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211.
A protocol was developed for direct shoot and plantlet regeneration from in vitro regenerated leaf explants of male Pistacia vera L. cv. ‘Atl?’. Leaves excised from axenic shoot cultures of pistachio were used to induce organogenesis on a Murashige and Skoog (MS) medium with Gamborg vitamins supplemented with combinations of different concentrations of BAP and IAA. The highest adventitious shoot regeneration in 35% of the explants, with the number of shoots ranging from 2 to 3 per explant, occurred in the explants cultured during the establishment phase in the medium with 1 mg l−1 IAA and 2 mg l−1 BAP. For shoot multiplication, the highest number of new microshoot/explants (5.76) was obtained in a culture medium supplemented with 1 mg l−1 BAP, but it was not significantly different from the number obtained at 2 mg l−1 BAP. A high rooting frequency (84%) for microshoots was recorded on a medium supplemented with 2 mg l−1 IBA. In vitro rooted plantlets were transferred to pots filled with a mixture of soil, sand and peat (1:1:1). They were weaned in a growth room and finally moved to a greenhouse. This protocol could be utilized for in vitro clonal propagation of this economically important plant. 相似文献
212.
Three cell lines of groundnut (Arachis hypogaea L), an important oilseed legume, were selected on glyphosate using in-vitro culture techniques. The cell lines isolated through single as well as stepwise selection procedures showed c 20-fold increase in glyphosate tolerance as compared to the unselected control cell line. Studies on the biochemical mechanism of glyphosate tolerance in these cell lines showed a significant increase in the total extractable activity of the target enzyme, 5-enolpyruvyl shikimate-3-phosphate (EPSP) synthase (EC 2.5.1.19), which was further confirmed with immunological data. The over-expressed EPSP synthase activity was, however, subject to inhibition by glyphosate in vitro. Two other key regulated enzymes of the shikimic acid pathway, 3-deoxy-D -arabino heptulosonate 7-phosphate (DAHP) synthase (EC 4.1.2.15) and chorismate mutase (CM) (EC 5.4.99.5) did not show any change in specific activity in the selected cell lines. The enhanced activity of EPSP synthase in the tolerant cell lines was found to be stably inherited in the absence of selection pressure. © 1999 Society of Chemical Industry 相似文献
213.
214.
Pamela J. Hatton Ian Cummins Lindsey J. Price David J. Cole Robert Edwards 《Pest management science》1998,53(3):209-216
Glutathione transferases (GSTs) catalysing the conjugation of 1-chloro-2,4-dinitrobenzene, the chloro-s-triazine herbicide atrazine, the chloroacetanilide herbicides metolachlor and alachlor and the diphenyl ether herbicide fluorodifen have been identified in suspension-cultured cells derived from the grass weed giant foxtail (Setaria faberi Herrm.). In contrast to suspension-cultured cells of maize, where atrazine-conjugating GSTs are lost during de-differentiation, the GSTs active toward this herbicide in S. faberi plants were also expressed in cultures, suggesting that these isoenzymes are subject to different regulation in the crop and weed. As a result, glutathione conjugation was the major route of atrazine metabolism in S. faberi cultures. Activities of these GSTs were maximal three days after sub-culturing when the cells were dividing most actively, when they were determined to be in the order CDNB>alachlor>metolachlor= fluorodifen>atrazine. This indicated that GSTs which are enhanced during cell division can metabolise herbicides. On the basis of activity per mg protein, GST activities in the cultures were between 20 and 60-fold higher than those determined in the foliage of S. faberi seedlings. The GSTs with activity towards CDNB were resolved into three peaks following anion-exchange chromatography at pH 7·8 using Q-Sepharose. Peak 1 GSTs were not retained, while peak 2 and peak 3 were sequentially resolved with an increasing concentration of salt. Peak 1 GSTs showed activity toward metolachlor and atrazine but showed little activity toward fluorodifen. Peak 2 and peak 3 GSTs were active toward atrazine and metolachlor, with peak 3 being particularly associated with activity toward fluorodifen. The GSTs in these peaks were then further purified using S-hexyl-glutathione-agarose affinity chromatography. In each case, the affinity-bound fraction of the GSTs consisted of 28 kDa and 26 kDa polypeptides, suggesting that the GST isoenzymes in S. faberi cultures are composed of related subunits. Our results demonstrate that the GST isoenzymes involved in herbicide metabolism in suspension cultures of a grass weed show a similar level of complexity to that determined in maize cell cultures. © 1998 SCI 相似文献
215.
216.
