松嫩平原羊草草地土壤-植物间铁的动态研究

羊草草地土壤-植物间营养元素Fe的动态研究结果表明,土壤中全铁和有效铁含量均较低,羊草中Fe含量比较丰富．在生长季各时期,全铁和有效铁含量在土壤剖面分布上从上向下呈下降趋势,有效铁与有机质含量呈显著正相关,而与pH值呈显著负相关．全铁各月平均含量变化在生长季呈“V”型曲线,7月含量最低;有效铁平均含量从5～8月与全铁相似,8月后则逐渐减少．羊草各器官及枯落物Fe含量有很大变化,总的趋势是根>根茎>叶>枯落物>茎;羊草叶、茎的Fe含量在生长季中为波动型下降曲线,根茎、根及枯落物的Fe含量在生长季中为“V”型曲线．A层土壤富集有效铁的能力稍强．土壤中Fe活性平均为0．640％。从5月至8月逐渐升高,8月后逐渐下降,10月份最低．地下部的Fe向地上部的转移强度为5～7月下降,8月升高,随后又下降．地上部Fe向枯落物的转移强度平均为105．0％,与地下部Fe向地上部转移强度呈显著负相关。     

Pollen dispersion, pollen viability and pistil receptivity in Leymus chinensis

BACKGROUND AND AIMS: Leymus chinensis is an economically and ecologically important grass that is widely distributed across eastern areas of the Eurasian steppe. A major problem facing its propagation by man is its low sexual reproductivity. The causes of low fecundity are uncertain, largely because many aspects of the reproductive biology of this species remained unknown or incomplete. This study aims to address some of these issues. METHODS: Pollen dispersion, pollen viability, pollen longevity and pistil receptivity were studied in a representative, natural population of L. chinensis growing in Inner Mongolia. KEY RESULTS: Flowering of L. chinensis occurred at the end of June and lasted for 5 d. Pollination peaked between 1600 h and 1700 h, and about 56.1 % of the total pollen grains were released at this time. Pollen density was highest towards the middle of flowering spikes and lowest at the bottom over the 5 d measurement period. Pollen viability (62.4 %) assessed using TTC was more accurate than using IKI (85.6 %); 50 % of pollen arriving on stigmas germinated. Pollen remained viable for only 3 h and the pollen : ovule ratio was 79 333 : 1. Pistil receptivity lasted for only 3 h and, overall, 86.7 % of pistils were pollinated. Within the spike, the relative fecundity of different positions was middle > lower > upper throughout the period of pollination; daily variation of fecundity was similar to that of the pollen flow. The spikes that opened on the day of highest pollen density exhibited the highest fecundity (36.0 %). No seeds were produced by self-pollination. CONCLUSIONS: The data suggest that low pollen viability, short pollen longevity and short pistil receptivity all appear to contribute to the low seed production typical of this important forage crop.     

斑块生境中食果鸟类对南方红豆杉种子的取食和传播

生境斑块化对食果鸟类的移动行为产生影响,进而影响其对植物种子的传播格局和效率。南方红豆杉(Taxus chinensis var.mairei)是我国一级保护植物,在南方山区多因人为干扰而呈斑块状分布。2011年,2012年10月底到12月中,以分布于福建梅花山国家级自然保护区红豆杉生态园中南方红豆杉种群为对象,研究斑块生境中鸟类对南方红豆杉种子的取食和传播行为,并评估专性鸟类和泛性鸟类的传播效率。结果发现:南方红豆杉源斑块共吸引22种食果鸟类取食红豆杉种子,并与13种鸟类形成了种子传播关系。不同年间,黑短脚鹎(Hypsipetes leucocephalus)都是植物的主要传播鸟类,而其他鸟类传播者种类具有一定的年间变化。生境斑块化导致专性鸟类黑短脚鹎和泛性鸟类红嘴蓝鹊(Urocissa erythrorhyncha)种子传播效率差异。与红嘴蓝鹊相比,黑短脚鹎飞行的平均距离较短((16.3±11.0)m,Mean±SD,n=125),传播距离相对较近;且它们取食后偏好在源斑块中活动,喜栖息在同种成树、甜楮(Castanopsis eyrei)及其他阔叶树等栖树上。红嘴蓝鹊取食后常在斑块间移动,常停歇在同种成树和毛竹(Phyllostachys heterocycla)上,传播距离相对较远((24.9±20.0)m,Mean±SD,n=95)。空间一致性结果表明,黑短脚鹎移动距离对幼苗更新距离的空间一致性程度高;而红嘴蓝鹊偏好生境与幼苗更新生境一致性程度高。结果表明,斑块生境中植物能与专性鸟类、泛性鸟类之间形成种子传播互惠关系,且种子传播效率受到专性鸟类和泛性鸟类传播距离和传播生境的影响。     

红豆杉细胞悬浮培养中不同添加物对细胞生长和紫杉醇合成的影响

采用正交实验检测红豆杉（Ｔａｘｕｓ ｃｈｉｎｅｎｓｉｓ（Ｐｉｌｇｅｒ）Ｒｅｈｄ．）细胞悬浮培养中水杨酸、Ｄ－果糖、甘露醇和硫酸镧对细胞生长和紫杉醇（ｔａｘｏｌ）积累的影响。添加１０ｇ／ＬＤ－果糖,可使细胞的鲜重和干重明显增加;添加６０ｇ／Ｌ甘露醇使细胞的鲜重和干重明显减少;１ｍｇ／Ｌ水杨酸仅使细胞鲜重增加,对干重影响不明显;硫酸镧对细胞生长无明显影响。单独添加这４种物质,紫杉醇含量均下降,同时添加     

