孑遗树种钟萼木幼树生长特性探讨

研究了5 年生钟萼木幼树株高、地径连年生长、侧枝分生特性。结果表明,调查群体5 年生株高、地径平均值、最大值与最小值分别为2.0 m、3.4 m、0.5 m 和3.2 cm、9.5 cm、0.5 cm;群体幼树株高、地径生长分布遵循正态分布;幼树群体的株高、地径生长在早期表现显著的遗传分化。1～5 年生幼树的株高、地径年生长量表现为：株高在前3 年表现较低生长量,第4、5 年明显加快;地径在第1 年生长量占比较大。幼树株高小于2.0 m 的个体未发现分生侧枝,冠幅小且高生长较缓慢。     

The impact of pH and calcium on the uptake of fluoride by tea plants (Camellia sinensis L.)

BACKGROUND AND AIMS: Tea plants (Camellia sinensis L.) accumulate large amounts of fluoride (F) from soils containing normal F concentrations. The present experiments examined the effects of pH and Ca on F uptake by this accumulating plant species. METHODS: The effect of pH was assessed in two experiments, one using uptake solutions with different pHs, and the other using lime, as CaO, applied to the soil. The effect of Ca was examined by analysing F concentrations in plants supplied with varying amounts of Ca, as Ca(NO3)2, either in uptake solutions or through the soil. KEY RESULTS: F uptake was highest at solution pH 5.5, and significantly lower at pH 4.0. In the soil experiment, leaf F decreased linearly with the amounts of lime, which raised the soil pH progressively from 4.32 to 4.91, 5.43, 5.89 and, finally, 6.55. Liming increased the water-soluble F content of the soil. Including Ca in the uptake solution or adding Ca to soil significantly decreased leaf F concentrations. The distribution pattern of F in tea plants was not altered by Ca treatment, with most F being allocated to leaves. The activity of F- in the uptake solution was unaffected and water-soluble F in the soil was sometimes increased by added Ca. CONCLUSIONS: F uptake by tea plants, which are inherently able to accumulate large quantities of F, was affected both by pH and by Ca levels in the medium. The reduced F uptake following Ca application appeared not to be due simply to the precipitation of CaF2 in solution and soil or to the complexing of Ca and F in roots, although these factors cannot be dismissed. It was more likely due to the effect of Ca on the properties of cell wall or membrane permeability in the solution experiments, and to alteration of F speciations and their quantities in soil solutions following Ca application.     

DIFFERENCES IN SEQUENCES OF RIBOSOMAL DNA SECOND INTERNAL TRANSCRIBED SPACER AMONG THREE MEMBERS OF ANOPHELES HYRCANUS COMPLEX FROM THE REPUBLIC OF KOREA

Abstract  Differences in sequences of ribosomal DNA second internal transcribed spacer (ITS) among Anopheles sinensis, An. lesteri and An. yatsushiroensis from Korea were compared. The PCR amplified rDNA-ITS2 fragments were sequenced directly. Three samples of each species were individually determined.
Lengths of the ITS2 regions were 468bp in An sinensis , 451bp in An lesteri and 453bp in An yatsushiroenesis and GC contents were 44.87 % 46.2 % and 45.7 % respectively. Variations of the sequences ranged from 12.16 % to 30.7 % among the three species. The differences of the rDNA-ITS2 sequences would be useful for molecular identification of the three members of Anopheles hycanus complex from Korea.     

中华绒螯蟹卵巢差减cDNA文库的构建

应用抑制性差减杂交技术构建中华绒螯蟹卵巢两个发育时期的差减cDNA文库。正向差减杂交以Ⅲ期卵巢为试验方、Ⅱ期卵巢为驱动方,反向差减杂交以Ⅱ期卵巢为试验方、Ⅲ期卵巢为驱动方;将所获差减cDNA片段克隆入质粒表达载体,转化大肠杆菌JM109。最后获得的正、反向差减文库分别含863、360个重组子。PCR扩增鉴定正、反向差减cDNA文库的插入片段平均大小分别为360和160bp,表明所构建的差减言语库适合进一步研究中华绒螯蟹卵巢发育相关基因。     

虫草成熟子囊壳、子囊与子囊孢子的电镜观察

虫草子囊壳壁为拟薄壁组织,基部与子座菌丝相联,顶端有一孔口,其内无缘丝,中心腔内无侧丝,基部着生的子囊垂直平行排列。子囊顶端中央是乳状突起,围以隆起的环状膜质边缘。成熟时,其顶端乳状突起膨大,膜质边缘也随之翻卷,中央有一小孔。同一子囊壳内子囊顶端发育阶段不同,说明子囊的形成不同步。子囊内含有两条平行的具横隔的子囊孢子。虫草子囊顶端形态结构即不象虫草属模式种蛹虫草,也不象头状虫草,说明子囊顶端的形态结构的种间差异。     

