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981.
The effects of temperature and pressure on the characteristics of the extracts from high-pressure CO(2) extraction of Majorana hortensis Moench 总被引:1,自引:0,他引:1
Rodrigues MR Caramão EB dos Santos JG Dariva C Oliveira JV 《Journal of agricultural and food chemistry》2003,51(2):453-456
The aim of this work is to assess the influence of temperature and pressure (solvent density) on the characteristics of the essential oil obtained from high-pressure carbon dioxide extraction of marjoram (commercial marjoram samples available in the free market and Majorana hortensis Moench, cultivated in South Brazil under rigorous agronomic conditions). The extracts were analyzed in terms of the liquid yield (extract/raw material, wt/wt) and distribution of volatile chemical components. The experiments were performed in a laboratory-scale unit using the dynamic method in the temperature range of 293.15-313.15 K, from 100 to 200 bar in pressure. Chemical analyses were carried out in a GC/MSD. Results show that an increase in temperature leads to a rise in the extract liquid yield despite large changes in solvent density. Chromatographic analyses permitted the identification of cis-sabinene hydrate, terpineol-4, alpha-terpineol, and cis-sabinene hydrate acetate as the main volatile compounds present in both commercial and cultivated samples. 相似文献
982.
Further studies on the anticancer activity of citrus limonoids 总被引:8,自引:0,他引:8
Miller EG Porter JL Binnie WH Guo IY Hasegawa S 《Journal of agricultural and food chemistry》2004,52(15):4908-4912
Research in this laboratory has shown that some citrus limonoids can inhibit the development of 7,12-dimethylbenz[a]anthracene-induced oral tumors. The data from these studies have suggested that certain rings in the limonoid nucleus may be critical to antineoplastic activity. Using the hamster cheek pouch model, three new limonoids (ichangensin, deoxylimonin, and obacunone) have now been tested for cancer chemopreventive activity. In the first experiment, it was found that the treatments with ichangensin had no effect on tumor number or burden. In the second experiment, obacunone reduced tumor number and burden by 25 and 40%, respectively, whereas deoxylimonin reduced tumor number and burden by 30 and 50%, respectively. The results with deoxylimonin were significant, p < 0.05. Overall, the data indicated that changes in the A ring of the limonoid nucleus can lead to a loss of anticancer activity, whereas changes in the D ring can be tolerated without any apparent loss of biological activity. 相似文献
983.
Much of the literature on the location of producer services is concerned with their uneven spatial development across regions. Although this approach is useful, it proves to be limited, and a complementary analytical framework is required. This paper uses data from France's Annual Survey of Services to address producer service location from a novel perspective, that of the firm. A basic distinction is made between single site (compact) and multisite (network) producer service firms, and the natures of these two types are analyzed in terms of business strategies, location and performance. Further analyses are then based upon the distinctions between sales and servuction networks, and between specialized and diversified networks. Although significant for producing higher output levels, a network structure does not necessarily ensure a higher level of profitability. 相似文献
984.
In this study, two microsatellite-based methodologies (SSR and ISSR) were evaluated for potential use in fingerprinting and
determination of the similarity degree between 41 commercial cultivars of apple previously characterised using RAPD and AFLP
markers. A total of 13 SSR primer sets was used and 84 polymorphic alleles were amplified. Seven ISSR primers yielded a total
of 252 bands, of which 176 (89.1%) were polymorphic. Except for cultivars obtained from somatic mutations, all cultivars were
easily distinguishable employing both methods. The similarity coefficient between cultivars ranged from 0.20 to 0.87 for SSR
analysis and from 0.71 to 0.92 using the ISSR methodology. Dendrograms constructed using UPGMA cluster analysis revealed a
phenetic classification that emphasises the existence of a narrow genetic base among the cultivars used, with the Portuguese
cultivars revealing higher diversity. This study indicates that the results obtained based on the RAPD, AFLP, SSR and ISSR
techniques are significantly correlated. The marker index, based on the effective multiplex ratio and expected heterozygosity,
was calculated for both analyses (MI = 1.7 for SSR and MI = 8.4 for ISSR assays) and the results obtained were directly compared
with previous RAPD and AFLP data from the same material. The SSR and ISSR markers were found to be useful for cultivar identification
and assessment of phenetic relationships, revealing advantages, due to higher reproducibility, over other commonly employed
PCR-based methods, namely RAPD and AFLP.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
985.
Kuzumitsu Matsumoto Milena Luz Barbosa Luiz Augusto Copati Souza João Batista Teixeira 《Euphytica》1995,84(1):67-71
Summary The selection of tolerant variants to race 1 fusarium wilt of banana was carried out through the effects of fusaric acid onin vitro banana multiple bud clumps (MBCs). The MBCs of Maçã cultivar (Musa sp., AAB, Silk), which is susceptible to the race 1 fusarium wilt, were used. And, Nanicão cultivar (AAA, Cavendish subgroup) was used in the tolerant tests as control of a disease tolerant variety. Firstly, to aim at determining an appropriate concentration of the toxin for the tolerant selection, the MBCs were cultured on the Modified Murashige & Skoog medium supplemented with 0.05 to 1.6 mM fusaric acid. The growth on both cultivars was completely inhibited on the medium containing 0.1 mM fusaric acid.Tolerant variants of Maçã were, then, selected with 0.1 mM fusaric acid after chemical mutagen treatment. The results showed an increased tolerance of the selected Maçã plants to the race 1 fungus in greenhouse tests.
