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991.
The characterization of plant genetic resources is the first step towards improving their use. The Spanish Plant Genetic Resources
Centre, which belongs to the National Institute for Agricultural and Food Technology Research (CRF-INIA), conserves accessions
of wild underground vetches collected in Spain. In the present work, 26 underground vetch accessions were characterized in
terms of their seed storage proteins (separated by SDS-PAGE) as a means of assessing the genetic variation of these plants
and their agronomic value. Vicia sativa cv. Vereda was used as control. A total of 54 bands were detected, of which 49 were polymorphic. Fifty eight different electrophoretic
patterns were observed in total. Protein bands were scored in terms of their presence (1) or absence (0) for all the seeds
studied, and two matrices constructed, one with all the bands present in each accession, the other with the different patterns
for each accession. Dendrograms based on the Jaccard similarity index and the UPGMA clustering method were produced from these
matrices, and the degree of genetic variation between and within accessions was calculated. The groups obtained were compared
with the chromosome number for each accession. The results reflect the great diversity of underground vetch seed storage proteins.
The aerial and underground seeds of 16 accessions were then analysed separately. In some cases, the aerial and underground
flowers of the same plant produced different proteins. 相似文献
992.
Alex Beharav Roi Ben-David Ivana Doležalová Aleš Lebeda 《Genetic Resources and Crop Evolution》2010,57(5):679-686
The wild lettuce, Lactuca aculeata Boiss. et Ky., is closely related and fully interfertile with cultivated lettuce, Lactuca sativa L. Altogether, 155 accessions of this wild species, which is rare conserved within the world’s germplasm collections, were
collected from 12 localities throughout northeastern Israel. Ten of these localities represent different sites across the
Golan Heights, while two, high-density populations were suprisingly found at the Hula Plain (first report of this species
in this region). Lactuca aculeata was recorded at various elevations (222–968 m a.s.l.) and habitats. The taxonomic status of 30 L. aculeata accessions was morphologically validated during ex situ seed regeneration of 31 random accessions representing all 12 localities. Characterization of 12 traits showed that the Israeli
populations of L. aculeata do not exhibit broad morphological variability, but more great levels of variation were obtained for developmental traits.
Relatively little variability was observed in the morphology of cauline leaves or in the distribution of anthocyanin pigmentation
in bracteae. In two cases, L. aculeata plants lacked trichomes in the inflorescence, a typical feature in the majority of plants. These unique collections of wild
lettuce may carry novel sources of genetic variation for a wide range of traits and, thus, should be of interest for careful
evaluation and exploitation in lettuce breeding. 相似文献
993.
994.
L. Riahi N. Zoghlami K. El-Heit V. Laucou L. Le Cunff J. M. Boursiquot T. Lacombe A. Mliki A. Ghorbel P. This 《Genetic Resources and Crop Evolution》2010,57(2):255-272
Three gene pools representative of Vitis vinifera L. subsp. vinifera (=subsp. sativa Beger) growing in the Maghreb regions (North Africa) from Tunisia (44), Algeria (31) and Morocco (18) and 16 wild grape accessions
(Vitis vinifera L. subsp. sylvestris (Gmelin) Beger) from Tunisia were analysed for genetic diversity and differentiation at twenty nuclear microsatellites markers
distributed throughout the 19 grape chromosomes. 203 alleles with a mean number of 10.15 alleles per locus were observed in
a total of 109 accessions. Genetic diversities were high in all populations with values ranging from 0.6775 (Moroccan cultivars)
to 0.7254 (Tunisian cultivars). F
st pairwise values between cultivated grapevine populations were low but found to be significantly different from zero. High
F
st pairwise values were shown between wild and cultivated compartments. Two parent offspring relationships, two synonyms and
two clones of the same cultivar were detected. The rate of gene flow caused by vegetative dissemination of cultivated grapevine
plants was not sufficient to genetically homogenise the pools of cultivars grown in different regions. The Neighbour Joining
cluster analysis showed a clear separation according to geographical origins for the cultivated grapevines gene pools and
revealed a high dissimilarity between cultivated and wild grapevine. However, three cultivars (Plant d’Ouchtata 1, Plant de
Tabarka 3 and Plant d’Ouchtata 3) are very close to wild accessions and may result from a hybridisation between cultivated
and wild accessions. The high level of differentiation between cultivated and wild accessions indicates that the cultivated
accessions do not derive directly from local wild populations but could mostly correspond to imported materials introduced
from others regions during historical times or derived from crossing between them. 相似文献
995.
Ilknur Solmaz Nebahat Sari Yildiz Aka-Kacar N. Yesim Yalcin-Mendi 《Genetic Resources and Crop Evolution》2010,57(5):763-771
Genetic diversity of the Turkish watermelon genetic resources was evaluated using different Citrullus species, wild relatives, foreign landraces, open pollinated (OP) and commercial hybrid cultivars by RAPD markers. The germplasm
was consisted of 303 accessions collected from various geographical regions. Twenty-two of 35 RAPD primers generated a total
of 241 reproducible bands, 146 (60.6%) of which were polymorphic. Based on the RAPD data the genetic similarity coefficients
were calculated and the dendrogram was constructed using UPGMA (Unweighted pair-group method with arithmetic average). Cluster
analysis of the 303 accessions employing RAPD data resulted in a multi-branched dendrogram indicating that most of the Turkish
accessions belonging to var. lanatus of Citrullus lanatus (Thunb.) Matsum et Nakai were grouped together. Accessions of different Citrullus species and Praecitrullus fistulosus (Stocks) Pangalo formed distant clusters from C. lanatus var. lanatus. Among 303 accessions, a subset of 56 accessions was selected representing different groups and a second dendrogram was constructed.
