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51.
激动素在黄瓜子叶器官分化中的作用 总被引:4,自引:0,他引:4
采用在培养初期分阶段供应激动素 (KT)的方法 ,研究了其对黄瓜子叶器官分化的影响 ,并对全程供应和不供应KT下子叶中内源多胺和内源激素的变化进行了动态测定。结果表明 :1)供应KT使不定根分化率下降 ,不影响营养芽的分化 ,而对于花芽分化则是必需的。2 )供应KT使多胺中腐胺 (Put)含量变化最为显著 ,在培养第 2、 6d出现峰值 ,在第 4d呈低谷 ,对照则在第 4d出现峰值。 3)供应KT使培养 2d的子叶中吲哚乙酸 (IAA)和脱落酸(ABA)含量显著降低 ,4d时IAA含量显著升高。据上结果 ,就这些生理变化和花芽分化之间是否存在相关进行了充分讨论。 相似文献
52.
Over 3 consecutive years (1992–1994), a collection of cucumber haploids was obtained from three different lines and one hybrid.
Attempts were made to maintain and store a subcollection of these haploids for 3 years. Cucumber haploids appeared to be stable
when cultured in vitro. There were no instances of spontaneous doubling and only one morphologically changed plant. During
the first year of storage, between 30% and 80% the clones were lost, due to disturbances in plant development, increased levels
of endogenous bacteria, and physiological changes resulting in continuous flowering. After 2 years of storage haploids showed
reduced vigour. Therefore, plants were regenerated directly from primordial leaf microexplants. Haploid plants were obtained
from nearly all of the previous haploid plants. The rejuvenated haploids possessed the same ploidy level and morphological
traits as the old collection. The only new characteristic was faster vegetative growth.
Received: 17 March 1998 / Revision received: 14 April 1999 / Accepted: 10 May 1999 相似文献
53.
J. P. T. Valkonen K. N. Watanabe 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(6):996-1005
Cucumber mosaic virus (CMV) is a commonly occurring plant virus that causes severe damage in many crops, including the diploid
crop species tomato and pepper (Lycopersicon spp. and Capsicum spp., respectively) of the family Solanaceae, but it is neither common nor economically important in cultivated potatoes
(Solanum tuberosum; Solanaceae). Resistance to CMV was examined in two diploid (2n=2x=24), highly heterozygous potato populations (Solanum spp.; Solanaceae) consisting of 76 and 126 progeny. Resistance to long-distance transport of CMV controlled by one locus
with a major effect and functional at a low temperature (18°C) but overcome at a high temperature (28°C) was identified in
one population. In the other population, resistance was controlled by two loci with major effects. In both populations, additional
genes with minor effects were probably also involved. Induced resistance to CMV, associated with autonomously developing cell
death lesions (Anl) previously not known in potato, was expressed in one parental line. The mechanisms of resistance to CMV
may be associated with an inherent or developmental lack of host factors required for compatible CMV-host interactions in
viral long distance transport and/or inability of CMV to efficiently suppress the host gene silencing mechanism in potatoes.
Polyploidy (gene dose) and high heterozygosity (multiple homologous genes) of potato cultivars may be significant in conferring
the durable resistance to CMV. These data provide explanations why CMV is not common and economically important in cultivated
potatoes, even though CMV commonly occurs in other crops, weeds and wild plants in potato production areas.
Received: 11 February 1999 / Accepted: 25 March 1999 相似文献
54.
Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation).
Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS-95) for 1–2 days, frozen and subsequently
examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency
of peg formation in space-grown seedlings was found to be nearly identical to that of clinostat-grown seedlings and to differ
from that of seedlings germinated under normal gravity only in a minority of cases; ˜6% of the seedlings formed two pegs and
nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation
was found to be less pronounced for space-grown seedlings, compared to clinostat-grown seedlings, indicating a greater degree
of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook,
the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even
in microgravity environments. Peg morphologies were altered in space-grown samples, with the pegs having a blunt appearance
and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards.
These phenotypes were not observed in clinostat or ground-grown seedlings.
Received 12 October 1999/ Accepted in revised form 18 October 1999 相似文献
55.
黄瓜花叶病毒(CMV)运动蛋白基因介导的抗病性 总被引:4,自引:0,他引:4
利用Fny_CMV株系RNA3cDNA克隆,构建了含有全长和编码区缺失501个核苷酸的运动蛋白(MP)基因植物表达载体pBMPR和pBMPK。在土壤农杆菌(Agrobacteriumtumefaciens(SmithetTownsend)Conn)LBA4404介导下转化烟草(NicotianatabacumL.)品种“NC89”,分别经Southernbloting、RT_PCR或Westernbloting分析,外源基因已整合到再生植株中并得到表达。抗病性分析表明,含有缺失型MP基因的R0代转基因植株抗性较好,接种50d后,10株转化植株中仍有5株不表现症状。在自然发病条件下,这5个含有缺失型MP基因转基因株系在R1代都表现了一定的抗病性。抗性主要表现为症状出现推迟,严重度减轻。利用PCR筛选、种子卡那霉素抗性试验和温室抗病性测定等方法,初步认为R2代转基因烟草K_6_5株系为转基因抗病纯合系。而含有全长MP基因的R0代转化植株,前期没有表现明显的抗病性,但在接种40d后部分发病植株有恢复健康的趋势。 相似文献
56.
