Studies on the Nucleic Acid and Protein Content in the Cotyledon Cells of Lotus Using Fluorescent Imaging System with a Scientific grade Charge Coupled Device

Enzyme dissociated cotyledon cells were obtained from red lotus ( Nelumbo sp. ) on the 5th day and 20th day after fertilization respectively. DNA, RNA and total protein content of individual 5 d and 20 d cell were measured correlatively by microfiuorescent imaging system with a cooled scientific-grade Charge coupled deviced (CCD) camera. The results showed that DNA content of the 20 day cell has become polyploidized from 4C to 8C approximately. The window analysis indicated that relative content of RNA and total protein of the 20 day cell was more than 11 times that of the 5 day cell in the same 4C DNA window respectively. The multiple in-creased of RNA and total protein content was about the same as that of DNA in 2 DNA windows (4C and 8C) of the 20 day cell. These data showed that the enormous accumulation of storage proteins in the cotyledon cells of red lotus depends on both DNA ploidy and selective expression of the subunit genes of the storage proteins during the developmental process.     

Genetic diversity of endangered brown bear (Ursus arctos) populations at the crossroads of Europe, Asia and Africa

Aim  Middle East brown bears ( Ursus arctos syriacus Hemprich and Ehrenberg, 1828) are presently on the edge of extinction. However, little is known of their genetic diversity. This study investigates that question as well as that of Middle East brown bear relationships to surrounding populations of the species.
Location  Middle East region of south-western Asia.
Methods  We performed DNA analyses on 27 brown bear individuals. Twenty ancient bone samples (Late Pleistocene to 20th century) from natural populations and seven present-day samples obtained from captive individuals were analysed.
Results  Phylogenetic analyses of the mitochondrial sequences obtained from seven ancient specimens identify three distinct maternal clades, all unrelated to one recently described from North Africa. Brown bears from Iran exhibit striking diversity (three individuals, three haplotypes) and form a unique clade that cannot be linked to any extant one. Individuals from Syria belong to the Holarctic clade now observed in Eastern Europe, Turkey, Japan and North America. Specimens from Lebanon surprisingly appear as tightly linked to the clade of brown bears now in Western Europe. Moreover, we show that U. a. syriacus in captivity still harbour haplotypes closely linked to those found in ancient individuals.
Main conclusion  This study brings important new information on the genetic diversity of brown bear populations at the crossroads of Europe, Asia and Africa. It reveals a high level of diversity in Middle East brown bears and extends the historical distribution of the Western European clade to the East. Our analyses also suggest the value of a specific breeding programme for captive populations.     

Historical presence of the sturgeon Acipenser sturio in the Rhône basin determined by the analysis of ancient DNA cytochrome b sequences

Sturgeon disappeared from the Rhône River in the mid 70’s without certitude about which species it was and about the existence of a sympatry between European sturgeon, Acipenser sturio, and Adriatic sturgeon, A. naccarii, in this watershed. In order to reach a reliable specific determination of this extinct sturgeon population, archaeozoological remains of the Jardin d’Hiver in Arles city, on the Rhône river banks, were genetically analysed, following strict criteria of authentication for the ancient DNA work. The rich collection of Arles sturgeon bone remains stems from human activities between the 6th and the 2nd Century BC. Sequences of 86 bp of the cytochrome b gene were obtained on four bones, from different anatomical parts of the fish and from different archaeological layers. All gave A. sturio diagnostic sequences. This preliminary analysis is an essential first step in the project of sturgeon reintroduction in the Rhône River. Thus, further analyses on a larger sample are necessary to comfort this result and to solve the question of sympatry with A. naccarii.     

荷花品种比较试验

从始蕾、始花期、群体花期、着花密度、株型、花型等方面对41个荷花品种进行比较试验。结果表明,大株型荷花品种以祝福、西湖红莲最好;中小株型以金珠落玉盘、小精灵、绿云、小碧台、玉碗、红宝石、醉半熏、淡云、雨花、桃红小碗、红碗莲、瑶池春暖等12个品种最好,具有较高的观赏价值和商品价值。     

Photosystem Development in Dark-grown Lotus (Nelumbo nucifera) Seedlings (in English)

It is well known that no chlorophyll synthesis and photosystem biogenesis have been detected in dark-grown angiosperm seedlings. However, in this report, we showed that both PSⅡ and PSⅠ could be formed in dark-grown lotus ( Nelumbo nucifera Gaertn.) seedlings. Lots of evidence were given: First, during the dark-grown period, the single fluorescence emission peak at 679 nm in lotus embryo red-shifted and transformed into the normal PSⅡ fluorescence emission; Simultaneously, PSⅠ fluorescence emission at 730 nm appeared and increased obviously; Second, with partial denaturing SDS-PAGE method, PSⅠ chlorophyll-protein complex could be clearly separated from 10 days dark-grown lotus seedlings; Third, the existence of Lhca1 was also proved by Western blots. Moreover, measurements of electron transfer rate demonstrated that both PSⅡand PSⅠ core in dark-grown lotus seedlings were photochemically active.     

