半干旱区四种典型豆科牧草群落生理生态的分异研究

在黄土高原半干旱地区,植物种群生态的改善是植被建设与生态修复的关键。通过人工植被调查,比较了四种豆科牧草的种群生长的生态差异,初步探讨了牧草生产力与种群生态的可能耦合网络机制。结果表明:基于四种豆科牧草种群的土壤水分含量和垂直下降分布规律,发现沙打旺与苜蓿为高生产力型,红豆草与胡枝子为低生产力型,这可能与它们水分利用状况和豆科牧草本身的固氮或氮沉积的氮汇与源转化调节有关。苜蓿植株生物量表现较高,与其多年生庞大根系充分吸收土壤深层水分有关,反映了根冠生长与土壤条件的耦合是导致遗传特性响应差异的重要原因,因此调整植物根冠关系以增强植物的抗旱适应能力理论上是可行的。相关分析发现生产力、根系生物量、土壤环境(水分和层次)为网络耦联相关,特别是90-100cm的土壤空间水分与根冠比成正相关,这可能说明这个层次(根系的浅层集中分布区)为土壤水库与土壤干层相转变的阈值界面。因此从干旱胁迫条件下建立的适应性生存对策上考虑,苜蓿适宜在干旱立地推广应用,不仅具水土保持功效,而且植被生产力高,应为黄土高原生态恢复和生态建设的重要参考物种。     

不同栽植密度对脱毒红薯产量及经济效益的影响

为确定三康8号脱毒红薯的最佳栽植密度并为其推广应用提供依据,采用大田试验方法,研究了不同栽植密度对脱毒红薯产量和经济效益的影响。结果表明:栽植密度为4 600株/667m2时,鲜薯产量高达2 577.9 kg/667m2,产投比高达2.37,是三康8号脱毒红薯的最佳栽植密度。     

冬季凌汛危害成因及防凌管理措施

通过分析冬季凌汛危害的成因,总结出防止凌汛的管理措施,对保证凌汛安全将起到很大的作用。     

Differences in ecological and allelopathic traits among Alternanthera philoxeroides populations

Based on a field investigation and laboratory trials, this study compared the invasive ecology of aquatic and terrestrial alligator weed (Alternanthera philoxeroides G.) ecotypes. The aquatic ecotype showed a stronger eco‐adaptation than the terrestrial ecotype. Alligator weed performed well in wetland and riparian habitats, where it was so competitive that only one‐to‐three other plant types grew successfully in its company. In contrast, it exhibited poor growth in upland fields and parks, where the terrestrial ecotype was dominated by 6–11 other alien plant species. The aquatic ecotype exhibited significantly greater growth inhibition of Microcystis aeruginosa. The ecotypes differed in their pattern of allelopathic inhibition of water blooms. The allelopathic effect of the aquatic ecotype persisted for a period exceeding 20 days, whereas the terrestrial ecotype's allelopathic effect subsided in <5 days. The aquatic ecotype had higher levels of antioxidant compounds, including soluble protein and flavones, and the activity of protective enzymes was also higher, which included superoxidase dismutase, peroxidase and catalase. Alligator weed's unique characteristics derive mainly from its strong allelopathic potential and tolerance of eutrophication in aquatic habitats.     

辽宁动漫游戏产业发展问题及对策研究

动漫产业被誉为21世纪最具发展潜力的朝阳产业之一。近年来,辽宁动漫产业发展迅猛,取得了巨大的成就。但对辽宁动漫产业发展现状进行分析后发现仍存在诸多问题。在世界经济格局重新调整的契机下,实施有效的发展战略是辽宁动漫游戏产业发展的根本保证。     

加强基层野生动物行政管理工作的探讨

概括总结基层野生动物行政管理的重要性,并就如何加强基层野生动物行政管理提出了五个方面的意见。     

Sequencing, Polymorphism and Expression Profile Analysis of Porcine Hexokinase Ⅱ (HK2) Gene

Hexokinase Ⅱ has been demonstrated to play the role of a key enzyme member in the glycolysis reaction. It catalyzes the conversion of glucose to glucose-6-phosphate, thus committing glucose to the glycolytic pathway. In this paper, the partial exons and introns 10, 11, 13 and 14 of the porcine HK2 gene were cloned and sequenced by comparative genomics.Comparative sequencing of three pig breeds revealed ten putative single-nucleotide polymorphisms (SNPs), one of which in intron 10 with differing bases (G981A) is within the restriction site for enzyme Msp Ⅰ. Distribution of Msp Ⅰ -RFLP genotype and allele frequencies among different pig breeds were studied. By association analysis between Msp Ⅰ PCR-RFLP polymorphism (AA, AB, BB genotypes of HK2 gene intron 10) and some meat quality and carcass traits in F2 group,which was constructed by our laboratory, a significant difference of pig average backfat at rump was found between AB and BB genotypes (P ＜ 0 05) in F2 group. In addition, the pattern of expression of HK2 in a variety of tissues in pig was also determined using semi-quantitative RT-PCR. The expression of HK2 mRNA was detected only in pig skeletal muscle.     

新疆野苹果叶形性状变异及其与SSR标记关联分析

以从新疆天山地区新疆野苹果600个无性系中筛选得到的18个优系为研究对象,调查其叶形性状变异,并进行了SSR分子标记分析,探究叶形性状与SSR标记间的相关关系。结果表明,调查的15个叶形性状在无性系间均存在极显著差异;平均变异系数最大的为叶尖角α(达到25.39%),叶形指数L1/L3最小(仅为10.31%);叶片长的重复力最大(达到0.967),叶形指数L1/L3最小(仅为0.495)。以15个叶片性状为依据,可将各无性系完全区分开,并分为3类,各无性系间的遗传距离变化在1.293~7.235间。用均匀分布在17个染色体连锁群上的30对多态性SSR引物对18个无性系进行聚类分析,可将各无性系完全区分开,并可分为4类,各无性系间的遗传距离为0.089~0.689,平均遗传距离为0.433。所有叶形性状聚类结果与所有SSR标记聚类结果不相关。以单一叶形性状聚类结果与经过筛选的部分SSR标记聚类结果进行相关分析,绝大部分达到极显著相关,且大部分引物组合表现为累积效应,表明叶形性状与部分SSR位点具有紧密关联。     

三种生物质炭复合基质对番茄育苗效果的影响

以3种生物质炭(稻壳炭、竹炭、杉木炭)和常用基质(草炭∶蛭石∶珍珠岩=6∶3∶1)为试材,研究了不同配比生物质炭复合基质对番茄育苗效果的影响。结果表明:添加生物质炭能改善普通基质的理化性状,降低其容重和总孔隙度,提高pH值和EC值;不同配比生物质炭复合基质能促进番茄提早出苗,提高其幼苗的株高、茎粗、地上鲜/干重、地下鲜/干重,促进番茄增产;使用生物质炭复合基质培育的番茄幼苗叶绿素含量和根系活力显著降低,但壮苗指数显著提高。该试验选取的3种生物质炭均能替代草炭满足番茄穴盘育苗的基质要求,其中尤以稻壳炭33%+常用基质67%处理最优。