Transgenic chimera quail production by microinjecting lentiviral vector into the blood vessel of the early embryo

In the past, several strategies have been used to generate transgenic birds. The most successful method has proven to be injection of lentiviral vector into the subgerminal cavity of the newly laid egg. In this study, we directly injected lentiviral vector into the blood vessel of HH13–15 quail embryos to produce transgenic chimeras. In the manipulated, hatched birds, the green fluorescent protein (GFP) gene driven by a cytomegalovirus (CMV) promoter was extensively expressed. All tissues analyzed were GFP‐positive, and gonad cells from some of the manipulated embryos expressed GFP. The semen genome of 21.4% of mature male birds was determined to be GFP‐positive by PCR, indicating these male birds were transgenic chimeras.     

The effect of bark decortication for hiwada production on xylem and phloem formation in Chamaecyparis obtusa

Of all plant materials used to cover the roofs of traditional Japanese buildings, Japanese cypress (Chamaecyparis obtusa) bark, hiwada, has the longest service life and has been used from ancient times. However, wood and bark properties after hiwada harvest have not been evaluated in detail. We studied whether decortication for hiwada production in winter affected xylem and phloem formation. Decorticated trees still preserved all inner bark and part of the outer bark, and both decorticated and control trees had similar annual ring structures at all stem heights in the xylem and phloem. In both xylem and inner bark, no significant difference in ring width at any stem height was found between annual rings before and after decortication. Thus, this study revealed that the decortication of bark for hiwada production does not affect the formation of xylem and the inner and outer bark if decortication is carried out by highly skilled workers in winter.     

Inhibiting factors of symptom development in several Japanese red pine (<Emphasis Type="Italic">Pinus densiflora</Emphasis>) families selected as resistant to pine wilt

Pinus densiflora and P. thunbergii, native to Japan, are highly susceptible to pine wilt disease caused by infection with a pine wood nematode (Bursaphelenchus xylophilus). Trees of these susceptible species have occasionally been found surviving in forests that are extensively damaged by this disease. Seedlings from a part of surviving trees that were selected as resistant families indicate lower mortality rates after the infection. The factors that prevent the symptoms from developing in resistant families of a susceptible species, P. densiflora, as based on the analysis of the pathogens behavior in the tree tissue and the anatomy of the resistant families, are presented in this paper. Nematode populations remained lower in the stems of seedlings from resistant families of P. densiflora than in the stems of non-resistant families. Areas dysfunctional in water transport developed in the stems of resistant families, but did not reach a size large enough to seriously block the ascent of sap. These results suggest that there are systems within the seedlings that prevent nematode migration and reproduction. The 2-year-old seedlings from resistant families of P. densiflora, however, did not suppress the pathogen activity. Numerous branches are a visible characteristic in the seedlings of some resistant families. The arrangement of the resin canals, the only channels in the tree to the pathogen migration, was disoriented at the joints between the branches and the main stem. Such a structure may be effective as a barrier to nematode dispersal.     

我国渔船生产经营主体调查研究的文献综述

对我国渔船生产经营主体调查研究的相关文献进行了梳理,总结现有文献对不同时期渔船生产经营主体情况的研究,分析不同时期渔船生产经营主体存在的问题和解决对策。结果显示,现有研究多关注宏观层面的数据,缺少对微观组织的关注,研究的深度和范围不够。在存在的问题分析方面,多停留在问题表面,未对深层次问题进行分析。在解决问题的对策方面,过度关注政府的作用,而忽视了市场配置资源的作用。     

Photosynthetic response of white spruce families to drought stress

In the context of climate change, an increased frequency of drought stresses might occur at a regional scale in boreal forests. To assess photosynthetic responses to drought treatment, seedlings of 12 open-pollinated families of white spruce (Picea glauca (Moench) Voss) differing in their growth performance were grown in a controlled environment. Gas exchange and chlorophyll fluorescence parameters as well as shoot xylem water potential (WP) were measured for 21 successive days after watering was stopped. Net photosynthesis decreased as stomatal conductance decreased. Net photosynthesis was not affected by drought until WP reached –2.0 MPa when stomata were closed. Initial fluorescence (F and basic fluorescence after induction (F00) were not affected by drought. A progressive decrease in maximal (Fm) and variable fluorescences (Fv), maximum photosystem II (PS II) efficiency (Fv = Fm), effective quantum yield of PS II (FII), photochemical efficiency of open PS II (Fp), and photochemical quenching (qP) was observed at WP < - 1.0 MPa, whereas non-photochemical quenching (qN) remained high throughout the drought treatment. White spruce families with inferior growth performance showed higher values of Fm, Fv, Fv = Fm, Fp, and qN at WP< - 2.0MPa. The results indicated that chlorophyll fluorescence variables can be used as drought markers in relation to present or predicted climate conditions. These could be used for selecting planting stock adapted to drought periods or dry environments. These markers showed that slow-growing genotypes are better adapted to drought conditions than intermediate or fast-growing genotypes in present and predicted drought conditions.     

