SOME REMARKS ON THE PHOTOSYNTHESIS OF GREEN PLANTS

1. It is suggested that in the assimilation process of green plants the reduction of the CO₂ takes place with the help of Fe⁺⁺ ions (present in the chloroplast) under the influence of light, which is absorbed by a sensitizing chlorophyll-CO₂-complex. 2. It seems that the chlorophyll has to fulfill two different functions depending on its situation in the chloroplast. The chlorophyll molecules on the surface of the lipoid phase (in contact with an aqueous phase containing Fe⁺⁺) combine with CO₂ to form a light absorbing chlorophyll-CO₂-complex and in this way take part in the reduction of the CO₂. The light energy is also absorbed by the greater portion of the chlorophyll, which is dissolved in the interior of the lipoid phase, and eventually handed over to the chlorophyll molecules on the surface. 3. The photosynthetic unit of Emerson and Arnold may be determined by the ratio: See PDF for Equation so that for every chlorophyll molecule on the surface there are about 500 molecules in the interior, which provide it with the necessary quanta.     

虎斑夜鳽分布与亚群态势研究

本世纪以来对虎斑夜鳽分布地点的新发现,表明该种从滨海到内陆漫布于中国长江以南广大地区,并向北渗透直逼东洋界北限秦岭-淮河一线;作者据此将各地的虎斑夜鳽初划为11个亚群,提出目前该种存有3个相对健康而稳定的亚群,即黄山-天目山亚群、南岭亚群和广西亚群,且每个亚群的分布范围均至少不会小于5000km2,其中以黄山-天目山亚群的记录由历史至现今相对最为长久而完整,进而提出今后在上述诸亚群范围之外还会有新的发现.文中指出,尽管近期对虎斑夜鳽分布状况有了新认识,目前仍可视该种的受胁等级为濒危.     

池鹭繁殖种群数量、活动规律和生物生产量的研究

本文报道池鹭种群数量变动,种群活动,雏鸟生长和生物生产量。种群活动可划分为适到期,运情期,繁殖期,同鸟活动期,集群活动和迁离期。１９９０,１９９１二年繁殖前种群密度分别为１３００只／ｈｍ＾２和１４０１只／ｈｍ＾２,繁殖后增加密度为２０８７只／ｈｍ＾２和２２４８只／ｈｍ＾２。雏鸟体重增长曲线议程为：Ｗ＝２８６／１＋ｅ＾－０．４０９（ｔ－１２．６）１９９０,１９９１年繁殖种群的生物生产量分别为１９７．     

苍鹭营巢习性的初步观察

2000年3－4月在辽宁省凌源市对苍鹭的营巢习性进行观察表明：苍鹭在营巢过程中雄性外出取材,雌性筑巢,营巢期6－9天;雄性取材次数随着营巢天数的增加而增多,每日取材次数有两个高峰期,即上午7－9时、下午3－5时;巢平均值为外径50cm,内径29．2cm,巢高24cm,巢深11cm,巢材主要为树木枯枝。     

MULTIPLE COLONIZATIONS OF ASPLENIUM ADIANTUM-NIGRUM ONTO THE HAWAIIAN ARCHIPELAGO

The extreme isolation and mid-Pacific origin of the Hawaiian archipelago has ensured that all indigenous organisms have arrived via long-distance dispersal or have evolved from successfully colonizing species. Although this isolation has also produced high rates of species endemism in angiosperms (89% or more), that rate in pteridophytes is considerably less (76%). The ratio of native species to the estimated number of original successful colonizing species in angiosperms (3.4) is more than double that for pteridophytes (1.6). One possible explanation for the lower speciation rate in pteridophytes is that populations of these species are more likely to experience interpopulational gene flow because of the great vagility of their wind-dispersed spores. We conducted isozymic surveys of populations from the island of Hawaii of the indigenous allotetraploid species Asplenium adiantum-nigrum, putatively derived from two strictly European diploid taxa. Our data support multiple hybrid origins for the populations surveyed, with a minimum of 3, and possibly as many as 17, discrete hybridization events having produced the genetic diversity observed. Since the parental taxa are not found in Hawaii, each hybrid lineage must have arrived in the archipelago independently of the others. Similar long-distance, repeated dispersal events may be occurring between insular and noninsular populations of other native pteridophytes in Hawaii and in other insular regions of the world, thus contributing to the relatively low rates of speciation and insular endemism in this ancient group of plants.     

绿茶抗氧化剂成分抑制突变作用的初步研究

绿茶水溶性提取物及茶叶中抗氧化剂成份具有明显的抑制AFB_1及Bap诱导的鼠伤寒沙门氏菌回复突变作用。这种抗氧化剂成份还可以抑制AFB_1和Bap诱导的V79细胞基因正向突变,以及AFB_1诱导的V79细胞SCE和染色体畸变。本实验结果提示,绿茶中抗氧化剂成份可能对AFB_1及Bap的致癌性具有抑制作用。本文就茶叶抗氧化剂抑制突变的可能机制进行了初步讨论。