栎属4个树种秋冬叶色与生理变化的关系

为了研究栎类树种秋冬转色期叶色变化的生理机制,以栎属4个树种——鲜红栎(Quercus coccinea)、纳塔栎(Quercus nuttallii)、沈氏栎(Quercus shumardi)、针栎(Quercus palustris)为试材,测定其秋冬转色期叶绿素、类胡萝卜素、花色素苷3种色素和可溶性糖、可溶性蛋白质含量变化。结果表明:叶绿素a、叶绿素b、总叶绿素含量均呈先快后慢的下降趋势;类胡萝卜素含量鲜红栎和沈氏栎呈现下降-上升-下降的趋势,其他2个树种呈平缓下降的趋势;花色素苷含量呈波动上升趋势;叶绿素a与叶绿素b的比值变化趋势前中期较为平缓,后期迅速下降;鲜红栎的可溶性糖含量为单峰曲线,其他3个树种呈双峰曲线,与花色素苷相关性不显著;蛋白质含量与花色素苷含量呈正相关。     

不同树龄桐花树根系生长和根系活力的比较研究

为探索树龄对根系生长和根系活力的影响,以1年龄和2年龄桐花树为试验材料,对不同树龄桐花树(Aegiceras corniculatum)根系生长和根系活力进行比较研究。结果表明：处理360天后,2种树龄的桐花树年生物量均有增加,2年龄单株生物量是1年龄的2.45倍。根生物量在单株生物量中所占的比重,随着树龄的递增呈减小趋势。1年龄根数、根长和根粗的年增量均显著大于2年龄的;两者的根系含水量均呈先升后降的趋势,2年龄根系活力较1年龄的相对稳定些。试验表明,不同树龄的桐花树根系生长和根系活力有显著差异。     

贵州野生毛葡萄种子萌发生理特性研究

以贵州野生毛葡萄种子为试材,对种子萌发过程中的吸水量和细胞膜透性、粗脂肪含量、可溶性糖含量和淀粉含量等指标变化进行了研究。结果表明：毛葡萄种子在萌发过程中,吸水量变化呈“快-慢-快”趋势,膜透性、粗脂肪含量和淀粉含量逐渐下降;而可溶性糖含量的变化则表现出先上升后下降的趋势。     

基于ZigBee的工厂化水产养殖溶解氧在线监控系统设计的研究

为了采用分散控制方式对工厂化水产养殖溶解氧进行监控,提出了基于ZigBee的溶解氧在线监控系统。系统采用集散控制模式,分为终端节点、路由节点和网关节点以及监控中心4个层次。终端节点采集养殖池中溶氧量,然后通过路由节点汇聚到网关节点,并根据溶氧量对与之连接的增氧机进行控制。网关节点将所有终端节点数据传输给监控中心,并接收监控中心的控制指令,进而通过各终端节点控制增氧机。同时,监控中心对数据进行存储、统计和分析,并产生控制指令。ZigBee节点采用CC2430作为核心芯片,使用ZigBee2006协议栈实现无线网络节点之间的通信。结果表明：该系统稳定性较好,部署灵活、容易扩展,满足了工厂化水产养殖的要求。实现了对溶解氧的在线实时监测及对增氧机的有效控制,降低了养殖成本。     

电解铜离子浓度对循环水养殖系统杀菌效果的影响

【研究目的】本文旨在研究循环水养殖系统中铜离子浓度对系统净化效能的影响;【方法】通过在循环水养殖系统中利用铜离子发生器添加铜离子,监测水质和斑马鱼健康状况,评价杀菌效果;【结果】铜离子发生器的铜离子增加速度R2=0.9942,稳定性较好。在24 h时,斑马鱼在铜离子浓度达到0.76 mg/L时,出现死亡情况;另外在同一浓度范围内,温度越低,斑马鱼对铜离子的耐受度越高,同一温度下,铜离子浓度越大,斑马鱼死亡速度越快。在安全浓度范围内（Cu2 +为0~0.23 mg/L）,(26±2)℃为事宜养殖温度,并且0.14~0.226 mg/L范围内的铜离子浓度能有效地抑制细菌生长。最后本研究利用斑马鱼进行20天的养殖验证试验,随着铜离子浓度增加,硝酸盐、亚硝酸盐、总氨氮的变化趋势较为一致;【结论】铜离子浓度在0.1~0.2 mg/L之间,养殖温度(26±2)℃时,硝酸盐、亚硝酸盐、总氨氮、细菌总数处于平稳状态,有利于斑马鱼生长。     

Field Performance of Androgenetic Doubled Haploid Spring Wheat Lines in Comparison with Lines Selected by the Pedigree System

A total of 316 doubled haploid lines (DH) of spring wheat were compared with 621 lines selected in a pedigree system (PS) under field conditions in a breeding nursery. The lines originated from 21 crosses and the samples tested represent mean values for variables comprising the main breeding goals such as disease resistance, baking quality, and agronomic traits. In general, the DH lines were later in days to heading and shorter than PS lines of different homozygosity levels. Except for leaf rust (Puccinia recondite), the DHs were more resistant to the artificially infected diseases such as powdery mildew (Erysiphe graminis), stripe rust (Puccinia striiformis), and septoria nodorum blotch (Septoria nodorum). These differences, which were relatively small for practical selection purposes, were probably due to easier and more precise disease assessment of the homozygous DH lines. For quality characters, the DHs had a higher protein level, while the rest of the parameters were similar for both origins. The data analyzed suggest so far that androgentic doubled haploids in spring wheat are very similar to lines selected in a pedigree system in respect to all the agronomic characters tested. However, the DH lines were produced in a much shorter period of time. It is suggested that androgenetic doubled haploids be produced from F₁ hybrids and that the well-established bulk method should continue to allow selection bulk method should continue to allow selection for rare recombinants as soon as homozygosity is reached.