Proteins Identified from Saliva and Salivary Glands of the Chinese Gall Aphid Schlechtendalia chinensis

Aphid saliva plays an essential role in the interaction between aphids and their host plants. Several aphid salivary proteins have been identified but none from galling aphids. Here the salivary proteins from the Chinese gall aphid are analyzed, Schlechtendalia chinensis, via an LC‐MS/MS analysis. A total of 31 proteins are identified directly from saliva collected via an artificial diet, and 141 proteins are identified from extracts derived from dissected salivary glands. Among these identified proteins, 17 are found in both collected saliva and dissected salivary glands. In comparison with salivary proteins from ten other free‐living Hemipterans, the most striking feature of the salivary protein from S. chinensis is the existence of high proportion of proteins with binding activity, including DNA‐, protein‐, ATP‐, and iron‐binding proteins. These proteins maybe involved in gall formation. These results provide a framework for future research to elucidate the molecular basis for gall induction by galling aphids.     

太白红杉小孢子的发生和雄配子体的发育

太白红杉(Larix chinensis Beissn)的雄球花7月初开始分化。小孢子囊壁一般包括5～6层细胞：表皮、药室内壁、2～3层中层和绒毡层。绒毡层属于周原质团型。造孢细胞在7月下旬形成,8月上旬形成小孢子母细胞,8月下旬开始减数分裂,于10月上旬进入双线期,并以双线期渡过休眠。翌年3月下旬解除休眠继续进行减数分裂,4月中旬形成四分体,4月下旬到5月初小孢子从四分体内释放出来,小孢子经过连续4次有丝分裂后,于5月中旬形成5-细胞型的成熟花粉粒(雄配子体)并开始散粉。小孢子母细胞发育表现出不同步现象,部分小孢子母细胞在发育过程中出现退化,在小孢子囊内形成空腔。     

Influence of an aqueous extract of Ligustrum lucidum and an ethanol extract of Schisandra chinensis on parameters of antioxidative metabolism and spleen lymphocyte proliferation of broilers

The study was conducted to evaluate the effects of dietary supplementation with different levels of two extracts, an aqueous extract of Ligustrum lucidum (AELL), and an ethanol extract of Schisandra chinensis (EESC) on growth performance, parameters of antioxidative status and spleen lymphocyte proliferation of broilers, respectively. The results showed that neither AELL nor EESC had significant effects on growth performance of broilers. However, malondialdehyde concentration in heart and liver of the broilers were significantly decreased by feeding AELL or EESC. Superoxide dismutase activity in heart, liver, and kidney of broilers were improved by feeding different dosages of AELL or EESC. In contrast, glutathione reductase activity in serum, heart and kidney of broilers was not affected by experimental treatment. In addition, spleen lymphocyte proliferation of broilers was significantly enhanced by feeding different dosages of AELL or EESC. In conclusion, the results suggested that either AELL or EESC may improve antioxidant status and immune function of broilers.     

内蒙东部地区绵羊中华双腔吸虫生物学和流行病学的研究

中华双腔吸虫(Dicrocoelium chinensis Tang et Tang,1978)的生活史虽经研究,但本吸虫在第二中间宿主及终末宿主体内发育的情况尚未经阐明(唐崇惕等,1980).内蒙科右前旗附近数个旗县是本吸虫的流行区,1980—1981年我们在那里进行本项工作,从     

菜蚜二项式抽样设计及其精度分析

１９９０～１９９２年间对杭州市郊区青菜上桃蚜（Ｍｙｚｕｓｐｅｒｓｉｃａｅ）、萝卜蚜（Ｌｉｐａｐｈｉｓｅｒｙｓｉｍｉ）及其混合种群的田间近１００组调查数据,利用每样方（株）虫口不超过数阈值Ｔ（分别为０、１、５、１０、２０、３０、４０）头蚜虫的植株比例（ＰＴ）与种群密度（ｍ,头·株－１）的关系,通过拟合经验公式ｌｎ（ｍ）＝ａ＋ｂｌｎ［－ｌｎ（ＰＴ）］而设计的二项式抽样．通过对三者不同数阈值（Ｔ）的回归决定系数（ｒ２）、种群密度的回归估计方差（Ｖａｒ（ｍ））、抽样精度（以ｄ表示）和实际应用等的比较,结果表明当桃蚜种群处于较高密度即ｍ≥１０时,其理想的Ｔ值为３０;当萝卜蚜种群处于较高密度即ｍ≥５时,其理想的Ｔ值为１０;而它们的混合种群未得到其理想的Ｔ值．数阈值Ｔ为３０和１０可分别用于桃蚜和萝卜蚜的二项式抽样设计．而传统的二项式抽样即０～１抽样由于应用于小白菜上菜蚜的抽样设计时产生很大的误差,不宜采用．     

Low mtDNA variation and shallow population structure of the Chinese pomfret Pampus chinensis along the China coast

In the present study, population genetic structure and genetic diversity of the Chinese pomfret Pampus chinensis, along the China coast were investigated and compared with that from Indonesia using mitochondrial DNA cytochrome b gene sequences. A total of 28 variable sites (including 18 singleton sites and 10 parsimony information sites) were observed and 23 haplotypes were defined in 330 individuals from 11 localities. The haplotype diversity (H_D) of the populations ranged from 0·540 to 0·828, the nucleotide diversity (π) ranged from 0·081 to 0·295%. Pairwise F_ST statistics showed that significant genetic divergence occurred among populations from different geographical regions. The high dispersal capabilities, geographic segregation and ocean currents may be responsible for the present population genetic structure in this species. In addition, a population expansion event during the late Pleistocene period was inferred. The time of population expansion was estimated to occur about 117 000–169 000 years ago.