细化搜索
结果 1-10 的 4,429
Stresses in rice during moisture adsorption determined by the finite element method
1994
Lan, Y. | Kunze, O.R.
Nuclear DNA content of the Solanum spp. in the series Etuberosa as determined by laser flow cytometry
1994
Valkonen, J.P.T. (Department of Plant Pathology, Cornell University, Ithaca, NY 14853 (USA))
Properties of rescued embryonal suspensor masses of Norway spruce determined by the genotype and the environment in vitro. 全文
1994
Jokinen, Kari | Durzan, Don
53 genotypes of embryonal suspensor masses (ESMs) rescued from mature seeds of Norway spruce ( (L.) H. Karst.) were examined for their pattern of growth and development under standardized culture conditions . Patterns were classified according to the colour of the colonies grown in darkness, clarity of cell masses and proembryos in the mucilaginous ESM, surface boundary topology of colonies, structure of suspensors, growth rate of the ESM, and recovery of mature embryos.Picea abiesin vitro
显示更多 [+] 显示较少 [-]Properties of rescued embryonal suspensor masses of Norway spruce determined by the genotype and the environment in vitro. 全文
1994
Jokinen, Kari J. | Durzan, Don J. | The Finnish Society of Forest Science | Suomen metsätieteellinen seura | Finlands Forstvetenskapliga Samfund
Fifty three genotypes of embryonal suspensor masses (ESMs) rescued from mature seeds of Norway spruce (Picea abies L. Karst.) were examined for their pattern of growth and development under standardized culture conditions in vitro. Patterns were classified according to the color of the colonies grown in darkness, clarity of cell masses and proembryos in the mucilaginous ESM, surface boundary topology of colonies, structure of suspensors, growth rate of the ESM, and recovery of mature embryos. Five distinctive major growth patterns were observed among ESM colonies under standardized culture conditions. The multiplication of proembryos and early embryos by cleavage and budding polyembryony was the main factor contributing to proliferation and colony growth and further determined the morphology of the colonies. Callus and teratological structures were induced from early embryos by changing the standardized culture conditions i.e. inadequate subculture, excessive dose of 2,4-D in the medium and premature exposure of the colonies to light. Results enable the selection of ESM genotypes for the more predictable recovery of mature somatic embryos.
显示更多 [+] 显示较少 [-]Properties of rescued embryonal suspensor masses of Norway spruce determined by the genotype and the environment in vitro 全文
1994
Jokinen, Kari J. | Durzan, Don J. | Kemira Agro Oy | University of California
The distribution of inorganic constituents in white birch [Betula platyphylla] wood as determined by SEM-EDXA
1994
Saka, S. (Kyoto Univ. (Japan). Coll. of Agriculture) | Mimori, R.
Properties of rescued embryonal suspensor masses of Norway spruce determined by genotype and the environment in vitro
1994
Jokinen, K.J. (Kemira Argo Oy, Espoo (Finland). Espoo Research Centre) | Durzan, D.J.
The determined state of white expression in the Drosophila eye is modified by zeste(1) in the w(zm) family of mutants
1994
Peterson, K.M. (National Inst. of Environmental Health Science, Research Triangle Park, NC (USA). Lab. of Genetics) | Davis, P.S. | Judd, B.H.
Analysis of the white(zeste mottled) (W(zm)) mutant family suggests that the zeste gene product functions in establishing and stabilizing a transeriptionally active chromatin domain for white locus expression. The z(1) mutation reduces expression of paired or proximate copies of white, while single or unpaired copies maintain wildtype levels of expression. The w(zm) mutation, caused by the insertion of the retrotransposon BEL into the 5' intron of white, alters the zeste-white interaction to produce a mottled eye phenotype in hemizygous z(1) w(zm) males. The molecular structure of four w(zm) derivatives was determined. w(zl) results from the insertion of an additional transposable element into the 5' regulatory region of white. w(zvl) is a deletion of sequences upstream of the white locus. Two others, w(halo) and w(cres), result from the transposition of w(zm) plus the entire verticals-roughest region into heterochromatin near the tip of chromosome 3L. They variegate for roughest but not for white; rather, the z(1) effect on w(zm) now causes white expression to become non-autonomous and non-clonal. The analysis of these five mutations shows that the neomorphic zeste(1) product, in combination with structural changes imposed by transposons and intercalary heterochromatin, modifies the determination and stability of white expression. It is proposed that the normal zeste product functions as part of a complex that stimulates transcription by changing chromatin conformation to establish and maintain transcriptionally active domains. The unpairing of homologs is proposed to be one of the initial results of conformational change, providing an explanation for the role of zeste in transvection.
显示更多 [+] 显示较少 [-]Endogenous ileal nitrogen flow in pigs determined using the 15N-isotope dilution and peptide alimentation ultrafiltration methods.
1994
Schulze, H. | Butts, C.A. | Moughan, P.J. | Verstegen, M.W.A.
The cyclic electron pathways around photosystem I in Chlamydomonas reinhardtii as determined in vivo by photoacoustic measurements of energy storage
1994
Ravenel, J. | Peltier, G. | Havaux, M.
The photoacoustic technique was used to measure energy storage by cyclic electron transfer around photosystem I in intact Chlamydomonas reinhardtii cells illuminated with far-red light (>715 nm). The in-vivo cyclic pathway was characterized by investigating the effects of various chemicals on energy storage. Participation of plastoquinone and ferredoxin in the cyclic electron flow was confirmed by the complete suppression of energy storage in the presence of the plastoquinol antagonist 2,5-dibromo-3-methyl-6-isopropyl-p benzoquine (DBMIB) and the ferredoxin inhibitors/competitors methylviologen, phenylmercuric acetate and p-benzoquinone. Two alternative electron cycles are demonstrated to operate in vivo. One cycle is sensitive to antimycin A, myxothiazol and 2-(n-heptyl)-4-hydroxyquinoline N-oxide (HQNO) and is catalyzed by ferredoxin which reduces plastoquinone through a route involving cytochrome b6 and its protonmotive Q-cycle. The other cycle is unaffected by the above-mentioned inhibitors but is sensitive to N-ethylmaleimide (NEM), an inhibitor of the ferredoxin-NADP reductase, and 2'-monophosphoadenosine-5'-diphosphoribose (PADR), an analogue of NADP, showing that the electron recycling was mediated by NADPH. Possibly, electrons enter the plastoquinone pool through the action of a NAD(P)H dehydrogenase, which is insensitive to classical inhibitors of the mitochondrial NADH dehydrogenase. Loss of energy storage by photosystem-I-driven cyclic electron transfer in far-red light was observed only when antimycin A, myxothiazol or HQNO was used in combination with NEM or PADR. Analysis of the light-intensity dependence and the rate of in-vivo cyclic electron transfer in the presence of various inhibitors indicates that the NADPH-dependent electron-cycle is the preferential cyclic pathway in Chlamydomonas cells illuminated with far-red light.
显示更多 [+] 显示较少 [-]