真菌侵染引发的茶树内源糖苷酶基因差异表达

通过探讨顺-3-己烯醇、芳樟醇氧化物、芳樟醇、水杨酸甲酯、香叶醇、苯甲醇和苯乙醇7种茶叶游离态香气组分和糖苷类香气前体对茶炭疽病菌、茶云纹叶枯病菌、茶轮斑病菌和茶赤叶斑病菌4种致病菌的抑制作用,以及真菌侵染引发的茶树（Camellia sinensis）内源β-樱草糖苷酶、β-木糖苷酶、β-葡萄糖苷酶I、β-葡萄糖苷酶II、β-葡萄糖基转移酶基因的表达差异,结果表明：7种游离态香气组分和糖苷类香气前体对4种致病菌均有明显的抑制作用,其中香叶醇的抑制作用最强,在浓度为0.1mg.mL-1时即对茶炭疽病菌的抑制率达到100%。实时定量PCR结果显示：真菌侵染可不同程度诱导茶树内源糖苷酶和β-葡萄糖基转移酶基因的表达上调,且上调多发生于染病初期。     

茜素红S对中华倒刺鲃幼鱼不同组织抗氧化酶活性和脂质过氧化的影响

以中华倒刺鲃幼鱼[平均体长（12.3±0.6）cm,平均体重（41.8±3.6）g]为研究对象,通过测定不同浓度茜素红S溶液（ARS）浸泡24h后肝脏、脑和鳃组织中抗氧化酶（SOD、CAT、GSH-Px）的活性和丙二醛（MDA）含量,评估ARS对中华倒刺鲃幼鱼的生理生化影响。结果表明:除脑组织GSH-Px随着ARS浓度的升高而不断升高外,肝脏、鳃和脑组织的抗氧化酶活性均表现为低浓度被诱导而高浓度受抑制的规律,与ARS浓度呈抛物线型剂量效应关系。肝脏、鳃、脑组织抗氧化酶活性达到最大值所对应的浓度分别是300、300和400 mg/L。除鳃部MDA含量随着茜素红S浓度升高不断升高外,脑和肝脏组织的丙二醛含量随着ARS浓度的升高呈现出先降低后上升趋势。根据试验的结果,推荐120-200 mg/L为ARS染色标记中华倒刺鲃幼鱼（体长10 cm）的适宜浓度。     

农杆菌介导红江橙遗传转化的研究初报

用红江橙实生苗的上胚轴为材料 ,初步研究以根癌农杆菌介导的 GUS基因转化。结果表明 :以卡那霉素作为选择试剂进行选择培养时 ,Km浓度为 5 0 mg/L;外植体以平放为好 ;抑菌剂选择头孢霉素较好。GUS基因瞬时表达检测 ,70 .4%的外植体呈阳性反应 ;GUS基因稳定表达检测 ,在获得的 1 2株抗性植株中 ,GUS反应呈阳性所占比例为 1 6.7%。     

中华绒螯蟹二株呼肠孤病毒的初步研究

在研究中华绒螯蟹病害的过程中 ,分离到两株呼肠孤病毒 (分别命名为EsRV816和EsRV90 5 )。EsRV816从江苏某养殖场分离 ,EsRV90 5从武汉某养殖场分离。EsRV816和EsRV90 5的病毒粒子为球状对称结构 ,大小分别为 6 5nm和 5 5nm。病毒粒子基因组分别为 10和 12个节段的双链RNA。根据它们的宿主范围、基因组节段数及电泳型 ,这两种病毒很可能属于呼肠孤病毒科的两个新属     

当归对实验性血虚便秘模型小鼠结肠组织形态和黏液分泌的影响

目的：观察当归对实验性血虚便秘模型小鼠的治疗作用及其对小鼠结肠组织形态和黏液分泌的影响。方法：60只KM小鼠,雌雄各半,随机分为6组（n=10）：正常对照组、血虚便秘组、阳性对照组、当归高、中、低剂量组。除正常对照组小鼠外,其余各组小鼠灌胃给予复方地芬诺酯（DNP）,皮下注射乙酰苯肼（APH）,腹腔内注射环磷酰胺（CPA）,复制血虚便秘小鼠模型。从实验的第14天起,当归组小鼠灌胃给予不同剂量的当归煎液（16.67,8.33,4.17 g/kg）,阳性对照组给予常通舒颗粒（5 g/kg）,血虚便秘模型组和正常对照组小鼠给予等体积生理盐水,每日1次,连续28 d。观察小鼠一般状态,检测首粒黑便排出时间（FBDT）、粪便和结肠含水量,取结肠组织进行HE和AB-PAS染色,观察小鼠结肠组织形态变化和黏液分泌情况。结果：与正常对照组比较,血虚便秘组小鼠出现血虚和便秘体征,FBDT显著延长、粪便和结肠含水量显著降低（P<0.01）,结肠黏膜和大肠腺萎缩、黏膜层变薄（P<0.01）,黏液分泌减少。与血虚便秘模型组比较,3个剂量的当归均能改善血虚便秘体征,显著缩短FBDT（P<0.05,P<0.01）,显著升高小鼠结肠含水量（P<0.05,P<0.01）;高、中剂量的当归能显著升高小鼠粪便含水量（P<0.05）;3个剂量当归均能改善血虚便秘模型小鼠的结肠黏膜和大肠腺萎缩,增加结肠黏液分泌,改善结肠润滑功能。结论：当归可改善结肠黏膜萎缩、增加结肠黏液分泌,从而软化粪便促进粪便排出。