华山的硅藻

华山是我国名山之一。这里的植物以前很少有人研究,藻类方面,至今未见有人报道。1976年至1982年作者对该地区进行了多次调查采集,现将研究结果报道如下。     

野蛞蝓危害三七的观察及防治研究

野蛞蝓(Agriolimax agrestis) 危害三七(Panax pseudoginseng)的报道未见,我们是从1964年发现,1965年以后开始研究的。本文就野蛞蝓危害三七的规律及药物防治研究报道如下。     

粳稻花药培养基优化试验研究

培养基的筛选研究,是提高花药培养率的关键问题之一。国内外不少研究人员进行了大量工作,取得了一定的进展。我们自1986年开始以 N_6培养基为基础,对培养基的各个组分进行全面的变量分析和主次因子的研究。我们已报道1987、1988年二个试验周期的结果。本文报道1989、1990年第三、四周期的试验结果。     

小麦离体叶绿体翻译产物与细胞质雄性不育性的研究

关于植物细胞质雄性不育性的研究,从1954年Stephens关于高粱细胞质雄性不育性的研究报道到目前已有不少专题研究报告。从目前已有报道来看,关于线粒体的研究较多。Pring等在对玉米、高粱线粒体DNA     

Theta Corp报道生物技术市场将继续扩大

据Theta Corp近期报道,1995年生物技术研究试剂在美国的销售额将达八亿二千一百万美元。题为“生物技术研究试剂市场”的该篇报道,概括了由基因克隆和核酸合成到肽测序的生物医学研究市场。研究覆盖的三个市场(分子生物学、免疫学和肽)中,分子生物学范围最活跃,1991年销售额为二亿一千八百万美元,比1990年提高22％。该范围的主要产品是酶,占销售的40％;核酸,占24％;试剂盒,占36％。报道预测,截止到1995年,试剂盒将占销售的42％。     

家蝇产卵节律的初步研究

研究家蝇的产卵节律,对家蝇的防治和利用,均具有较重要的理论与实践意义。国内外对家蝇产卵节律的研究尚未见报道。作者从1989年至1990年,对家蝇全产卵期的产卵节律、昼夜产卵节律及几种生态因子对昼夜产卵节律的影响进行了初步研究,现将试验结果报道如下。     

粳稻花药培养基优化试验研究

培养基的筛选研究,是提高花药培养率的关键问题之一.国内外不少研究人员进行了大量工作,取得了一定的进展.我们自1986年开始以 N_6培养基为基础,对培养基原的各个组分进行全面的变量分析和主次因子的研究。我们已报道1987、1988年二个试验周期的结果.本文报道1989、1990年第三、四周期的试验结果。     

黄毛鼠的年龄组

黄毛鼠(Rattus losea Swinhoe)是我国南方的一种主要农田害鼠。关于它们的生物学和生态学已经有过一些报道,伹对它们的年龄组划分和一年中各年龄组的种群数量变动至今还未见有报道。作者在1978和1981年对黄毛鼠的年龄组进行了研究,现报道如下:     

从未传粉的小麦子房诱导单倍体植株

未传粉的子房培养具有理论与应用价值,是当前国内外正在探索的新课题,已有些这方面的研究。我们于1978年离体培养小麦未传粉子房首次获得成功,1979年曾进行了扼要地报道,1980年又获得了单倍体植株,现报道如下。     

2号固氮菌株的筛选及其对水稻产量的影响

自Dbereiner等报道多年生牧草雀稗与雀稗固氮菌以来,国内也有玉米、水稻根系固氮菌存在的研究报道。从1972—78年,我们筛选出具有较高固氮酶活力、生长繁殖快、对水稻有增产作用的2号固氮菌,现报道如下。     

孑遗植物水松(Glyptostrobus pensilis)种群优势度增长规律研究

运用有限空间种群增长的逻辑斯谛模型探讨屏南水松(Glyptostrobus pensilis)种群基面积的增长规律,并通过改进单纯型法进行最优拟合。研究结果表明,洪-Logistic新模型比其它种群增长模型更符合水松种群的实际增长趋势。该模型残差平方和Q为1.7831,内禀增长率为0.7604,特征返回时间Tr为1.3116径级年,最大增长速率出现在第8径级,即胸径为48～54cm时期,平衡位置在环境容量为58.1991m2/hm2处。可见水松种群增长较慢,平衡性脆弱,受破坏后恢复时间较长。研究结果可为屏南水松种群的保护和管理提供理论依据。     

