role in Rpp2 activity. All three loci together worked additively to increase resistance when they were pyramided in a single genotype indicating that the pyramiding strategy is one good breeding strategy to increase soybean rust resistance.     

Production of interspecific hybrids between <Emphasis Type="Italic">Lilium longiflorum</Emphasis> and <Emphasis Type="Italic">L. lophophorum</Emphasis> var. <Emphasis Type="Italic">linearifolium</Emphasis> via ovule culture at early stage

Interspecific hybridization was carried out between Lilium longiflorum and L. lophophorum var. linearifolium by using the cut style method of pollination, as a contrast, intraspecific hybridization between L. longiflorum ‘Gelria’ and L. longiflorum was also made, but no mature seeds and offspring were obtained from the two combinations under in vivo condition. Ovules excised from each carpel 5–35 days after pollination (DAP) were cultured on B5 or half-strength B5 medium containing sucrose at different concentrations in vitro. In L. longiflorum × L. lophophorum var. linearifolium, only 1.17% of ovules excised at 10 DAP developed into seedlings, and in L. longiflorum ‘Gelria’ × L. longiflorum, only 0.99% of ovules excised at 25 DAP developed into seedlings; none of the ovules excised at other different DAP in the two cross combinations produced any seedlings. The results showed that interspecific hybridization had a more serious post-fertilization barrier than the intraspecific hybridization, and that a lower concentration (3%) of sucrose led to better embryo development and higher percentage of seedlings in ovule cultures. All hybrid seedlings obtained were successfully transplanted to soil and grew normally. The progenies investigated were identified as true hybrids based on inter-simple sequence repeat (ISSR) analysis.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated genetic transformation of pigeon pea [<Emphasis Type="Italic">Cajanus cajan</Emphasis> (L.) Millsp.] for resistance to legume pod borer <Emphasis Type="Italic">Helicoverpa armigera</Emphasis>

Agrobacterium-mediated genetic transformation was performed using embryonic axes explants of pigeon pea. Both legume pod borer resistant gene (cry1Ac) and plant selectable marker neomycine phosphor transferase (nptII) genes under the constitutive expression of the cauliflower mosaic virus 35S promoter (CaMV35S) assembled in pPZP211 binary vector were used for the experiments. An optimum average of 44.61% successfully hardened dot blot Southern hybridization positive plants were obtained on co-cultivation media supplemented with 200 μM acetosyringone without L-cysteine. The increased transformation efficiency from a baseline of 11.53% without acetosyringone to 44.61% with acetosyringone was further declined with the addition of different concentrations of L-cysteine to co-cultivation media. Transgenic shoots were selected on 50 and 75 mg L⁻¹ kanamycin. Rooting efficiency was 100% on half-strength Murashige and Skoog medium with 20 g L⁻¹ sucrose and 0.5 mg L⁻¹ indole butyric acid in the absence of kanamycin. Furthermore, 100% seed setting was found among all the transgenic events. The plants obtained were subjected to multi- and nochoice tests to determine the behavioral responses and mortality through Helicoverpa armigera bioassays on the leaf and relate their relationship with the expression of cry1Ac protein which was found to be less in leaf as compared to the floral buds, anther, pod, and seed.     

<Emphasis Type="Italic">In vivo</Emphasis> Acclimatization Responses of <Emphasis Type="Italic">Platycodon grandiflorum</Emphasis> For. Duplex to Different Soil Types and Environmental Factors

This study aimed to evaluate the effects of soil types and environmental factors for optimum conditions of seedlings growth of the Platycodon grandiflorum for establishing the in vivo acclimatization system of regenerated plants derived from the in vitro culture. P. grandflorum seedlings were transferred to the in vivo condition and acclimatized under different soil types, light intensities, and various temperatures. Changes caused by environmental factors and soil types in plant growth viz. plant height, leaf width, leaf length, stem diameter, number of leaves, branches and nodes were recorded in this study. Among the nine types of soil, the best growth performances were obtained from the soil type SVP (Soil mixed with horticultural bed soil, vermiculite, and perlite @ 2:1:1). Seedlings of P. grandiflorum showed the best growth at higher levels of light intensity (60 μmol·m^-2·s^-1). In contrast, P. grandiflorum seedlings showed the best growth response at a moderate level of temperature (25°C). Collectively, the present study provides a better understanding of the responses of growth characteristics in P. grandiflorum seedlings exposed to various soil types, light intensities, and temperatures.     

Modelling rice competition with <Emphasis Type="Italic">Echinochloa crus-galli</Emphasis> and <Emphasis Type="Italic">Eleocharis kuroguwai</Emphasis> in transplanted rice cultivation

Field experiments were conducted to investigate rice — Echinochloa crus-galli and rice — Eleocharis kuroguwai competition under transplanted rice cultivation in four major rice production areas; Suwon, Daejeon, Iksan, and Naju in Korea. Rice yield data were used to predict rice yield as a function of plant densities of E. crus-galli and E. kuroguwai using a rectangular hyperbola and to determine economic threshold (ET) levels of the weeds. Both weed species significantly reduced number of tillers at early rice growth stage, resulting in significant reduction in number of spikes, and the other yield components such as number of grains, maturity and 1,000-grain weight at later growth stage. The weed competitivity represented by parameter ranged from 0.0145 to 0.0346 for E. crus-galli and from 0.0037 to 0.0187 for E. kuroguwai, indicating that the competition effect of E. crus-galli on rice yield was slightly greater than that of E. kuroguwai. The ET values of E. crus-galli were between 0.298 and 1.078 plants m⁻², while those of E. kuroguwai were between 0.848 and 5.298 plants m⁻², depending on weed competitivity and herbicide price. Therefore, our results can be used to support decision-making on herbicide application for E. crus-galli and E. kuroguwai management in transplanted rice cultivation.     

Resistance to <Emphasis Type="Italic">Cucumber green mottle mosaic virus</Emphasis> in <Emphasis Type="Italic">Cucumis sativus</Emphasis>

Cucumber green mottle mosaic virus (CGMMV) is a severe threat for cucumber production worldwide. At present, there are no cultivars available in the market which show an effective resistance or tolerance to CGMMV infection, only wild Cucumis species were reported as resistant. Germplasm accessions of Cucumis sativus, as well as C. anguria and C. metuliferus, were mechanically infected with the European and Asian strains of CGMMV and screened for resistance, by scoring symptom severity, and conventional RT-PCR. The viral loads of both CGMMV strains were determined in a selected number of genotypes using quantitative RT-PCR. Severe symptoms were found following inoculation in C. metuliferus and in 44 C. sativus accessions, including C. sativus var. hardwickii. Ten C. sativus accessions, including C. sativus var. sikkimensis, showed intermediate symptoms and only 2 C. sativus accessions showed mild symptoms. C. anguria was resistant to both strains of CGMMV because no symptoms were expressed and the virus was not detected in systemic leaves. High amounts of virus were found in plants showing severe symptoms, whereas low viral amounts found in those with mild symptoms. In addition, the viral amounts detected in plants which showed intermediate symptoms at 23 and 33 dpi, were significantly higher in plants inoculated with the Asian CGMMV strain than those with the European strain. This difference was statistically significant. Also, the amounts of virus detected over time in plants did not change significantly. Finally, the two newly identified partially resistant C. sativus accessions may well be candidates for breeding programs and reduce the losses produced by CGMMV with resistant commercial cultivars.