Activation of PKCalpha and pulmonary vascular remodelling in broilers

OBJECTIVE: The present study was conducted to examine the presence of protein kinase Calpha (PKCalpha) in the pulmonary arterioles of broilers during the development of pulmonary hypertension and pulmonary vascular remodelling. METHOD: One hundred and sixty day-old Avian-2000 broilers were divided equally into a control group and a cold temperature group. All the birds were reared in normal temperatures up to day 14, with the lighting schedule at 24 h per day. Thereafter, birds in the cold temperature group were subjected to low temperature by lowering 1-2 degrees C per day to 12-14 degrees C, and then kept constant until day 49, while birds in the control group were still brooded at normal temperatures. All the birds were fed a diet of pellets throughout the study. Samples of blood were taken from the wing vein, and of heart and lung collected after the birds were killed with an overdose of sodium pentobarbitial, at days 24, 32, 39 and 45 of age, respectively. Right ventricle to total ventricle ratio (RV/TV) and packed cell volume (PCV) were measured. Vessel wall area to vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) was examined using computer-image analytic software. Expression of PKC in pulmonary muscular arterioles was assessed by immunohistochemistry and quantified by measuring optical density (OD) using computer-image analytic software. RESULTS: The incidence of pulmonary hypertension syndrome (PHS) was 12.5% in birds exposed to cold, and 3.75% in the control group (P<0.05). PCV in the cold temperature group was elevated after day 32 (P<0.05), and RV/TV ratio increased on day 45 (P<0.05). Both the WA/TA and mMTPA of birds subjected to cold were significantly elevated (P<0.05). The OD values were not significantly increased before day 32 (P>0.05), however, one week later (at day 39 of age), the difference between the two groups was significant (P<0.05). The increased PKCalpha expression was positively correlated with the values of mMTPA and WA/TA. CONCLUSION: PKCalpha expression was up-regulated during the development of pulmonary hypertension. The activation of PKCalpha might be involved in the development of pulmonary vascular remodelling.     

In vitro multiplication of statice plantlets using sugar-free media

Clumps of statice (Limonium latifolium) plantlets grown photomixotrophically were used as explants and cultured for 25 days on a sugar-free modified Murashige and Skoog (MS) medium in Magenta-type vessels with the number of air exchanges of the vessel (NAE) being 3.8 h⁻¹, at a photosynthetic photon flux (PPF) of 100 μmol m⁻² s⁻¹ and a CO₂ concentration of 1500 μmol mol⁻¹ in the culture room. A factorial experiment was conducted with three levels of 6-benzylaminopurine (BA) concentration, namely 0, 0.25 and 0.5 mg L⁻¹, and two types of supporting material, agar and Florialite (a porous material). The control treatment was a photomixotrophic culture using a sugar- and BA (0.25 mg L⁻¹) containing agar medium in the vessel with NAE of 0.2 h⁻¹, at a PPF of 50 μmol m⁻² s⁻¹ and a CO₂ concentration of 400 μmol mol⁻¹ in the culture room. Leaf area, chlorophyll concentration and net photosynthetic rate were greater in the sugar-free medium treatment with a BA concentration of 0.25 mg L⁻¹ and Florialite than those in the control treatment. The number of shoots and dry weight per clump in the sugar-free medium treatment were comparable to those in the control treatment. Among the sugar-free medium treatments, the number of shoots increased with increasing BA concentration, however, the leaf area, dry weight, chlorophyll concentration and net photosynthetic rate decreased with increasing BA concentration. The use of Florialite significantly enhanced the growth and root induction as well as net photosynthetic rate, compared with the treatments that use agar. These results indicated that sugar-free medium micropropagation could be commercially applied to the multiplication of statice plantlets.     

木质渔船安全问题研究

据统计,2003年辽宁省渔业船舶发生海损事故93起,重大事故14起,沉船300余艘,死亡百余人,直接经济损失近千万元,给渔民造成巨大的生命及财产损失。2000年辽宁省渔业船舶普查结果显示,钢质海洋渔船有1765艘,约占普查总数的5%,木质海洋渔船33219艘,约占普查总数的94.3%。由此可以看     

苹果不同砧木枝条导管分子特征参数比较

以苹果矮化砧木M27、M9、M26、MM106及乔化砧木八棱海棠的一年生枝条为试材,采用组织离析法,研究了苹果不同砧木导管分子在光学显微镜和扫描电镜下形态特征参数,以期为探索苹果矮化砧木致矮机理提供依据。结果表明:八棱海棠与M系砧木导管分子均为孔纹导管;八棱海棠导管分子在长度和尾长上均显著高于M系砧木;M系砧木导管分子宽度、纹孔式、纹孔膜残留、端壁倾斜角与八棱海棠无明显差异。以上结果表明,矮化砧木较乔化砧木具有短导管性、短尾性,这种特性可能是矮化砧木致使树体矮化的原因之一。     

论阔叶树材的生长轮类型和导管排列

生长轮类型分为环孔材、散孔材和半环孔材（或半散孔材）。１９６１年以来国内的《木材学》教科书及某些书刊上出现了辐射孔材、花样孔材、切线孔材及交叉孔材,这是由于导管的大小和管孔排列两者作为分类依据造成的。木材解剖学中这种特征的混乱需要展开讨论,统一认识,以利于木材解剖学的发展。