Soil animal communities of Secondary forest,Platycladus forest andQuercus acutissima forest in Confucian graveyard of Qufu were investigated. 3583 specimens were collected, belonging separately to 5 Phylums,
11 Classes and 23 Orders. Two dominant groups and 9 common groups account for 94.45% of the total numbers. The soil animals
in these three forest habitats differ in composition, ecological distribution and important indices. The dominant groups of
soil animals in the three forests were the same, but other groups differ more greatly. Diversity index (H′) and evenness index
(E) of soil animal in Secondary forest are the highest, and yet dominance index (C) inQuercus acutissima forest is the highest. Most soil animals in each forest habitats congregate to the surface soil layer. Their sorts and individual
numbers are all layer I>II>III. It is very similar for composition of soil animals in the three forests.
Responsible editor: Chai Ruhai 相似文献
217.
D. Lippi M.R. De Paolis E. Di Mattia S. Grego T. Pietrosanti I. Cacciari 《Biology and Fertility of Soils》2000,30(4):276-283
The effect of salinity on growth, starvation-survival and recovery from salt stress of a Rhizobium sp. strain isolated from nodules of Acacia tortilis from a soil of Senegal was studied. Growth parameters of C-limited continuous cultures, grown in the presence and the absence
of 342 mM NaCl, decreased in the saline medium and with increasing dilution rates. The survival capacity of starved cultures
depended on the previous growth conditions: culturability of cells grown with salt was inversely related to growth rate, while
culturability increased with increasing dilution rate for cultures grown without salt. Culturability of the cultures subjected
to the double stress of starvation and salinity was reduced and a high percentage of cells entered the viable but nonculturable
state. All the starved cultures were capable of regrowth when nutrients became available, thus showing that this strain can
withstand long periods of nutrient deprivation in soil while maintaining the capacity for an active metabolism and a potential
infectiousness toward an appropriate host.
Received: 14 December 1998 相似文献
218.
观赏植物试管苗玻璃化现象及防治研究进展 总被引:8,自引:0,他引:8
综述了离体培养中观察到有试管苗玻璃化现象的观赏植物种类,玻璃苗的形态解剖和生理生化特点,影响试管苗玻璃化的因素及克服试管苗玻璃化措施的研究进展。 相似文献
219.
酵母培养物对仔猪生长发育的影响 总被引:3,自引:0,他引:3
采用单因子试验设计研究了仔猪断奶日粮中添加酵母培养物对仔猪断奶后生长发育的影响.试验选用具有相同父本的杜长大仔猪52头,随机分为3组,分别饲喂基础日粮(对照组)、添加0.25%(0.25%组)和0.5%(0.5%组)酵母培养物的日粮,7日龄补饲,自由采食,30日龄断奶,称初生重,7日龄、30日龄、32日龄、39日龄、60日龄体重和各阶段耗料量,记录腹泻次数.结果表明,0.25%组和0.5%组仔猪32日龄体重与断奶前相同或略有增加,对照组显著降低,试验组显著高于对照组(P<0.05);60日龄0.25%组仔猪体重显著高于0.5%组和对照组(P<0.05),0.5%组和对照组之间差异不显著(P>0.05).7~30日龄阶段日增重以0.5%组最高;断奶3日内,试验组的平均日增重均为正值,对照组为负增长,试验组与对照组之间差异极显著(P<0.01);32~39日龄阶段以对照组最高,对照组和0.25%组显著高于0.5%组;39~60日龄阶段0.25%组的日增重显著高于其他两组,其他两组之间差异不显著.同时,添加酵母培养物组仔猪腹泻次数低于对照组.表明在日粮中添加酵母培养物对缓解仔猪断奶后的营养应激和促进断奶后仔猪生长发育和预防仔猪腹泻有一定的作用,酵母培养物在断奶前仔猪饲粮中的适宜添加量为0.5%,断奶后为0.25%. 相似文献
220.
美味猕猴桃原生质体培养及植株再生技术研究 总被引:10,自引:1,他引:10
以美味猕猴桃雄株茎段愈伤组织为材料,分离原生质体,并培养在KM8P附加0.45mol/L葡萄糖和0.05mol/L蔗糖的培养基上,用低熔点琼脂糖包埋,6 ̄7d发生第一次细胞分裂,培养20d的分裂率为11.3%,在未添加新鲜培养液的情况下,原生质体再生的细胞可持续分裂至80d左右,并形成2 ̄3mm大小的愈伤组织,然后采用二步诱导分化法将原生质体来源的愈伤组织诱导分化出绿苗,再诱导生根,形成完整的小植 相似文献