Pollen records of Holocene vegetation and climate changes in the Longzhong Basin of the Chinese Loess Plateau

Pollen records with an average time resolution of 20—200 years from Holocene loess sections at Dingxi, Qin'An, and other localities of Gansu Province reveal a detailed history of vegetation and climate changes in the western Loess Plateau. For most time of the Holocene, the landscape was dominated by grasslands or forest steppes. However, during the middle Holocene (7.5—5.8 ka BP), relatively dense forests developed, and the endemic vegetation flourished, suggesting a much warmer and more humid climate condition than the present. Superimposed upon this general pattern are several dry intervals marked by the episodic expansion of grasslands or forest steppe. Xeric vegetation expanded after 3.8 ka BP, indicating a trend towards dry conditions.     

马尾松愈伤组织诱导条件的研究

采用马尾松(Pinus massoniana Lamb.)成熟合子胚为起始材料,经过0.1%升汞溶液7~9min消毒后,接种于WPM培养基上,在温度26℃,光照强度2 000~3 000 lx,光照时间16 h/d的条件下培养得到无菌苗.采用无菌苗的各器官作为外植体在光照条件下进行愈伤组织的诱导条件的研究,结果显示,以幼茎为外植体,在含GD 6-BA 4.0 mg.L-1 NAA 0.10 mg.L-1 0.3%~0.4%活性碳(CA) 500 mg.L-1水解酪蛋白的培养基上,愈伤组织诱导率可达到93%.     

Arthropods associated with nests of Cacicus sp. and Psarocolius sp. (Passerida: Icteridae) in varzea forest near the meeting of the rivers Negro and Solimões (Central Amazonia,Brazil) at high water

We analysed the arthropod fauna from nine nests of Cacicus sp. and nine nests of Psarocolius sp. (Passerida: Icteridae), in the varzea forest of Central Amazonia, Brazil, during high water, establishing these nests as one of the probable refuges for several arthropods performing vertical migration during periods of flooding and high water, besides discussing the role of these arthropods in the nests. We also evaluate the effectiveness of the extraction of arthropods from nests using an apparatus based on the Berlese–Tullgren funnel. We obtained 15,128 arthropods from three subphyla, five classes and 16 orders. The nests were shown as complex ecosystems sheltering groups from different functional and trophic categories and revealed striking differences from those of terra firma, remarkably in Blattaria, Arachnida and Pseudoscorpiones. The increasing volume of the funnel and time of heat exposure was shown to be appropriate for extraction of the arthropods from the bulky nests of these birds.     

Identification of sex pheromones of four economically important species in genusDendrolimus

The female-produced sex pheromone of Dendrolimus superans was identified by gas chromatography (GC), coupled GC-mass spectrometry (GC-MS), electroantennographic (EAG) studies and field tests as a blend of (Z,E)-5,7-dodecadienal (Z5,E7-12:Ald) and (Z,E)-5,7-dodeca- dien-1-ol (Z5,E7-12:OH). In D. kikuchii, (Z,E)-5,7-dodeca- dien-1-yl acetate (Z5,E7-12:OAc) and Z5,E7-12:OH were found by GC and GC-MS analyses. However, in EAG studies male antennae were more sensitive to Z5,E7-12:OAc and (Z,E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr) than Z5,E7-12:OH. For D. spectabilis, Z5,E7-12:OH had been previously reported as the sex pheromone. However, in our studies, traps baited with Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr in a ratio of 1:1:1 caught three times more males than those baited with Z5,E7-12:OH alone. Relatively strong EAG responses were elicited from male antennae by Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr, but in addition to Z5,E7-12:OH, only very small amounts of Z5,E7- 12:OAc was found in the pheromone gland. These facts suggest that Z5,E7-12:OAc is a pheromone minor components and Z5,E7-12:OPr is a sex attractant in D. spectabilis. For D. tabulaeformis, Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12: OPr were found in extracts of pheromone glands of female moths, and the three compounds elicited strong EAG responses from antennae of male moths. These three compounds have been reported as a sex attractant of D. tabulaeformis, and our data confirm their roles as components of the sex pheromone of this species. The role of blend components in antagonizing cross attraction between congeners is discussed.     

Host tree unsuitability recognized by pine shoot beetles in flight

Summary In spring, the landing rate of flying European pine shoot beetles,Tomicus piniperda L., on injured Scots pine diminishes as colonization continues. This is due to olfactory cues that indicate progressive host degradation. Verbenone was shown to play a role in the beetle's recognition of this unsuitability of a formerly suitable host, since the compound was increasingly released from colonized tree sections as they aged, but not from uninfested sections. Also, the release of verbenone at natural rates in the forest inhibited the attraction of beetles to host monoterpenes.     

