Somatic embryo production and plant regeneration of Japanese black pine (Pinus thunbergii)     

Emilio Maruyama  Yoshihisa Hosoi  Katsuaki Ishii 《Journal of Forest Research》2005,10(5):403-407

Somatic embryogenesis in Pinus thunbergii was initiated from megagametophytes containing immature zygotic embryos. Embryogenic cultures were maintained and proliferated in medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. High maturation frequencies of somatic embryos were obtained on maturation media containing maltose, activated charcoal, abscisic acid, and polyethylene glycol as osmotic agent. The best result among the cell lines tested was achieved with the cell line T-205-3. More than 900 somatic embryos per petri dish, on average, were obtained after about 8 weeks of culture on maturation medium. Sixty percent of somatic embryos tested germinated after transfer to plant growth regulator-free medium and then 85% of them converted into plantlets.  相似文献   

Preparation of 2H-furo[2,3-c]pyran-2-one derivatives and evaluation of their germination-promoting activity     

Flematti GR  Goddard-Borger ED  Merritt DJ  Ghisalberti EL  Dixon KW  Trengove RD 《Journal of agricultural and food chemistry》2007,55(6):2189-2194

The butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one (1), has recently been identified as the germination stimulant present in smoke that promotes the germination of seeds from a wide range of plant species. In this paper, we describe the preparation of a number of analogues of 1 and compare their efficacy in promoting seed germination of three highly smoke-responsive plant species, Lactuca sativa L. cv. Grand Rapids (Asteraceae), Emmenanthe penduliflora Benth. (Hydrophyllaceae), and Solanum orbiculatum Poir. (Solanaceae). The results show that the methyl substituent at C-3 in 1 is important for germination-promoting activity while substitution at C-7 reduces activity. In contrast, bioactivity is mostly retained with analogues substituted at C-4 or C-5.  相似文献   

Cytotoxic resveratrol oligomers from the tree bark of Dipterocarpus hasseltii     

Muhtadi  Hakim EH  Juliawaty LD  Syah YM  Achmad SA  Latip J  Ghisalberti EL 《Fitoterapia》2006,77(7-8):550-555

A new resveratrol tetramer, named diptoindonesin E, was isolated from the acetone extract of the tree bark of Dipterocarpus hasseltii, together with five known resveratrol oligomers (-)-epsilon-viniferin, laevifonol, (-)-alpha-viniferin, vaticanol B, (-)-hopeaphenol, and a coumarin, scopoletin. The structures of these compounds were determined from spectroscopic evidence. Cytotoxicity test of the isolated compounds showed that hopeaphenol strongly inhibited murine leukemia P-388 cells.  相似文献   

Venturia inaequalis resistance in local Spanish cider apple germplasm under controlled and field conditions     

Alejandro Martínez-Bilbao  Amaya Ortiz-Barredo  Emilio Montesinos  Jesús Murillo 《Euphytica》2012,188(2):273-283

Host resistance is a key method for the integrated management of apple scab caused by Venturia inaequalis, which is one of the most important diseases of apple. Artificial inoculation of 92 cider apple cultivars with a mixed inoculum of V. inaequalis identified 19 weakly resistant and 19 resistant cultivars. Twelve of these resistant cultivars were previously classified as having low susceptibility to fire blight, and four of them showed complete or weak resistance to races (1), (1, 6) and (6, 7, 13) of V. inaequalis. The analysis of a selection of 72 cultivars for 6 years under field conditions identified 14 cultivars that were classified as resistant to apple scab under high disease pressure involving one to six Mills periods of severe risk of infection each year. Eight out of these 14 cultivars previously showed high levels of resistance to fire blight, which would allow the incorporation of genetic resistance in the integrated production of cider apples in Spain through their use in breeding programs.  相似文献   

Cover crops under different managements vs. frequent tillage in almond orchards in semiarid conditions: Effects on soil quality   总被引：1，自引：0，他引：1  

