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排序方式: 共有3333条查询结果,搜索用时 15 毫秒
151.
Haitham Sayed Gunter Backes Hamed Kayyal Amor Yahyaoui Salvatore Ceccarelli Stefania Grando Ahmad Jahoor Michael Baum 《Euphytica》2004,135(2):225-228
A partial genetic linkage map was constructed on 71 doubled-haploid lines derived from a cross between the barley lines Tadmor
and WI2291 with 181 molecular markers. The segregating population was used to detect markers linked to the gene Mlg conferring resistance to powdery mildew (Erysiphe graminis f. sp. hordei) and to genes for quantitative resistance to scald (Rhynchosporium secalis). The gene Mlg on chromosome 4H was flanked by two AFLP markers at a distance of 2.0 and 2.4 cM, respectively. QTLs for resistance to scald
were detected on chromosomes 2H and 3H. This association of molecular markers with qualitative and quantitative disease resistance
loci represents a valuable starting-point for marker-assisted selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
152.
西瓜枯萎病菌专化型鉴定及防治研究 总被引:8,自引:1,他引:8
1982~1987年间自黑龙江、北京等10个省市采集到60份西瓜病株,分别进行分离和培养鉴定,结果有尖孢镰刀菌、茄病镰刀菌、木贼镰刀菌。致病性试验是将3个镰刀菌分别接种于西瓜品种郑州3号,结果尖孢镰刀菌致病,茄病镰刀菌和木贼镰刀菌不侵染。分别从黄瓜和甜瓜枯萎病株分离出来的尖孢镰刀菌,与西瓜病株分离得的尖孢镰刀菌进行交互接种于西瓜、甜瓜和黄瓜的幼苗上。鉴定的结果是不同的专化型,即尖孢镰刀菌西瓜专化型〔Fusarium oxysporum. f. sp. niveum(E. F. Smith)Snyder et. Hans.〕。在防治上,采用综合防治措施,经过1989~1990年试验,防效达90.91%~92.70%,增产58.95%~64.93%。 相似文献
153.
The inheritance of the Mlk powdery mildew resistance originating from ‘Heine 2174.50’ was analyzed by crossing the Mlk resistant cultivar ‘Ralle’× cv. ‘Amor’ (highly susceptible) and vice versa and by observing the reactions of F1- and F2-plants after inoculation with two different Mlk avirulent powdery mildew isolates. In all cases, a 3 (resistant): I (susceptible) segregation was found in F2. The reactions of the F2plants against the two powdery mildew isolates were identical in each case. Therefore, it is supposed that one dominant resistant gene is responsible for the resistant reactions against these two isolates. These results support the earlier assumption of Heun and Fischbeck (1987b) that the whole Mlk resistance pattern is controlled by a single gene. 相似文献
154.
Summary A genetic study of a range of NORIN 10 based semi-dwarf durum wheats showed that only Gai/Rht 1, located on chromosome 4A, was present. No varieties carrying a second Gai/Rht allele were identified and deliberate attempts to introduce Gai/Rht2 into tetraploid wheats have so far been unsuccessful.In a spaced plant trial of homozygous random F3 lines from two tall x semi-dwarf crosses, the semi-dwarfs has lower ear yields, due mainly to reduced kernel weight, but had higher tiller numbers than the tall genotypes. Although there was no difference in overall plant yield between talls and semi-dwarfs, an analysis of character associations within the semi-dwarf F3's showed positive height-yield and height-kernel weight correlations indicating that selection for tall dwarfs may be a useful breeding strategy in tetraploid wheats. 相似文献
155.
156.
Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield limiting factors in chickpea. The disease causes 10–90% yield losses annually in chickpea. Eight
physiological races of the pathogen (0, 1A, 1B/C, 2, 3, 4, 5 and 6) are reported so far whereas additional races are suspected
from India. The distribution pattern of these races in different parts of the world indicates regional specificity for their
occurrence leading to the perception that F. oxysporum f. sp. ciceris evolved independently in different regions. Pathogen isolates also exhibit differences in disease symptoms. Races 0 and 1B/C
cause yellowing syndrome whereas 1A, 2, 3, 4, 5 and 6 lead to wilting syndrome. Genetics of resistance to two races (1B/C
and 6) is yet to be determined, however, for other races resistance is governed either by monogenes or oligogenes. The individual
genes of oligogenic resistance mechanism delay onset of disease symptoms, a phenomenon called as late wilting. Slow wilting,
i.e., slow development of disease after onset of disease symptoms also occurs in reaction to pathogen; however, its genetics
are not known. Mapping of wilt resistance genes in chickpea is difficult because of minimal polymorphism; however, it has
been facilitated to great extent by the development of sequence tagged microsatellite site (STMS) markers that have revealed
significant interspecific and intraspecific polymorphism. Markers linked to six genes governing resistance to six races (0,
1A, 2, 3, 4 and 5) of the pathogen have been identified and their position on chickpea linkage maps elucidated. These genes
lie in two separate clusters on two different chickpea linkage groups. While the gene for resistance to race 0 is situated
on LG 5 of Winter et al. (Theoretical and Applied Genetics 101:1155–1163, 2000) those governing resistance to races 1A, 2, 3, 4 and 5 spanned a region of 8.2 cM on LG 2. The cluster of five resistance
genes was further subdivided into two sub clusters of 2.8 cM and 2.0 cM, respectively. Map-based cloning can be used to isolate
the six genes mapped so far; however, the region containing these genes needs additional markers to facilitate their isolation.