In vitro selection by fusaric acid is a very useful method for obtaining fusarium disease tolerance, although the tolerance mechanism of the selected plants may be different from that of existing tolerant cultivars. 相似文献
986.
Magno Antonio Patto Ramalho Ângela de Fátima Barbosa Abreu João Bosco dos Santos 《Euphytica》2005,144(1-2):23-29
The objective of this study was to evaluate the genetic progress after four cycles of recurrent selection in common bean.
The base segregating population was obtained from 10 parents, and derived the S0:1 and S0:2 families that were evaluated. The S0:3 families with higher grain yield and grain color, like the standard carioca were selected, and were intercrossed to generate
the population of the following cycle. This process was repeated for four cycles. The best families were evaluated in each
cycle by many generations and locations, and the five best lines of each cycle were identified. The 20 lines thus obtained
were evaluated in two growing seasons, sown in July and November 2002. The grain yield (kg/ha) and grain type (scale of scores)
were evaluated. Genetic progress was confirmed for both traits. The mean annual gain with selection for the grain type was
10.5% and 5.7% for grain yield, with no evidence of variability reduction in the population. These results show that recurrent
selection is a good alternative for improving common bean quantitative traits. 相似文献
987.
Common bean (Phaseolus vulgaris L.), an important food crop in Europe, America, Africa and Asia, is thought to fix only small amounts of atmospheric nitrogen.
It contributes significantly to the sustainability of traditional cropping systems because of the predominance of small-scale
farmers who cultivate beans in those areas. The objectives of this work were to evaluate bush bean varieties under common
agronomic cropping systems and to evaluate breeding lines under low N-fertility sole cropping and intercropping systems. The
purpose of the study was to characterize the genotype and cropping system's variability in symbiotic and plant characters
and to identify the most suitable genotypes to establish an effective symbiosis with indigenous strains of Rhizobium. No significant differences among the bush bean varieties evaluated under typical fertilization practices were observed for
N2-fixation and plant traits except for seed nitrogen. Significant differences among the bean lines studied under low N-fertilization
conditions were detected for plant growth,plant component and N2-fixation traits. A significant interaction of bean genotype x cropping system was found for number of nodules per plant and
nodule moisture on the bush bean varieties studied, and for days to emergence, days to flowering, end of flowering, shoot
length, root dry weight and shoot nitrogen on the bean lines evaluated. Nodulation parameters were correlated positively with
the yield components, shoot and root parts and duration of flowering, and correlated negatively with seed crude protein, pod
and seed dimensions and seed dry weight. These observations indicate that it may be possible to increase both the symbiotic
N2-fixation and seed yield through plant breeding.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
988.
Jo?o?A.?Wordell?FilhoEmail author Francisco?X.?R.?Vale Ariano?M.?Prestes Laércio?Zambolim 《Euphytica》2005,142(3):217-225
Resistance of 59 barley cultivars to three distinct isolates of Bipolaris sorokiniana, causing brown leaf spot was tested on seedlings and adult plants in a screen house and in a growth room, by determination of disease incidence, disease severity, and rate of lesion expansion. The disease reaction and severity at the seedling stage differed among cultivars. The cultivars MNS Brite, NDB 112, Kindred, Parkland, and Oderbrucke were moderately resistant to brown leaf spot, but the resistance was partial to all three isolates. None genotype with complete resistance was found. The cultivars CI 9539, Svanhals, and Chevron, considered as sources of resistance, were classified as moderately susceptible, and susceptible, respectively. Disease severity, disease reaction, and incidence of B. sorokiniana in grains also differed among the cultivars at the adult plant stage. Nevertheless, none of the genotypes was resistant to B. sorokiniana. The rate of lesion expansion differed among cultivars BR 2, MN 698, Kitchin, Svanhals, and NDB 112, with NDB 112 having the slowest expansion rate (0.194–0.205 mm2/day). 相似文献
989.
990.
Monção Flávio Pinto Costa Marco Aurélio Morais Soares Rigueira João Paulo Sampaio de Sales Eleuza Clarete Junqueira Leal Dijair Barbosa da Silva Marcos Felipe Pereira Gomes Virgílio Mesquita Chamone Julieta Maria Alencar Alves Dorismar David da Cunha Siqueira Carvalho Cinara Murta José Eduardo Jardim Júnior Vicente Ribeiro Rocha 《Tropical animal health and production》2020,52(1):235-241
Tropical Animal Health and Production - The objective of this study was to evaluate the productivity, productive efficiency, and nutritional value of the elephant grass cultivar BRS capiaçu... 相似文献