María E. Ramos  Emilio Benítez  Pedro A. García  Ana B. Robles 《Applied soil ecology》2010,44(1):6-14

Frequent tillage has been widely used in rainfed orchards in SE Spain in order to impede weed establishment and to increase water reposition in the soil profile. However, this practice may lead to soil degradation by decreasing structural stability, organic carbon content and microbial activity. This work examines the effect of different cover crop managements and frequent tillage on soil physical, chemical and biological properties in almond orchards in SE Spain. Two cover crops (oat – Avena sativa L. and oat-vetch – Vicia sativa L.) with two fertilization managements (mineral and organic) and three harvesting regimes (grazing in mid May, hay in early June, and grain-straw in mid July) were compared to a frequently tilled orchard system (three or four tillages per year). Most parameters were sensitive to soil management. Wet aggregate stability, total organic carbon, total nitrogen, carbon:nitrogen ratio, phosphatase, and β-glucosidase activities increased with cover crops, whereas the soil–water content declined, especially for the grain-straw treatment. The kind of fertilizer affected the available P content, which was higher for mineral fertilizer, and influenced the β-glucosidase activity, which augmented for the organic fertilizer. Livestock dejections depressed phosphatase activity, and increased WSC and available P.This study suggests that cover crops in semiarid environments improve soil quality compared to frequently tilled management, by increasing the organic matter content, improving the chemical and physical fertility of the soil, and enhancing the soil biological activity. Only higher water extraction by the plants could affect the orchard development and/or productivity; however, early cover crop removal would minimize possible yield losses.  相似文献   

Nutritional reference values for Opuntia ficus‐indica determined by means of the boundary‐line approach     

Fidel Blanco‐Macías  Rafael Magallanes‐Quintanar  Ricardo D. Valdez‐Cepeda  Rigoberto Vázquez‐Alvarado  Emilio Olivares‐Sáenz  Erasmo Gutiérrez‐Ornelas  Juan A. Vidales‐Contreras  Bernardo Murillo‐Amador 《植物养料与土壤学杂志》2010,173(6):927-934

Optimum concentrations and/or sufficiency ranges of nutrients are useful for a correct diagnosis and improvement of nutrient status of cultivated plants. To develop boundary‐line approach (BLA) standards for Opuntia ficus‐indica L., a database of N, P, K, Ca, and Mg concentrations in 1‐year‐old cladodes and cladodes fresh‐matter yield was used. The BLA optimum concentrations (associated with estimated maximum yield) for O. ficus‐indica were: N = 13.1 g kg^–1, P = 3.2 g kg^–1, K = 44.4 g kg^–1, Ca = 38.1 g kg^–1, and Mg = 17.3 g kg^–1. The BLA sufficiency ranges at 95% yield were 8.4–20.3 g kg^–1 for N, 2.4–4.2 g kg^–1 for P, 38.2–50.8 g kg^–1 K, 31.8–45.2 g kg^–1 for Ca, and 14.3–20.9 g kg^–1 for Mg. The BLA standards are comparable to those obtained in a previous study using compositional‐nutrient‐diagnosis (CND) approach.  相似文献   

Occurrence of Cucurbit Yellow Stunting Disorder Virus (CYSDV) and Beet Pseudo-yellows Virus in Cucurbit Crops in Spain and Transmission of CYSDV by Two Biotypes of Bemisia tabaci   总被引：3，自引：0，他引：3  

Benjamín Berdiales  Juan J. Bernal  Elisa Sáez  Bert Woudt  Francisco Beitia  Emilio Rodríguez-Cerezo 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(2):211-215

The relative occurrence in Spain of two whitefly transmitted closteroviruses causing similar yellowing diseases in melon and cucumber greenhouse crops was studied. Based on a RT-PCR assay, a 1994–1997 survey of Spanish greenhouses showed that the recently described Bemisia tabaci-transmitted cucurbit yellow stunting disorder virus (CYSDV) has displaced the Trialeurodes vaporariorum-transmitted beet pseudo-yellows virus (BPYV), a virus that was present in the area since the late 1970s. The CYSDV transmission rates by each of the two biotypes of B. tabaci present in Spain were compared. The results showed that the ubiquitous B biotype and the resident Q biotype (found in Spain and Portugal) were able to transmit CYSDV with similar efficiency.  相似文献   

