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排序方式: 共有113条查询结果,搜索用时 15 毫秒
1.
Chloroplast Protein Synthesis During Barley Leaf Growth and Senescence: Effect of Leaf Excision 总被引:1,自引:0,他引:1
MART?N MERCEDES; URTEAGA BLANCA; SABATER BARTOLOM? 《Journal of experimental botany》1986,37(2):230-237
Chloroplast protein synthesis was measured during the expansion,maturity and senescence of the oldest leaf of barley, Hordeumvulgare L., var. Hassan. A maximum rate of protein synthesisoccurred near the end of the expansion stage 9 d after sowing.Protein synthesis increased again at the beginning of senescenceand reached a new maximum at day 14 after sowing. Detachmentand incubation of leaves in the dark stimulated chioroplastprotein synthesis by fully expanded or by senescent leaves butnot by expanding leaves. If the detached leaves were kept inthe light, chloroplast protein synthesis was stimulated in fullyexpanded but not in senescent leaves. Short treatments (18 h)of leaf segments with growth substances in either light or indarkness, significantly changed the rate of protein synthesisshown by chloroplasts. The relationship between chloroplastprotein synthesis and leaf senescence is discussed. Key words: Hormones, light, maturity 相似文献
2.
D. RIVERA NUÑEZ C. OBON DE CASTRO F. TOMAS-LORENTE F. FERRERES F. A. TOMAS BARBERAN 《Botanical journal of the Linnean Society. Linnean Society of London》1990,103(4):325-349
RIVERA NUÑEZ, D., OBON DE CASTRO, C., TOMAS-LORENTE, F., FERRERES, F. & TOMAS-BARBERAN, F. A., 1990. Infrasectional systematics of the genus Sideritis L. section Sideritis (Lamiaceae). A new taxonomic division of the section Sideritis is proposed on the basis of morphological, cytological and chemical characters. The following subsections art-recognized: Grandiflora, Ovata, Camarae, Linearifolia, Gymnocarpae, Stachydioides, Lacaitae, Hirsuta, Chamaedryfolia, Arborescens, Flavovirens, Leucantha, Angustifolia, Serrata and Scordioides . Possible evolutionary pathways are discussed. 相似文献
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NOEMÍ CASTRO FRANCISCO D. BARBIERI DORA C. MICELI CHRISTIANE DOSNE PASQUALINI 《Development, growth & differentiation》1984,26(5):427-434
Mouse early embryos and embryo fragments were transplanted into an immunologically privileged site, consisting of a glass cylinder previously implanted under the skin of adult mice in order to test their tumor producing potential, in allogeneic adult recipients. The highest yield of tumors was obtained upon transplantation of 6 1/2 day old embryos in toto. i.e., including the embryonic and extraembryonic areas. Histological examination showed teratomas composed of differentiated tissues derived from the three germ layers containing isolated foci of undifferentiated cells and nodules of trophoblast giant cells. Areas exhibiting the histological appearance of yolk sac carcinoma were also observed. Transplantation of the whole 6 1/2 day old egg cylinder, including the ectoplacental cone, and the isolated embryonic area produced a lower incidence of teratomas with a reduced variety of differentiated tissues. No yolk sac carcinoma was found in these grafts. The ectoplacental cone of 6 1/2 day embryos produced no tumors. Grafts of genital ridges from 12 1/2 day embryos gave rise to teratomas with well differentiated tissues of embryonic and extraembryonic origin. Areas ressembling yolk sac carcinoma were also observed. The life span of trophoblastic giant cells within the glass cylinder was significantly longer than in other experimental systems. 相似文献
5.
D. W. DUSZYNSKI S. A. ROY J. STEWERT G. A. CASTRO 《The Journal of eukaryotic microbiology》1978,25(3):370-374
SYNOPSIS. Experiments were designed to test whether or not intestinal transit time increases significantly during severe coccidiosis in the rat. Intraduodenal catheters were surgically implanted into 25 rats. Six to 12 days after surgery 11 rats were inoculated orally with 104 sporulated oocysts of Eimeria nieschulzi Dieben, and 11 were inoculated with 106 oocysts; 3 rats were retained as uninfected controls. At 2, 4, 8, 9, and 16 days postinoculation (PI) Na251CrO4 was injected through the catheter into the duodenum of fasted rats and allowed to progress through the small bowel for 15 min, at which time the rats were killed. The distribution of 51Cr in the gut was plotted as a function of gut length. The leading edge of radioactivity traversed 70% of the gut length in controls, and ~ 50–60% in parasitized rats on days 2, 4, 8, and 9 PI. Also, a reflux of gut contents, as evidenced by radioactivity in the stomach, occurred early (PI days 2 & 4) in rats infected with 104 oocysts and throughout patency in rats infected with 106 oocysts. A 2nd study was undertaken to determine if chemically induced suppression of gut transit time during early infection would enhance infectivity as measured by increased parasite fecundity. Nine rats were injected subcutaneously with an antidiarrheal agent, Loperamide®, known to slow small bowel motility significantly. Another group of 9 control rats was injected with the ethanol-propylene glycol solvent. Ten min after injection, all rats were inoculated per os with 104E. nieschulzi oocysts. The daily number of oocysts discharged/rat was followed from PI days 5–11. Patency began for all rats on PI day 7. The total number of oocysts discharged by the drugged rats as compared with controls was not significantly different. 相似文献
6.