The genetic similarity coefficients (GS) within the Turkish accessions were ranged from 0.76 to 1.00 with 0.94 average indicating
that they are closely related. Taken together, our results indicated that low genetic variability exist among the watermelon
genetic resources collected from Turkey contrary to their remarkable phenotypic diversity. 相似文献
996.
Crop wild relatives are invaluable sources of novel genes for crop improvement and adaptation to changing environments. We
assessed phylogenetic relationships among 29 Linum accessions representing 16 species, including cultivated flax and its progenitor pale flax, based on four non-coding regions
of chloroplast DNA sequences. We obtained a cpDNA network showing that these 16 Linum species are appropriately connected based on previously defined taxonomic sections; these connections reflect the same evolutionary
pathways as determined from earlier morphological and cytological data. These relationships also support an earlier hypothesis
that cultivated flax is probably descended from a single domestication of pale flax plants, apparently for oil usage. The
detailed species network not only is significant for understanding evolutionary relationships of Linum species, but also useful for classifying exotic gene pools of cultivated flax as a part of the ongoing exploration of new
genetic diversity for flax improvement. 相似文献
997.
D. Arias J. Peñaloza-Ramírez O. Dorado P. Cuevas-Reyes Esaú Leyva Ana Luisa Albarrán-Lara G. Rangel-Altamirano 《Genetic Resources and Crop Evolution》2010,57(8):1227-1238
Jacaratia mexicana A. DC. (Caricaceae) is a tropical tree distributed throughout Mexico and Mesoamerica. Some evidence in Mexico indicates the
presence of an incipient domestication process in this species. Phylogeographical analyses can potentially determine contemporary
patterns of gene flow, isolation between population lineages, as well as historical processes such as population bottlenecks
or expansions on their geographical areas. In this study we reconstruct the phylogeographical patterns in populations of J. mexicana A. DC., in order to find differences between genetic variation among wild and cultivated populations utilizing chloroplast
DNA and nuclear DNA sequences. We generate a Bayesian phylogenetic tree, to estimate the divergence time between clades using
calibrated mutation rates. We also infer the demographic history of these populations using neutrality tests among wild and
cultivated accessions. We identified higher levels of haplotype and nucleotide diversity for the cpDNA and ITS types in wild
populations than in domesticated populations. These results indicate a reduction of genetic diversity derived from human selection
on domestication traits. Neutrality test suggests population expansion detected by the significant negative values of Fu’s
Fs in the cultivated populations of this specie. These process results in an excess of rare polymorphism with the fixation
of certain advantageous mutation throughout time, this implication are in accordance with the role of the strong selection
in the fruit traits of J. mexicana. The dated phylogeny constructed with BEAST program indicated a dispersion pattern for the J. mexicana ancestors across the South Pacific and South Eastern populations during the late Pliocene. Posterior dispersion and divergence
in the clades from Central Mexico and North Pacific are in agreement with the episodes of mountain-building in different regions
of Mexico. 相似文献
998.
Dong Yibo Pei Xinwu Yuan Qianhua Wu Hongjin Wang Xujing Jia Shirong Peng Yufa 《Genetic Resources and Crop Evolution》2010,57(6):915-926
In this study, ecological, morphological and genetic diversity in 11 surviving populations of Oryza rufipogon Griff. from Hainan Island, China were investigated. These data served to provide much needed data in support of conservation strategies. The results divided O. rufipogon into six ecotypes. The cluster analysis based on 19 morphological features showed clear differentiation among populations or within populations. The cluster analysis based on SSR also revealed similar results. The ecological, morphological and genetic diversity observed in O. rufipogon resulted in the following conservation recommendations: (1) the four currently protected O. rufipogon localities should be maintained, due to the different ecological communities represented at these sites; (2) some populations, such as HL (Hele county, Hainan Island), should be protected, but some populations, such as FC (Fucheng county, Hainan Island) and DL (Dalu county, Hainan Island), might not be protected. (3) An isolation zone should be established to avoid possible introgression between O. sativa L. and O. rufipogon; and human activities that impact O. rufipogon should be reduced or eliminated. 相似文献
999.
[目的] 研究福建省生态系统碳储量及其对土地利用变化的响应,为生态系统保护提供参考。[方法] 基于土地利用数据和碳密度数据,运用InVEST模型模拟福建省1980,2000,2020年碳储量;利用冷热点分布、转移图谱和矩阵分析碳储量和土地利用的时空特征;最后分析碳储量对土地利用变化的响应。[结果] ①福建省碳储量整体均较高,82.5%以上区域的碳储量为中等以上(>3 000 t),主要分布在山地丘陵地区,也是高碳储量的热点集中区;高(热点)低(冷点)碳储量集中区转移较少;1980—2020年总碳储量波动略升高,2000—2020年不同碳储量等级彼此之间转移相对较多。②福建省土地利用/覆被以林地为主(61.4%~62.9%),其次是耕地(16.9%~18.3%)和草地(15.2%~17.2%);土地利用/覆被变化在1980—2000年较稳定,在2000—2020年较剧烈。③林地、草地和耕地的总碳储量较高,水域、建设用地和未利用地总碳储量较少;耕地总碳储量减少,建设用地总碳储量增加,林地和草地有增加也有减少;由土地利用/覆被变化导致的总碳储量转出和转入最多均为林地,其次是草地和耕地;总碳储量净转移为负的是林地,其他为正,林地转移引起的碳亏损最多。[结论] 耕地、林地和草地是福建省的主要土地利用类型,它们贡献了较高碳储量,并相互转移引起了碳储量变化。 相似文献
1000.