Cloning of wilt resistance genes is desirable to study their evolution, mechanisms of resistance and their exploitation in
wilt resistance breeding and wilt management. 相似文献
157.
Evaluation of seedling and adult plant resistance to stem rust in European wheat cultivars 总被引:2,自引:0,他引:2
A total of 105 European wheat cultivars were assessed for seedling and adult plant resistance (APR) to stem rust using an
array of Australian isolates of Puccinia graminis f. sp. tritici. Twenty-seven cultivars were susceptible at both seedling and adult plant growth stages. Twelve catalogued seedling stem
rust resistance genes (Sr7b, Sr8a, Sr8b, Sr9b, Sr9g, Sr11, Sr15, Sr17, Sr29, Sr31, Sr36 and Sr38) were detected in the remaining cultivars, and 13 cultivars carried additional seedling resistance genes that could not be
postulated with the isolates used. Low levels of APR to stem rust were found in the cultivars Artaban, Forno, Mec, Mercia,
Pandas and Vlada. Although the genetic identity of this APR was not determined, it was clear that the only designated stem
rust APR gene Sr2 was not present in any of the cultivars tested based on the absence of the linked traits seedling chlorosis and pseudo black
chaff. One of these cultivars, Forno, is believed to carry the leaf rust APR gene Lr34, previously reported to be associated with improved resistance to stem rust. A detailed genetic characterisation of the APRs
in these cultivars will be needed to understand their modes of inheritance and relationships with catalogued stem rust resistance
genes. Such knowledge may help in developing cultivars with effective gene combinations that confer higher levels of protection. 相似文献
158.
159.
S. Rönicke V. Hahn R. Horn I. Grone L. Brahm H. Schnabl W. Friedt 《Plant Breeding》2004,123(2):152-157
Sclerotinia sclerotiorum is considered the most devastating pathogen of sunflower grown in humid environments. In this study, progenies of partial hybrids between Helianthus maximiliani, a wild species that has been shown to be resistant to S. sclerotiorum, and H. annuus were characterized by amplified fragment length polymorphism (AFLP) analysis to identify whether there are introgressions from H. maximiliani into the cultivated sunflower at the molecular level. Wild species‐specific fragments as well as fragments not found in either parent were detected. Progenies tended to cluster together according to the original partial hybrids in the dendrogram by the use of bootstrap procedures. The progenies were studied for their reaction to S. sclerotiorum using artificial inoculation of sunflower heads. Some of the progenies showed a higher level of resistance compared with resistant inbred lines. It was possible to identify two AFLP‐fragments which seem to be linked to Sclerotinia resistance. 相似文献
160.
Small variant wheat populations created by induced mutagenesis (n = 69) or adventitious regeneration (n = 66) were intensively
screened for an altered response (compared to the parent variety ‘Guardian’) to the causal pathogen of powdery mildew in wheat,
Blumeria graminis f. sp. tritici. Intensive field screening following natural infection of replicated plots of wheat lines over two years revealed a total
of 13 mutants exhibiting significantly greater resistance than ‘Guardian’: eight from induced mutagenesis (11.6%) of the M2
population and five from adventitious regeneration (7.6%). Complete resistance was identified in two lines, (one (M66) developed
following induced mutagenesis, and the other (SC240) by adventitious regeneration). The complete resistance in the induced
mutant was stable over two generations and was associated with a high frequency of leaf flecking, and consequently a low grain
yield. Resistance in SC240 proved to be unstable; SC240 exhibited complete resistance to powdery mildew in the SC2 and SC3 generations, but only 20% of the SC4 plants were completely resistant, while the remainder were indistinguishable in mildew response to ‘Guardian’. The mildew
response of all the SC5 generation of SC240 was not significantly different from ‘Guardian’. Yield analysis of the thirteen mutants with increased
resistance in the presence of powdery mildew indicated that eleven exhibitedgrain yields at least as high as that of ‘Guardian’,
while the mutant M19 exhibited a yield significantly higher than that of ‘Guardian’.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献