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1.
2.
Tissa Senaratna Bryan D. McKersie Stephen R. Bowley 《In vitro cellular & developmental biology. Plant》1990,26(1):85-90
Summary The use of somatic embryos from cell culture systems in the clonal propagation of plants would be greatly facilitated if the
somatic embryos could be dried and stored in a dormant state similar to true seeds. A cell culture system was developed for
alfalfa (Medicago sativa L.) line RL34 which gave high yields of somatic embryos in an approximately synchronized pattern. These somatic embryos were
treated with abscisic acid (ABA) at the cotyledonary stage of development to induce desiccation tolerance. With no visual
preselection, approximately 60% of the dried embryos converted into plants upon reimbibition. When high quality embryos were
selected prior to drying, 90 to 100% conversion rates were observed. The timing of the application of ABA in terms of embryo
development was critical with an optimum being at cotyledonary stage spanning approximately 4 days; thus, synchronized embryo
development is required for optimal expression in bulk samples. The vigor of the seedlings from dried somatic embryos was
greater than those from embryos which had not been dried, but remained substantially lower than those from true seeds. 相似文献
3.
Water-Deficit Tolerance and Field Performance of Transgenic Alfalfa Overexpressing Superoxide Dismutase 总被引:29,自引:1,他引:28
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Transgenic alfalfa (Medicago sativa) expressing Mn-superoxide dismutase cDNA tended to have reduced injury from water-deficit stress as determined by chlorophyll fluorescence, electrolyte leakage, and regrowth from crowns. A 3-year field trial indicated that yield and survival of transgenic plants were significantly improved, supporting the hypothesis that tolerance of oxidative stress is important in adaptation to field environments. 相似文献
4.
The trait for somatic embryogenesis is being introduced sexually into alfalfa (Medicago sativa) breeding populations to facilitate genetic transformation of this crop. Cocultivation experiments were conducted with an agronomically-improved embryogenic clone from one such population as well as with two other embryogenic clones, one of which was the source of the embryogenic trait in the breeding populations. Transgenic plants were produced from the agronomically-improved clone whereas none were produced from the other two clones. Among the 16 transgenic plants analyzed there was a range in both copy number and number of integration sites for the NPT-II gene; those plants regenerated after a prolonged selection phase in vitro generally had the highest numbers in both respects. There was no evidence of sectoral chimerism of the transgene in a subsample of transgenic plants analyzed by PCR. 相似文献
5.
Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes 总被引:1,自引:0,他引:1
This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings. 相似文献
6.
TERESA MARYAKA HALSZKA OSMÓLSKA 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1979,12(3):265-273
Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed. 相似文献
7.
The effects of acute ethanol feeding and of chronic benfluorex administration on the activities of some enzymes of glycerolipid synthesis in rat liver and adipose tissue.
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P H Pritchard M Bowley S L Burditt J Cooling H P Glenny N Lawson R G Sturton D N Brindley 《The Biochemical journal》1977,166(3):639-642
Activation of adenylate cyclase in isolated rat liver plasma membranes by cholera toxin was demonstrated. The activation requires the presence of NAD+ and ATP and is irreversible. 相似文献
8.
9.
The paper presents multiplex panels of polymorphic microsatellites for two closely related cryptic species Pipistrellus pipistrellus and Pipistrellus pygmaeus. We tested the cross‐species amplification of 34 microsatellite loci, originally developed for five vespertilionid bat species. Ten and nine polymorphic loci in P. pipistrellus (mean number of alleles per locus = 10.5) and P. pygmaeus (8.1), respectively, in three multiplex polymerase chain reactions per species were amplified. All loci can be analysed in a single fragment analysis and can be used as markers to the study of evolution and the ecology of structured populations of socially living bats. 相似文献
10.