中国金鞘蛾属Goniodoma－新种记述(鳞翅目：鞘蛾科)

记述我国鞘蛾科一新种：中华金鞘蛾Goniodoma sinica sp. nov.。这是金鞘蛾属在我国的首次报道,对属征和世界名录进行了扼要介绍。     

哑蟋属两新种及峨眉哑蟋雌虫的发现(直翅目：蟋蟀科)

哑蟋属两新种及峨眉哑蟋雌虫的发现（直翅目：蟋蟀科）陈军,郑哲民（陕西师范大学动物研究所西安７１００６２）１９９３年在整理陕西师范大学动物研究所蝗虫标本室的蟋蟀标本以及作者于１９９２年夏季在四川采集的蟋蟀标本时,发现有哑蟋属ＧｏｎｉｏｇｒｙｌｌｕｓＣｈ...     

Biocontrol of Two-spotted Spider Mite Tetranychus urticae on Dwarf Hops by the Phytoseiid Mites Phytoseiulus persimilis and Neoseiulus californicus

Two female Phytoseiulus persimilis and their offspring eliminated two-spotted spider mite Tetranychus urticae from hop leaf discs faster than two female Neoseiulus californicus and their offspring at 25°C. A combination of one female of each species and their offspring eliminated spider mites faster than the N. californicus alone, but slower than P. persimilis alone. Air relative humidities of 55% and 93% had no effect on predation. Both predator species cannibalised eggs and juveniles when spider mite numbers were low. In field experiments in 1996, fewer spider mites were recorded where P. persimilis was released, irrespective of the presence of N. californicus. Pest numbers on cv. 'First Gold' were lower than on cv. 'Herald'. No differences were recorded between the numbers of spider mite eggs in predator release treatments on 'First Gold', but fewer active stages of spider mites were recorded on plots with P. persimilis than controls soon after the time of peak pest population densities. On 'Herald', fewer spider mite active stages and eggs were recorded where predators were released than on untreated controls.     

云南猪屎豆属植物订正

This paper is a revision of genus Crotalaria(Papilionaceae) in Yunnan. 30 species and 2 varieties of this genus have been described so far. Hence, there are 27 species, including 4 exotic species, and 4 varieties are distributed in this very province. Among them, 1 new variety, C. mairei var. pubescens, and 3 new combinations, C. yunnanensis var. heqingensis, C. peguana var. qiubeiensis, and C. albida var. gengmaensis, and 1 new record of China, C. humifusa, are included. In addition, 2 species are combined, they are C. jingpingensis to C. prostrata and C. yuanjiangensis to C. medicaginea. Besides, the pollen morphology in some taxa of this genus has been examined.     

Karyotypes of thirteen species of Iris L. from China

Cytological studies were carried out for 13 taxa in the genus Iris from China, of which three species, namely I. subdichotoma, I. delavayi and I. cuniculiformis were endemic to China. The chromosome numbers in somatic cells for each taxon were as follows: I. subdichotoma, 2n=42; I. japonica, 2n=34; I. wattii, 2n=30; I. laevigata, 2n=32; I. ruthenica var. nana, 2n=42; I. collettii, 2n=28; I. dolichosiphon and I. cuniculiformis, 2n=22; I. bulleyana, I. delavayi, I. chrysographes, I. forrestii, and I. lactea var. chinensis, 2n=40. The chromosome number and karyotype of I. cuniculiformis were reported here for the first time and its karyotype formula was 2n=22=4m+6sm+12st(2SAT). The karyotype of I. dolichosiphon was also firstly reported, whose karyotype formula was 2n=22=4m+12sm+6st. The chromosome number and karyotype of I. subdichotoma was newly observed, whose karyotype formula was 2n=42=20m+22sm. Three populations of I. ruthenica var. nana from different localities were investigated and all the three populations had the same chromosome numbers different than previously reported. The karyotype formulae for I. ruthenica var. nana were shown as follows: Zhongdian population, 2n=42=30m+12sm (2SAT); Lijiang population, 2n=42=28m+14sm(2SAT); Nixi population, 2n=42=36m+6sm (4SAT). In addition, the 2n chromosome numbers of three subgenera Limniris, Iris and Nepalensis in the genus Iris from present results and previous reports were summarized. The results showed that the chromosome number varied considerably in subgen. Nepalensis, in which I. subdichotoma was possibly a key species between the genus Pardanthopsis and subgen. Nepalensis. Chromosome number of I. ruthenica was reported as 2n=84 which was twice as much as its variety I. ruthenica var. nana (2n=42) we observed. By comparing with related groups, I. ruthenica is likely to derive from diploid group. Finally, variation of chromosome number and evolutional tendency of karyotype in the genus Iris were also discussed.     

