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苹果紧凑型品种和矮化砧木内源激素的变化 总被引:15,自引:0,他引:15
以不同矮化程度的苹果品种、砧木和嫁接植株为试材, 研究了春梢旺长期茎尖和春梢停长期叶片的内源激素变化。结果表明, 与普通型品种相比, 紧凑型品种茎尖和叶片中的赤霉素(GA1+3) 含量显著降低而细胞分裂素(CTKs) 含量显著升高, 紧凑型品种的CTKs/ GA1+3约是普通型品种的4. 78~6. 24 倍。不同矮化程度的砧木间相比, 春梢停长期叶片中, M9 的IAA 含量比平邑甜茶降低了53. 7 %。以M26作中间砧, 显著降低了接穗叶片和基砧新根中的IAA 含量; 但以新红星作中间砧则影响较小。将M26中间砧与紧凑型品种组合, 与乔砧普通型植株相比, 春梢停长期叶片和新根中IAA 含量分别下降了46. 1 %和33. 3 %,CTKs/ GA1+3是其2. 8~3. 6 倍, 其变化幅度大于单一应用矮化砧、紧凑型品种的植株。因此, 紧凑型、矮化砧具有不同的激素调节机制, GA、CTK在紧凑型品种矮化中起重要作用, 而矮砧的矮化可能与IAA 密切相关。 相似文献
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Hana Duranova Monika Martiniakova Radoslav Omelka Birgit Grosskopf Ivana Bobonova Robert Toman 《Acta veterinaria Scandinavica》2014,56(1)
Background
Chronic exposure to cadmium (Cd), even at low concentrations, has an adverse impact on the skeletal system. Histologically, primary and secondary osteons as basic structural elements of compact bone can also be affected by several toxicants leading to changes in bone vascularization and mechanical properties of the bone. The current study was designed to investigate the effect of subchronic peroral exposure to Cd on femoral bone structure including histomorphometry of the osteons in adult male rats.In our study, 20 one-month-old male Wistar rats were randomly divided into two experimental groups. In the first group, young males received a drinking water containing 30 mg of CdCl2/L, for 90 days. Ten one-month-old males without Cd intoxication served as a control group. After 90 days of daily peroral exposure, body weight, femoral weight, femoral length, cortical bone thickness and histological structure of the femora were analysed.Results
We found that subchronic peroral application of Cd had no significant effect on body weight, femoral length and cortical bone thickness in adult rats. On the other hand, femoral weight was significantly increased (P < 0.05) in Cd-intoxicated rats. These rats also displayed different microstructure in the middle part of the compact bone where vascular canals expanded into central area of substantia compacta and supplied primary and secondary osteons. Additionally, a few resorption lacunae which are connected with an early stage of osteoporosis were identified in these individuals. Histomorphometrical evaluations showed that all variables (area, perimeter, maximum and minimum diameter) of the primary osteons’ vascular canals, Haversian canals and secondary osteons were significantly decreased (P < 0.05) in the Cd group rats. This fact points to alterations in bone vascularization.Conclusions
Subchronic peroral exposure to Cd significantly influences femoral weight and histological structure of compact bone in adult male rats. It induces an early stage of osteoporosis and causes reduced bone vascularization. Histomorphometrical changes of primary and secondary osteons allow for the conclusion that the bone mechanical properties could be weakened in the Cd group rats. The current study significantly expands the knowledge on damaging action of Cd on the bone. 相似文献4.
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黄建伟 《农业图书情报学刊》2012,24(4):60-64
介绍密集书库建设的思路和文献入库具体操作流程,密集书库文献管理系统以WEB的方式采用PHP+Sybase方法构建,重点分析图书馆密集书库文献管理系统的设计思路及其功能,给出系统的体系结构及系统实现的关键技术。对SULCMIS系统表B_barcode进行研究和分析,提出了如何在书目检索中与文献管理系统进行挂接。 相似文献
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李跃臣 《农业图书情报学刊》2010,22(3):83-85,93
从我馆密集书库回溯建库工作的实践,提出图书馆应重视回溯建库工作。因为回溯建库工作是图书馆一项重要的基础性工作,是图书馆建设书目体系、完善文献信息检索系统的重要保证,是图书馆提供文献信息的前提和基本条件。图书馆应定期维护书目数据库,确保书目数据著录的完整性和规范,为书目数据共享打下良好的基础。 相似文献