Transport-determined early growth and development of jack mackerel Trachurus japonicus juveniles immigrating into Sagami Bay, Japan

Oceanographic conditions and transport processes are often critical factors that affect the early growth, survival and recruitment of marine fishes. Sagittal otoliths were analysed to determine age and early growth for 381 jack mackerel (Trachurus japonicus) juveniles from Sagami Bay on the Pacific coast of Japan. Two separate hatching periods ( December and February-March) were identified. They originated from the spawning grounds in the East China Sea. Early growth and developmental rates of December-hatching fish were lower than those for February-March-hatching fish. It is likely that these differences were determined in the Kuroshio Current during transport from the spawning grounds to Sagami Bay, and the lower December water temperatures in the bay. Origin and hatch dates of juveniles in Sagami Bay were in contrast to previous research on Fukawa Bay, where April-or-later-hatching fish from spawning grounds in the coastal waters of southern Japan constituted about half of the juvenile population. Management of these two jack mackerel stocks needs to consider these differences in hatch date composition and spawning origins, as these differences could affect early growth and subsequent mortality.

Effect of food and temperature on the growth and development of Moina irrasa (Cladocera : Moinidae)

Body length, instar duration, fecundity, and survival rate of Moina irrasa from a subtropical Chinese lake were studied at three food concentrations (4, 8, and 40 mg/L, wet weight) and six temperatures (10, 15, 20, 25, 30, and 35degreesC) in the laboratory. Body length tended to decrease with increase of temperature, while the trend was reversed as food concentration rose. M. irrasa had three juvenile instars, except there were four at 10degreesC, and the number of adult instars showed great variation (3-15). Water temperature and food concentration both affected the duration time of adult instars. The largest broods were from the third to sixth adult instars, depending on food and temperature, and the mean highest number of offspring per brood was 56 at 25degreesC. A significant relationship between body length and brood size appeared at high (40 mg/L) and medium (8 mg/L) food concentrations, while there was no significant relationship at low food concentration except at 25 degreesC. The intrinsic rate of population increase ranged between 0.104 and 1.825 ind./day.

Studies on hybridization effects of different geographic populations of Chlamys farreri - II. The medium-term growth and development of Chlamys farreri populations from China and Russia and their reciprocal crosses

Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F, hybrids derived from Chinese cultural population (CC) female x Russian population (RW) male, Chinese wild population (CW) female x Russian population (RW) male, Russian population (RW) female x Chinese wild population (CW) the study of the medium-term (6, 8, 10, 12 months) growth and development of Chlamys farreri was carried out. The four determined results indicated that there existed different extent heterosis (3% similar to 52 %) for the growth in three types of F-1 hybrids, and the offspring derived from CC female X Rmale had a stronger heterosis among the crosses at the medium-term; the uptrend among traits are wet weight > shell width > shell length > shell height, Chinese cultural population could be recognized as excellent parent, and seasonal variations influence very much on the daily increment and growth rate of each trait of Chlamys farreri and it is only able to survive and could barely grow in winter (6 similar to 8 months), but grows fast in temperate season (10similar to12 months).

Defoliation, nitrogen, and competition: effects on plant growth and resource allocation of Cleistogenes squarrosa and Artemisia frigida

Two species, Artemisia frigida Willd. (C-3, semishrub, and dominant on overgrazed sites) and Cleistogenes squarrosa (Trin.) Keng (C-4, perennial bunchgrass, and dominant or codominant on moderately grazed sites) were studied to determine the effects of defoliation, nitrogen (N) availability, competition, and their interactions on growth, biomass, and N allocation in a greenhouse experiment. The main treatments were: two nitrogen levels (NO = 0 mg N pot(-1), N1 = 60 mg N pot(-1)), two defoliation intensities (removing 60% of total aboveground biomass and no defoliation), and three competitive replacement series (monocultures of each species and mixtures at 0.5:0.5). Our results were inconsistent with our hypothesis on the adaptive mechanisms of A. frigida regarding the interactive effects of herbivory, N, and competition in determining its dominant position on overgrazed sites. Cleistogenes squarrosa will be replaced by A. frigida on over-grazed sites, although C. squarrosa had higher tolerance to defoliation than did A. frigida. Total biomass and N yield and N-15 recovery of C. squarrosa in mixed culture were consistently lower than in monocultures, whereas those of A. frigida grown in mixtures were consistently higher than in monocultures, suggesting higher competitive ability of A. frigida. Our results suggest that interspecific competitive ability may be of equal or greater importance than herbivory tolerance in determining herbivore-induced species replacement in semi-arid Inner Mongolian steppe. In addition, the dominance of A. frigida on overgrazed sites has been attributed to its ability to shift plant-plant interactions through (lap colonization, root niche differentiation, and higher resistance to water stress.