The diatom flora in the ultra-oligotrophic Lake El'gygytgyn,Chukotka

Lake El'gygytgyn, an impact crater lake in northeastern Siberia, was analysed based on water-column characteristics and the modern and sub-recent diatom flora. Vertical temperature, conductivity and oxygen profiles, as well as ionic concentrations in the lake water, reveal that Lake El'gygytgyn is a clear, cold-monomictic, ultra-oligotrophic high-Arctic lake with high light-penetration depth. We identified 113 diatom taxa, of which only 2 species are planktic diatoms. Cyclotella ocellata is the only quantitatively significant diatom present in the modern phytoplankton community, and is also predominant in a short sediment core, which probably reflects the mid- and late-Holocene environmental history of Lake El'gygytgyn. Pliocaenicus costatus var. sibiricus is also common but of minor importance. This is the first evidence of P. costatus var. sibiricus outside the Lake Baikal region.     

PERIPHYTIC DIATOM ASSEMBLAGES FROM BATHURST ISLAND, NUNAVUT, CANADIAN HIGH ARCTIC: AN EXAMINATION OF COMMUNITY RELATIONSHIPS AND HABITAT PREFERENCES

Diatoms are potentially the most important biomonitors of environmental change in high arctic lakes and ponds, but to date few autecological data are available. Because of the shallow nature of many of these water bodies, a large proportion of taxa are periphytic and planktonic diatoms are absent for the most part. By determining the microhabitat and substrate preferences of these benthic diatom taxa, the potential exists to infer past changes in available habitats from fossil diatom assemblages collected from sediment cores and ultimately to reconstruct past environmental and climatic changes responsible for these shifts in habitat availability. To refine our understanding of high arctic diatom habitat preference, the common diatom taxa found on submerged moss (bryophyte), sediment, and rock substrates from lakes and ponds on Bathurst Island, Nunavut, Canadian High Arctic were examined. The relationships among key limnological variables and the common taxa from each habitat were examined. Many diatom taxa exhibited varying degrees of microhabitat preference, with moss representing the more unique habitat. In addition, the following limnological variables significantly ( P ≤ 0.05) explained the species variance for each of the three substrates: Na ⁺ and total nitrogen for moss; total phosphorus (filtered) and pH for rock; and Fe^{3 +} , total phosphorus (unfiltered), total nitrogen, temperature, and pH for sediment. These data can be used to help interpret monitoring and paleolimnological studies in this environmentally sensitive region.     

江汉平原47号钻孔中的化石硅藻及其在古环境分析上的意义

江汉平原47号钻孔,位于湖北省江汉平原的江陵县,在其上段的46.6-2.2m层位上,有丰富的化石硅藻,约有26属148种,其中绝大多数是现存的淡水种类,并以附生性、沿岸带和浅水性的种类为主。种类较多的属有:Navicula(28种)、Cymbella(23种)、Achnanthes(15种)、Gomphonema(14种)和Eunotia(13种)。主要种类有Gomphonema tropicale var. nonpunctatum、Cyclotella comta、Cocconeis placemula vat. lineata和Stephanodiscus dubius等。硅藻中的种数(种/层)和数量(个/每克干沉积物)经历了一个从无到有、由少到多再逐渐减少直至消失的过程。这反映了水体环境也相应地经历了一个漫长的变迁过程:河流(可能是长江古道)→边滩和河漫滩→泛滥平原的积水洼地(湖泊或沼泽)→水体变深加宽→水体消失。从不同沉积相中各种类型(适酸碱度不同)的硅藻比例(即硅藻种谱),可以推测当时水体的酸碱度的变化不大,在中性或中性偏碱的范围。由化石硅藻并结合孢粉的矿物分析,可以推测当时硅藻大量生长繁殖时期的水温较凉,气候可能偏冷。硅藻的数量与沉积物的平均粒度呈明显的相关性,硅藻的种数与沉积物的平均粒度也呈明显的相关性。