A growth analysis was made of ultraviolet-B (UV-B)-sensitive (Poinsett) and insensitive (Ashley) cultivars of Cucuumis satives L. grown in growth chambers at 600 μmol m−2 s−1 of photosynthetic photon flux (PPF) provided by red- and far-red-deficient metal halide (MH) or blue- and UV-A-deficient high pressure sodium/deluxe f HPS/DX) lamps. Plants were irradiated 6 h daiiy with 0.2 f-UV-B) or 18.2 C+UV-B) kJ m−2 day−1 of biologically effective UV-B for 8 or 15 days from time of seeding. In general, plants given supplemental UV-B for 15 days showed lower leaf area ratio (LARs, and higher specific leaf mass (SLM) mean relative growth rate (MRGR) and net assimilation rate (NAR) than that of control plants, but they showed no difference in leaf mass ratio (LMR), Plants grown under HPS/DX lamps vs MH lamps showed higher SLM and NAR. lower LAR and LMR. hut no difference in MRGR. LMR was the only growth parameter affected by cultivar: at 15 days, it was slightly greater in Poinsett than in Ashley. There were no interactive effects of UV-B. PPF source or cultivar on any of the growth parameters determined, indicating that the choice of either HPS/DX or MH lamps should not affect growth response to UV-B radiation. This was true even though leaves of UV-B-irradiated plants grown under HPS/DX lamps have been shown to have greater chlorosis than those grown under MH lamps. 相似文献
57.
In nonparthenocarpic cucumber, analysis of the interaction between season and female receptivity demonstrated two different modes of fruit development and seed set. Spring climatic conditions induced significantly longer ovaries at anthesis with an autonomous fruit set as in natural parthenocarpy. Autumn climatic conditions induced smaller ovaries with fruit set influenced by the pollination stage of the female flower. These differences involve, during fruit development, a regulation of the empty seed number especially at both ends of female receptivity period. Indeed, seasons have no effect on ovule receptivity and fertility measured by full seed number. It is supposed that priority is given to seeds with an embryo in the competition for limited maternal resources in spring as well as in autumn. In spring, the use of irradiated pollen during the whole female receptivity period did not modify the seed set profile. Moreover, a cytological study of 6-day-old ovules pollinated by irradiated pollen has revealed a similar precocious embryogenesis compared to the control. In cucumber, pollination with irradiated pollen involves stenospermocarpy rather than induced parthenocarpy. However, we have not been able to determine whether the early abortive embryogenesis induced by irradiated pollen is gynogenetic or abnormal zygotic. 相似文献
58.
BA(benzyl adenine)专一性地促进离体黄瓜子叶的扩张。为了研究 BA 的作用机理,我们采用间接 EIISA 和 HPLC 的方法测定了子叶扩张过程中内源玉米素(Z)和玉米素核苷(ZR)含量的变化。离体黄瓜(Cucumis sativus,津研4号)子叶用10mg/l 的 BA 培养,72小时之后,处理子叶鲜重的增加比对照高70%。Z+ZR 在 BA 处理的子叶中有大量的积累。结果表明 BA 可能诱发了黄瓜子叶中的细胞分裂素生物合成和代谢的某些基因。 相似文献
59.
60.
Study of multiplication of cucumber mosaic virus in susceptible and resistant Capsicum annuuum lines
R. NONO-WOMDIM K. GEBRE-SELASSIE A. PALLOIX E. POCHARD G. MARCHOUX 《The Annals of applied biology》1993,122(1):49-56
A previous survey on pepper lines (Capsicum annuum L.) indicated that a susceptible cultivar, Yolo Wonder, reacted to cucumber mosaic virus (CMV) by producing a systemic yellow mosaic. By contrast, CMV caused no symptoms on lines Perennial and Vania. The virus is recoverable from the uninoculated leaves of Perennial, while in Vania CMV is restricted to the inoculated leaves. To interpret these phenomena, a comparative study on CMV multiplication rates, yield, specific infectivity and relative proportion of RNAs was made in the inoculated leaves of the three pepper varieties. The rate of CMV multiplication, as estimated by the double antibody sandwich form of enzyme-linked immu-nosorbent assay, was lower in Perennial than in Vania or Yolo Wonder. The yield of virus purified from Perennial was very low when compared with Vania or Yolo Wonder. The specific infectivity of the virus extracted from Perennial was less than that from Vania or Yolo Wonder. These results suggest that Perennial is resistant to CMV multiplication, while restriction of the virus in inoculated leaves of Vania is not due to the inhibition of the virus replication. However, polyacrylamide gel electrophoresis revealed that the RNA profiles of CMV purified from the three pepper lines were similar. 相似文献