光合细菌 Rhodopseudomonas capsulata BG-6 的分离、鉴定、生长特性及其氮素代谢的初步研究

本篇论文报道了从北京市高碑店地区污水中分离获得的一株光合细菌的鉴定过程。报道了对其生长特性，工厂发酵罐大规模生产进行研究的结果，报道了对该菌株氮素营养和氮素代谢特点所做的初步研究的结果。整个工作有利于今后系统研究该菌株的代谢特点和利用该菌株进行实际应用。

6-苄基腺嘌呤在植物中的吸收、运转、代谢及其对蒜苔营养物质再分配的调节

本文以黄瓜幼贡和离体蒜苔为材料，研究了细胞分裂素BAP在植物中的吸收、运转、代谢，及其对离体蒜苔营养物质再分配的调节。 黄瓜幼苗功能大速、大量地吸收外源BAP，其吸收的方式为被动吸收。BAP的吸收和其浓度在相当在的范围内（0.00015-10ppm）成严格的线性关系;饲喂BAP后的幼苗转移到无BAP的营养液培养时，幼苗体内的BAP大量外漏，进入营养液，直到细胞内外的BAP浓度大致平衡。 去根黄化黄瓜苗吸收外源BAP后迅速运转。约有6%的BAP能到达子叶。BAP的运转基本上只在初期，即吸收开始后最初的几个小时中进行光照对BAP的运转有促进作用。在离体蒜苔中，苔茎中部注射的BAP能极性地向上运转并在珠蒜中积累，这个过程是随着时间而逐渐进行的，到第20天，约有48%的BAP在珠蒜中积累。 去根黄化黄瓜苗下胚轴茎部吸收BAP后迅速代谢。首先形成大量的BAP—核苷，随后又迅速减少，而BAP—葡萄糖苷逐渐增加，成为主要的代谢物。BAP—核苷含量的这种变化可能是BAP吸收后只在最初的内个小时中运转这一现象的直接原因。在下胚轴上部，初期BAP—核苷含量极高，随后逐渐减少，也说明黄瓜苗中BAP—核苷是BAP的动转形式。BAP浓度极低时，其代谢速度稍有放慢。 BAP处理蒜苔对其内3H—葡萄糖的分布有显著影响，在顶端处理时促进葡萄糖向珠蒜中积累，在茎部处理时刺激葡萄糖向茎部移动。幼嫩和迅速衰老的蒜苔，其对BAP的敏感性差异颇大。BAP调节蒜苔营养物质再分配的作用可能是通过刺激处理部位的生长而产生的。

St. John, USVI mission report, NOAA/NOS/NCCOS/CCMA/Biogeography Branch, July 6 - July 17, 2009

The intent of this field mission was to continue ongoing efforts: (1) to spatially characterize and monitor the distribution, abundance and size of reef fishes, and the abundance of macroinvertebrates (conch, Diatema, lobster) within and around the waters of the Virgin Islands National Park (VIIS) and newly established Virgin Islands Coral Reef National Monument (VICR), (2) to correlate this information to in-situ data collected on associated habitat parameters, (3) to use this information to establish the knowledge base necessary for enacting management decisions in a spatial setting and (4) to establish the efficacy of those management decisions. An additional focus this year, was to evaluate a new habitat data collection method for RHA sites (MSR and some Coral Bay sites). There are concerns that the cylinder habitat data are not reflective of the fish transect habitat. To address this, we collected habitat data at 5x4 m increments along the transect in addition to data collected using the cylinder method. We are currently assessing the potential differences between these methods and preliminary results indicate that the average difference of coral cover estimates between the two methods was 4.1% (range 0-11%) based on 16 sample sites. In addition, Erinn Muller, a Nancy Foster Fellowship recipient, collaborated with the Biogeography Branch to examine the spatial distribution of coral diseases, to provide baseline information on disease prevalence over varying spatial scales and to establish spatial distributions of coral diseases around St. John.

Individual growth rates and movement of juvenile white shrimp (Litopenaeus setiferus) in a tidal marsh nursery

We measured growth and movements of individually marked free-ranging juvenile white shrimp (Litopenaeus setiferus) in tidal creek subsystems of the Duplin River, Sapelo Island, Georgia. Over a period of two years, 15,974 juvenile shrimp (40−80 mm TL) were marked internally with uniquely coded microwire tags and released in the shallow upper reaches of four salt marsh tidal creeks. Subsequent samples were taken every 3−6 days from channel segments arranged at 200-m intervals along transects extending from the upper to lower reach of each tidal creek. These collections included 201,384 juvenile shrimp, of which 184 were marked recaptures. Recaptured shrimp were at large an average of 3−4 weeks (range: 2−99 days) and were recovered a mean distance of <0.4 km from where they were initially marked. Mean residence times in the creek subsystems ranged from 15.2 to 25.5 days and were estimated from exponential decay functions describing the proportions of marked individuals recaptured with increasing days at large. Residence time was not significantly correlated with creek length (Pearson=−0.316, P=0.684 ), but there was suggestive evidence of positive associations with either intertidal (Pearson r=0.867, P=0.133) or subtidal (Pearson r=0.946, P=0.054) drainage area. Daily mean specific growth rates averaged 0.009 to 0.013 among creeks; mean absolute growth rates ranged from 0.56−0.84 mm/d, and were lower than those previously reported for juvenile penaeids in estuaries of the southeastern United States. Mean individual growth rates were not significantly different between years (t-test, P>0.30) but varied significantly during the season, tending to be greater in July than November. Growth rates were size-dependent, and temporal changes in size distributions rather than temporal variation in physical environmental factors may have accounted for seasonal differences in growth. Growth rates differed between creeks in 1999 (t-test, P<0.015), but not in 1998 (t-test, P>0.5). We suggest that spatial variation in landscape structure associated with access to intertidal resources may have accounted for this apparent interannual difference in growth response.