PATRICIA FERNANDES NERES VERÔNICA GOMES DA FONSECA‐GENEVOIS RODRIGO AUGUSTO TORRES MARIANA DA FONSECA CAVALCANTI FRANCISCO JOSÉ VICTOR DE CASTRO NEYVAN RENATO RODRIGUES DA SILVA TANIA TASSINARI RIEGER WILFRIDA DECRAEMER 《Zoological Journal of the Linnean Society》2010,158(1):1-15
A new species of Daptonema is described based upon morphological characters and 18S rRNA sequence. Daptonema matrona sp. nov. was collected in Pina Basin (north‐eastern Brazil). It differs from all other species of the genus by the presence of reduced cephalic setae and straight spicules. These features require an adaptation of the generic diagnosis. Moreover, the females are characterized by intra‐uterine development of the offspring, considered herein as their major autapomorphic feature. Molecular systematic analyses supported Daptonema matrona sp. nov. as a distinct genetic and evolutionary lineage. The data also indicate hypotheses of taxonomic synonymies amongst some related taxa from Xyalidae as well as the paraphyly of Daptonema. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 1–15. 相似文献
7.
In three field experiments, the rhabditid nematode Phasmarhabditis hermaphrodita was applied one or more times at the standard rate (3 × 109 ha?1) or half the standard rate to protect crops from slug damage under experimental conditions. Expt 1 was done in a field planted with the ornamental Polygonatum japonica. The treatments were: infective juveniles of the nematode at the standard field rate, metaldehyde pellets at the recommended field rate, and ioxynil (a herbicide with molluscicidal properties) at 90 mg m?2. The treatments were repeated every 2 wk. Arion ater agg. caused most of the damage to P. japonica. There were no significant differences in damage between treatments during the 3 wk after first application, but plants on plots treated with metaldehyde or nematodes had significantly less damage than plants on untreated plots in the fourth and fifth weeks. Expts 2 and 3 were done on the same site, the first with leaf beet and the second with lettuce. The treatments in these experiments were: nematodes applied to the planted area at the standard field rate 3 days prior to planting, with or without previous application of cow manure; nematodes at half standard rate applied twice, 6 days apart, to the planted area or to the surrounding area; metaldehyde pellets and iron phosphate pellets, both applied at the recommended rate to the planted area immediately after planting. In both experiments, the two chemical molluscicides and nematodes applied once to the planted area at the standard field rate without previous application of cow manure, or twice at half standard rate, were able to reduce slug damage. Nematodes applied after manure did not reduce slug damage. None of the treatments reduced the numbers of slugs contaminating the harvested plants. Slug populations were assessed by means of soil sampling before and after Expts 2 and 3. Only after Expt 3 was there a significant effect of treatment on slug numbers, with significantly fewer in metaldehyde treated plots than in untreated plots. 相似文献
8.
Abstract. In this study, we assessed the ability of mitochondrial genome sequences to recover a test phylogeny of five hymenopteran taxa from which phylogenetic relationships are well accepted. Our analyses indicated that the test phylogeny was well recovered in all nucleotide Bayesian analyses when all the available holometabolan (i.e. outgroup) taxa were included, but only in Bayesian analyses excluding third codon positions when only the hymenopteran representatives and a single outgroup were included. This result suggests that taxon sampling of the outgroup might be as important as taxon sampling of the ingroup when recovering hymenopteran phylogenetic relationships using whole mitochondrial genomes. Parsimony analyses were more sensitive to both taxon sampling and the analytical model than Bayesian analyses, and analyses using the protein dataset did not recover the test phylogeny. In general, mitochondrial genomes did not resolve the position of the Hymenoptera within the Holometabola with confidence, suggesting that an increased taxon sampling, both within the Holometabola and among outgroups, is necessary. 相似文献
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