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Association mapping was conducted to explore favorable alleles of the chlorophyll-related non-yellow coloring 1 (NYC1) gene under light and dark using an association panel of 146 maize inbred lines. A total of 14 polymorphic sites were identified to be significantly associated with at least one of the chlorophyll-related traits at the seedling stage. Four single nucleotide polymorphisms (SNPs) (S320, S2951, S3901, and S3355) from the NYC1 gene were respectively strongly associated with chlorophyll b (chlb), the ratio of chlorophyll a to chlorophyll b (chl_ratio), chlorophyll a degradation (chla_deg), and total chlorophyll degradation (total_chl_deg). SNPs S320 (C/A) in exon 1, and S2951 (A/G) in intron 8 was related to chlb, with 6.01 and 8.89% of phenotypic variation under light treatment, respectively. Under dark treatment, SNP S3901 (C/T), located in 3′ untranslated region (3′UTR), was associated with chl_ratio, explaining 7.01% of the observed phenotypic variation, whereas SNP S3355 (C/G) in intron 9 explained 6.48 and 5.18% of phenotypic variations in chla_deg and total_chl_deg, respectively. Taken together, these results indicated that the NYC1 gene plays an important role in chlorophyll content and other related traits, and different sites act on chlorophyll metabolism under different light intensities in maize seedlings. Furthermore, these findings improve our understanding of the genetic basis of chlorophyll metabolism under different light conditions.  相似文献   
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Myanmar indigenous chickens play important roles in food, entertainment, and farm business for the people of Myanmar. In this study, complete mitochondrial D-loop sequences (1232 bp) were analyzed using 176 chickens, including three indigenous breeds, two fighting cock populations, and three indigenous populations to elucidate genetic diversity and accomplish a phylogenetic analysis of Myanmar indigenous chickens. The average haplotype and nucleotide diversities were 0.948 ± 0.009 and 0.00814 ± 0.00024, respectively, exhibiting high genetic diversity of Myanmar indigenous chickens. Sixty-four haplotypes were classified as seven haplogroups, with the majority being haplogroup F. The breeds and populations except Inbinwa had multiple maternal haplogroups, suggesting that they experienced no recent purifying selection and bottleneck events. All breeds and populations examined shared haplogroup F. When 232 sequences belonging to haplogroup F (79 from Myanmar and 153 deposited sequences from other Asian countries/region) were analyzed together, the highest genetic diversity was observed in Myanmar indigenous chickens. Furthermore, Myanmar indigenous chickens and red junglefowls were observed in the center of the star-like median-joining network of 37 F-haplotypes, suggesting that Myanmar is one of the origins of haplogroup F. These findings revealed the unique genetic characteristic of Myanmar indigenous chickens as important genetic resources.  相似文献   
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The genus Amaranthus has gained much attention, particularly for its high economic and nutritional value. It is a genus of taxonomic complexity with many interspecific hybrids. For effective conservation and management of the germplasm collected, the development of a core set of accessions is especially important. A core set of 63 accessions was successfully developed from an entire collection of 634 accessions using the powercore 1.0. Among the tested methods for developing the core set – the advanced M strategy using the modified heuristic method (HCC), randomly chosen collections and stratified random collections – HCC was found to be best, with 100% coverage of alleles and minimum redundancy. Allele frequency distribution of the core set developed with HCC was highly correlated with that of entire collections (r = 0.91). Model‐based structure analysis revealed the presence of three subpopulations and 11 admixtures in the selected core set, which is basically consistent with clustering based on the genetic distance. The results from this study will provide effective information for future germplasm conservation and improvement programmes in Amaranthus.  相似文献   
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A field experiment was carried out to evaluate the effect of two whole-crop rice (Oryza sativa L.) cultivars, TULT and Takanari, on methane (CH4) emission in a paddy field fertilized with biogas slurry (BS) at rates of 0 (NF), 100 (BS100) and 300 (BS300) kg nitrogen (N) ha?1, in comparison with chemical fertilizer CF100 (100 kg N ha?1). Takanari produced significantly higher biomass (< 0.001) than TULT and showed significantly (< 0.01) lower CH4 emission than TULT. BS applications caused higher CH4 emission (52 ± 27 and 80 ± 19 g m?2 in BS100 and BS300, respectively) than did CF100 (42 ± 18 g m?2) and NF (28 ± 10 g m?2) in TULT. In contrast, there was no significant difference in CH4 emission in Takanari among the treatments (26 ± 2, 26 ± 2, 32 ± 4, 29 ± 8 g m?2 in NF, CF100, BS100 and BS300, respectively). Methane oxidizing bacteria (MOB) showed significantly (< 0.05) higher populations in Takanari than in TULT at harvest, which might be due to the higher root biomass (10.3 ± 2.2 g hill?1) in Takanari than in TULT (8.9 ± 1.8 g hill?1). MOB was significantly correlated with tiller number (R2 = 0.176*) and plant biomass (R2 = 0.242*). BS application showed higher copper (Cu) uptake in Takanari while it was not high in TULT. In contrast, it showed no difference in zinc (Zn) uptake in both varieties. Uptake of Cu was not different between the two varieties, while uptake of Zn in the grain was higher in TULT than in Takanari. The present study suggests that CH4 emission deriving from BS application in paddy field can be mitigated by selecting an appropriate cultivar, like Takanari. However, care should be taken for heavy metal uptake in selecting cultivars.  相似文献   
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This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20‐min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.  相似文献   
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