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Tablés 1 to 3 were omitted from the final printing ofthis article. They are reprinted here. 相似文献
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Mitochondrial DNA products among RAPD profiles are frequent and strongly differentiated between races of Douglas-fir 总被引:5,自引:0,他引:5
Racial differentiation and genetic variability were studied between and within the coastal, north interior, and south interior races of Douglas-fir using RAPD and allozyme markers. Nearly half of all RAPD bands scored (13:45%) were found to be amplified from mitochondrial DNA. They exhibited maternal inheritance among hybrids and back-crosses between the races, and were much more highly differentiated (GST= 0.62 for haplotype frequencies) than were allozymes (GST= 0.26). No evidence of hybridization or introgression was detected where the coastal and interior races come into proximity in central Oregon. 相似文献
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Matrix attachment regions (MARs) enhance transformation frequency and transgene expression in poplar 总被引:13,自引:0,他引:13
We tested the value of a matrix attachment region (MAR) fragment derived from a tobacco gene for increasing the frequency of Agrobacterium-mediated transformation. A binary vector that carried a GUS reporter gene containing an intron and an nptII gene was modified to contain flanking MAR elements within the T-DNA borders. Vectors containing or lacking MARs were then used to transform tobacco, a readily transformabl e poplar clone (Populus tremula × P. alba), and a recalcitrant poplar clone (Populus trichocarpa × P. deltoides). MARs increased GUS gene expression approximately 10-fold in the two hybrid poplar clones and twofold in tobacco one month after cocultivation with Agrobacterium; MARs also increased the frequency of kanamycin-resistant poplar shoots recovered 相似文献
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