Effects of microcystins on the growth and the activity of superoxide dismutase and peroxidase of rape (Brassica napus L.) and rice (Oryza sativa L.)

Microcystins are naturally occurring hepatotoxic cyclic heptapeptides produced by some toxic freshwater cyanobacterial species. In this study, crude extract of toxic cyanobacterial blooms from Dianchi Lake in southwestern China was used to determine the effects of microcystins on rape (Brassica napus L.) and rice (Oryza sativa L.). Experiments were carried out on a range of doses of the extract (equivalent to 0, 0.024, 0.12, 0.6 and 3 mug MC-LR/ml). Investigations showed that exposure to microcystins inhibited the growth and development of both rice and rape seedlings, however, microcystins had more powerful inhibition effect on rape than rice in germination percentage of seeds and seedling height. Microcystins significantly inhibited the elongation of primary roots of rape and rice seedlings. Determination of the activities of peroxidase and superoxide dismutase demonstrated that microcystin stress was manifested as an oxidative stress. Using ELISA, microcystins were examined from the extract of exposed rape and rice seedlings, indicating that consumption of edible plants exposed to microcystins via irrigation route may have health risks. Significantly different levels of recovered microcystins between exposed rice and rape seedlings Suggested that there might be different tolerant mechanisms toward microcystins. (C) 2004 Elsevier Ltd. All rights reserved.

Growth and milk performance of yak in southern Qinghai area

The Study carried out in Xueshan Township, Guoluo prefecture, Qinghai Province, P. R. China from 1997 to 1999 on 1) Growth regulation of yak from born to adult and 1/4 wild yak from born to one and half year; 2) The effect of nursing or not on the growth and development of dam; 3) Meat performance of local yak; 4)Milk productivity of female yak. It can be served as the theory basis from which crossbreed improvement of yak and government decision could be drawn.

分子调控咖啡酸-O-甲基转移酶（COMT）对木质素合成及植物生长发育的影响

本论文由两部分组成，一、构建来自小麦的COMT的反义表达载体，转化烟草，研究抑制内源COMT对植物木质素合成及其生长发育的影响;二、利用花粉管通道法，将正义和反义COMT基因转化小麦，获得转基因小麦，从而进一步分析。 一、 反义抑制COMT对植物木质素合成及其生长发育的影响 构建含有小麦的咖啡酸-O-甲基转移酶（COMT）cDNA的反义表达载体, 利用农杆菌法转化烟草。 PCR, PCR-Southern 检测显示目的基因片段成功转入烟草基因组。处于营养生长期的转基因植株表型与对照没有明显差异;而发育成熟的转基因植株的植株矮化，茎部木质素含量与对照差异不大，木质素的组成S/G比下降，部分木质部细胞发生变形。我们还发现转基因烟草种子发芽率提高，移栽2个月的子一代转基因植株光合速率、蒸腾速率有所增强。结果表明通过反义抑制COMT将影响木质素合成,并在不同的发育阶段，影响着植物的生长发育。 二、 利用花粉管通道法获得转基因小麦 将构建好的含有Bar基因的正义和反义COMT表达载体利用花粉管法转化两个小麦品种（H4564和C6001），共获得转基因处理的种子1117颗，重新播种后，发育成苗分别为321株，总成苗率为28.7%。通过除草剂PPT筛选，分别获得PPT抗性植株31株。PCR检测抗性植株，获得PCR检测阳性植株5株，总阳性率为0.45%。阳性植株分别为H4564反义处理株1株，C6001的正义和反义处理株各2株。对小麦的植株高度，分蘖数等生理性状的分析发现，转基因小麦的分蘖数减少，植株高度降低。这些生理性状的改变与COMT基因转化的关系将有待于进一步验证。

不同pH缓冲液处理下蚕豆幼苗叶片SOD、POD和CAT活性的变化

利用不同pH值的酸碱溶液处理蚕豆或者离体蚕豆叶片,研究酸碱胁迫下蚕豆叶片保护酶活性的变化。结果表明,离体蚕豆叶片处理10 min和30 min的SOD活性相差不大,整株处理5 h的蚕豆叶片SOD活性远大于处理12 h的SOD活性;离体蚕豆叶片和整株蚕豆处理,较长时间处理下的CAT活性基本上高于短时间处理的CAT活性,短时间处理下(10 min、5 h)POD活性均显著低于对照值,较长时间处理(30 min、12h)下POD活性变化的规律性不强,且变化幅度较小。