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1.
Recombinant inbred lines (RILs) of the tef cross Kaye Murri × Fesho were evaluated for nine quantitative traits at three locations
in the central highlands of Ethiopia during the 1998/99 main season in order to estimate the genetic coefficient of variation
(GCV), heritability and genetic advance expected from selection. Highly significant differences were obtained among the RILs
for all traits studied. Grain yield, panicle weight and yield per panicle showed a relatively high GCV (12–16%). A comparatively
high heritability was obtained from days to heading (31%) followed by panicle length (25%) and grain yield (23%). Moderate
amounts of heritability values were obtained for panicle weight and yield per panicle. High genetic advance as percent of
the mean were obtained from grain yield (16%), yield per panicle (12%) and panicle weight (10%) at5% selection intensity,
which indicated the possibility of improving these traits. Several RILs were identified that have exceeded the better yielding
parent at all locations. Grain yield showed a strong positive association (r = 0.26–0.70) with shoot biomass, lodging index,
panicle length, plant height, panicle weight and yield per panicle. Overall, the present results showed a) the availability
of genetic variance for some useful traits in the RILs for exploitation through selection, b) the existence of significant
genotype × location interaction that indicated the need to test inbred populations in more environments, and c)the availability
of superior inbred lines for further breeding work.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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3.
The local ecological knowledge (LEK) and perceptions of grasses were investigated in six semi-arid communal areas in the central Eastern Cape province, South Africa, and compared with field studies and scientific knowledge. Of the total of 21 grasses identified in the field survey, communal farmers had vernacular names only for 11 species. Respondents rated Digitaria eriantha and Pennisetum clandestinum to have the highest (p < 0.05) grazing value. Respondents’ ratings of Eragrostis obtusa and Sporobolus africanus as having similar (moderate) grazing values to Themeda triandra is against the established knowledge. Respondents’ ratings of T. triandra and S. africanus as having higher (p = 0.01) ecological value than the other grasses concur with the scientific knowledge, whereas their nomination of E. obtusa and D. eriantha as providing less ecological benefits than Aristida conjesta disagrees with some ecologists. The study hinted at the complementarity and discrepancies between LEK and scientific knowledge that need ratification. The respondents’ lack of detailed knowledge is suggestive of a gradual eroding of LEK among the local communities that will adversely impact the local people’s ability to implement sustainable rangeland utilisation practice. The current study also recognised farmers’ familiarity as well as training needs that would expound their knowledge and management of grasses. 相似文献
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Tef is a staple cereal of Ethiopia in high demand by consumers. In order to cope up with this high consumer demand, productivity
per unit of land must increase through the development and use of high-yielding varieties. To this effect, the National Tef
Research Project has long been striving towards the development of high yielding varieties through direct selection from germplasm
and concentrating favourable alleles through hybridization and selection, despite the tedious crossing technique. The objective
of this study was to assess the degree of genetic variation in F2 populations of tef as a basis for improving grain yield. F2 populations from 12 crosses and their parents were grown at the Debre Zeit Agricultural Research Center, Ethiopia, and assessment
was made on eight traits on individual plant basis. Eleven of the 12 crosses showed substantial genetic variation for grain
yield and its components, indicating the potential for improvement through selection. Moreover, grain yield, plant weight
and yield related traits showed moderate to high heritability values (17–80%). In all the crosses, tiller number, panicle
weight, yield per panicle and panicle length showed significant (P ≤ 0.05) and positive association with grain yield. Considering the degree of genetic variation and heritability values, emphasis
should be given to selected crosses in an effort to developing high-yielding tef varieties. 相似文献
7.
Kebebew Assefa Seyfu Ketema Hailu Tefera Henry T. Nguyen Abraham Blum Mulu Ayele Guihua Bai Belay Simane Tiruneh Kefyalew 《Euphytica》1999,106(1):87-97
Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated
for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and
Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity
of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean
squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of
variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity
and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes
consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes
the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted
for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm
internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle
emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for
number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed
relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall,
the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement
of the crop through hybridization and selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Summary Twenty-two promising wheat varieties were studied for their plant height, length of filament, size of anther, number of pollen grains/anther and the extent of pollen shed outside the florets. Plant height and length of filament ranged from 54 cm to 136 cm and 4.5 mm to 11.9 mm, respectively. Taller plants showed a tendency to longer filaments. The number of pollen grains/anther varied from 581 to 2153. This character was particularly correlated with plant height. Tall varieties with more pollen grain/anther shed greater quantities of pollen outside the florets. This was due to longer filaments of most of the tall varieties. The size of anther was also positively correlated with pollen grain/anther. 相似文献
9.
Temesgen?AdnewEmail author Seyfu?Ketema Hailu?Tefera H.?Sridhara 《Genetic Resources and Crop Evolution》2005,52(7):891-902
One hundred and forty-four heterogeneous tef germplasm accessions collected from 10 major tef growing areas in Ethiopia were
evaluated for 18 quantitative traits in a simple lattice design, at Holetta and Ginchi, in 2001 main growing season to study
the genetic diversity in tef. The combined analysis of variance revealed the presence of significant variation among germplasm
accessions for all traits studied. Cluster analysis revealed the overlapping of the germplasm accessions from different origin
and the accessions were grouped into eight distinct clusters of 1–78. Generalized distance square confirmed the presence of
significant genetic distance between clusters. In principal component (Prin) analysis, the first four principal components
with latent root values above one accounted for about 80.6% of the variability existing among the germplasm accessions. Prin1
constituted about 55% of the variability mainly from almost equal contribution of 10 quantitative traits, indicating that
most of the traits are equally important in tef diversity. In this study, the regions and altitudes of origin were not found
to have a substantial effect on the genetic diversity in tef germplasm. Diversity within the regions was found to be significant
and, hence, an opportunity for exploitation in tef improvement. 相似文献
10.