鄱阳湖围垦区藕塘越冬白鹤的时间分配与行为节律

2016年12月—2017年3月,采用瞬时扫描法研究了鄱阳湖围垦区藕塘生境中白鹤Grus leucogeranus越冬期的行为,共扫描2560次,23219只次,包括18031只次成鹤和5188只次幼鹤。结果表明,觅食(41.78%)、警戒(25.02%)、修整(15.00%)和休息(10.84%)是白鹤越冬期的主要行为。与自然生境相比,藕塘生境中白鹤主要采取多休息和修整的策略来节省能量支出。成鹤的觅食行为(35.29%)显著低于幼鹤(62.42%)(F_(1,12)=45.977,P0.01),警戒行为(28.66%)则显著高于幼鹤(10.26%)(F_(1,12)=38.975,P0.01)。家庭群成鹤觅食行为(43.96%)极显著高于非家庭群成鹤(27.04%)(F_(1,12)=60.169,P0.01)。家庭群成鹤需要喂食幼鹤,它们花费更多的时间觅食弥补能量的消耗。行为节律上,白鹤各时段觅食行为占总行为的比例均较高,11:00—11:59出现明显高峰,占总行为的48.64%。警戒行为无明显的低谷和高峰。成鹤在各时段的觅食行为比例均明显低于幼鹤,成鹤和幼鹤的觅食曲线变化趋势相似,即觅食比例的升高和降低比较同步。成鹤在各时段的警戒行为和修整行为比例均明显高于幼鹤,成幼鹤的休息行为比例在各时段差别不大,均在14:00—14:59有个明显的高峰。家庭群成鹤的觅食行为比例几乎在各时段均明显高于非家庭群,家庭群成鹤的修整行为和休息行为在大部分时段均低于非家庭群成鹤。因此家庭群成鹤采取多取食,少休息和修整的策略提高自身的适合度,同时保证对后代的抚育。     

人工高盐环境中可培养嗜盐菌的分离与分析

嗜盐菌属于极端微生物中的一种,其结构与理化性质的研究受到国内外同行的关注.国际同行在嗜盐菌的研究领域已经做了大量的工作,而国内的研究工作相对较少.     

古代DNA研究中污染的控制和识别

现代分子生物学中PCR技术的发展使得直接分析古代动植物和人类材料中的DNA成为可能,这为考古学、人类学和古生物学提供了一种新的研究手段。但由于PCR技术的高度敏感性和古代DNA含量的极其微量性,古代DNA研究也极易受现代DNA污染。如何甄别所获得的DNA是真实的古代DNA而不是污染的现代DNA是所有古代DNA研究工作者都要面临的挑战,污染的控制和识别也因此成为古代DNA研究中一个至关重要的问题。本文将着重讨论在古代DNA研究的各个步骤中应如何进行有效的污染控制和识别。     

Evidence for Megalake Chad, north-central Africa, during the late Quaternary from satellite data

The existence of a very large Lake Chad during the late Quaternary, Megalake Chad, has long been questioned. A Megalake Chad would present strong evidence for climatic fluctuations of great magnitude during the Holocene in tropical Africa. In this paper we used satellite data from Landsat and Modis sensors to collect and analyse new information on landforms in a 2 000 000 km² region of the Lake Chad Basin. We detected 2300 km of remains marking the ancient shoreline of Megalake Chad. The satellite data also indicated many Saharan rivers and relict deltas leading to the long paleoshoreline. Large dunefield flattenings were observed and interpreted as the result of wave-cut erosion by the paleolake. Similarities were noticed between the landforms observed along the paleoshoreline of Megalake Chad and that of the former Aral Sea. This finding has significant consequences for reconstructing paleohydrology and paleoenvironments through the Lake Chad basin, and continental climate change.