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Summary

Five early ontogenic stages of Scomberomorus lineolatus (C. &; V.) ranging in standard length from 18·4 mm to 99·5 mm are described.

Direct comparison of these early stages with those of S. commerson (Lac.) showed differences in the number of gill rakers, the length of preopercular spines and the position of the anal fin in relation to the second dorsal fin. In the case of S. guttatus (Bl. &; Schn.) the gill rakers are of the same number as in S. lineolatus but the preopercular spines decrease in size from above with the upper two subequal in size and none projects beyond the operculum.

In the earlier stages, S. lineolatus could be easily distinguished from S. guttatus by the absence of the bluish green coloration characteristic of S. guttatus. In later stages when the coloration has developed in both the species the only marked difference between the two is in the nature of the bent portion of the lateral line which is wavy in S. lineolatus and straight in S. guttatus.

The number of vertebrae is 46 in S. lineolatus; 42–45 with 43·9 as mean in S. commerson and 47–52 with 49·7 as mean in S. guttatus.     

云南松-蓝桉混合浆漂白的研究

改进的硫酸盐蒸煮浆比常规硫酸盐浆有较好的漂白性，在相同的漂白工艺条件下，改进的硫酸盐蒸煮浆比常规硫酸盐浆所用的化学药品少而成浆白度高。用改良硫酸盐法制得的浆比常规硫酸盐法制得的浆易漂；用氧碱次氯酸钠漂白，蓝桉比例大的成浆白度高，比例少的白度较差，且氧碱次氯酸钠漂白比常规次氯酸钠漂白成浆白度可提高2～3倍；过氧化物H2O2的漂白过程聚合度下降较少，很适合强煮弱漂的制浆工艺，成浆白度与次氯酸钠相差不大，但可减少污染。用蓝桉60％的混合材制的浆粕，进行纺丝验证试验，纺丝的各种性能好，能纺出质量较好的粘胶纤维。     

药用植物松塔的化学成分研究

目的：对松科（Pinaceae）华山松（Pinu sarmandii Franch．）松塔的化学成分进行研究，以期寻找活性成分。方法：松塔的乙醇冷浸提取浸膏，依次用石油醚、氯仿、乙酸乙酯和正丁醇萃取，分别得到石油醚、氯仿、乙酸乙酯和正丁醇的萃取物。氯仿和正丁醇萃取物用正、反相色谱法，MCI、Pharmadex LH-20凝胶柱色谱法和HPLC法分离，分离得到6个化合物。结果：根据理化性质和利用NMR、ESI—MS等波谱技术鉴定化合物结构，鉴定了其中的4个化合物：异海松烷（Ⅰ）；Dehydroabietic acid（Ⅱ）；β-谷甾醇（Ⅲ）；β-胡萝卜苷（Ⅳ）。结论：其中化合物Ⅰ～Ⅱ为首次从该种植物中分离得到。     

不同毒力松材线虫杂交后代的繁殖力和致病力的比较

为了解松材线虫致病力及繁殖力的遗传变异规律,以松材线虫强毒虫株及弱毒虫株为亲本进行杂交试验,并对杂交后代的繁殖力和致病力进行比较。结果表明:不同亲本间杂交成功率不同,同一对亲本的正交、反交成功率亦不同。大多数杂交后代群体在灰葡萄孢上和马尾松苗体内的繁殖力与亲本之间差异显著。杂交后代群体及强毒亲本接种马尾松5周后的致萎蔫率达90%~100%,而弱毒亲本接种的植株在10周后仅20%出现轻微的萎蔫症状。统计分析表明,松材线虫致病力与其在树体内的繁殖力间存在中等程度的正相关性,与灰葡萄孢上的繁殖力相关性较弱。聚类分析表明,不同毒力松材线虫杂交后代群体的致病力与繁殖力之间没有亲缘关系偏向,繁殖力与致病力不存在伴性遗传。     

马尾松子代测定及优良家系选择

以15 a生马尾松子代林为研究对象,通过调查51个家系及1个对照的树高、胸径、地径等生长性状,计算其家系遗传力、单株遗传力、变异系数等遗传参数.结果表明:不同家系间树高、胸径、材积等性状存在极显著差异;树高、胸径、材积变异系数分别为12.37%,27.55%和57.85%,优树子代性状生长表现较好,具有较大的遗传变异潜力;树高、胸径和材积的家系遗传力分别高达79.87%,65.23%和66.6%.以各性状平均值+1/4标准差为临界值,按材积、胸径、树高4∶3∶3进行综合评价,选择7个生长表现好的家系,其树高、胸径、材积平均值为11.08 m,14.45 cm和0.095 9 m3,分别比对照高6.6%,21.3%和37.8%,平均遗传增益分别为4.22%,7.84%和18.29%.