Quantitative modification of the testicular structure in pigs fed with anabolic doses of clenbuterol     

Blanco A  Artacho-Pérula E  Flores-Acuña R  Agüera E  Monterde JG 《Veterinary research》2002,33(1):47-53

Morphological and structural data of the testes of thirty male pigs were recorded in order to evaluate the effects of an anabolic clenbuterol treatment. Pigs aged 6 months were randomly allocated to one of three experimental groups. In two treated groups, the animals were fed with anabolic doses of clenbuterol (1 ppm); in the CLB group (n = 10) clenbuterol was given until they were slaughtered (treatment period = 3 months) whereas in the CLBW group (n = 10) the clenbuterol was withdrawn two weeks before slaughter (treatment period = 2.5 months); clenbuterol was not given to the pigs of the control group (n = 10). Stereological estimations of the tissular volume fraction and tubular volume density were applied to quantify the structural constituents of the testes. The results showed an increased volume fraction of the testicular interstitium especially in the Leydig cell population, as a result of the clenbuterol treatment. The increase in the nuclear volume fraction of the Leydig cells was the more persistent change in the variations recorded in both treated groups with respect to the control. A regression of the seminal epithelium was also recorded in the treated animals. The rest of the structural parameters were closer to the normal figures in the CLBW group, suggesting a recovery of the testicular structure when clenbuterol was withdrawn.  相似文献   

The Chlamydomonas genome reveals the evolution of key animal and plant functions   总被引：1，自引：0，他引：1  

Merchant SS  Prochnik SE  Vallon O  Harris EH  Karpowicz SJ  Witman GB  Terry A  Salamov A  Fritz-Laylin LK  Maréchal-Drouard L  Marshall WF  Qu LH  Nelson DR  Sanderfoot AA  Spalding MH  Kapitonov VV  Ren Q  Ferris P  Lindquist E  Shapiro H  Lucas SM  Grimwood J  Schmutz J  Cardol P  Cerutti H  Chanfreau G  Chen CL  Cognat V  Croft MT  Dent R  Dutcher S  Fernández E  Fukuzawa H  González-Ballester D  González-Halphen D  Hallmann A  Hanikenne M  Hippler M  Inwood W  Jabbari K  Kalanon M  Kuras R  Lefebvre PA  Lemaire SD  Lobanov AV 《Science (New York, N.Y.)》2007,318(5848):245-250

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the approximately 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.  相似文献   

Alkylating potential of potassium sorbate     

Pérez-Prior MT  Manso JA  García-Santos Mdel P  Calle E  Casado J 《Journal of agricultural and food chemistry》2005,53(26):10244-10247

A kinetic study of the alkylating potential of potassium sorbate (S)-a food preservative used worldwide-in 7:3 water/dioxane medium was performed. The following conclusions were drawn: (i) Potassium sorbate shows alkylating activity on the nucleophile 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilic characteristics similar to those of DNA bases, (ii) The NBP alkylation reaction complies with the rate equation r = k(alk)[H+][S][NBP]/(K(a) + [H+]), K(a) being the sorbic acid dissociation constant and k(alk) the rate constant of NBP alkylation by the undissociated acid. In the range of pH 5-6, the alkylation time ranges between 18 days (pH 5.2) and >1 month (pH > or = 6). (iii) NBP alkylation occurs through a reaction with deltaH# = 78 kJ mol(-1), which is much higher than those of NBP alkylation by stronger alkylating agents. (iv) The absorption coefficient of the sorbate-NBP adduct was determined to be epsilon = 204 M(-1) cm(-1) (lambda = 580 nm), this value being rationalized in terms of the adduct structure. (v) The results can help to establish suitable expiration times for products preserved with potassium sorbate.  相似文献