沙蒿木蠹蛾生物学特性研究

沙蒿木蠹蛾Holcocerus artemisiae Chou et Hua是危害油蒿Artemisia ordosica Krasch和籽蒿A. sphaerocephala Krasch的重要钻蛀性害虫, 以幼虫蛀食根部, 导致寄主植物长势衰弱甚至死亡。为有效控制其危害, 我们对该虫形态和生物学特征结合野外调查和室内饲养观察进行了研究。结果表明： 在宁夏, 该虫2年发生1代, 以幼虫在被害油蒿根部越冬; 老熟幼虫于5月中旬从受害根部钻出, 在周围的沙土里结茧化蛹, 蛹期平均19.5±3.5 d; 成虫始见于6月初, 终见于8月末, 期间经历3次羽化高峰, 分别为6, 7, 8月的上旬。成虫羽化主要在14:00-17:00, 整个过程持续30~45 min; 羽化当日即可交配, 交配时间为20:00-21:00, 高峰期为20:30左右; 雄虫有2次交尾现象。雄虫寿命2~3 d, 雌虫寿命1~3 d, 极少4 d。雌雄性比约为1∶2.16。卵初见于6月中旬, 初孵幼虫初见于6月下旬。幼虫常单独危害, 且具有转移危害的习性, 蛀食坑道不规则。5-9月, 油蒿受害率为11%~44%, 平均24%, 株虫口密度为0.13头/株。幼虫对油蒿的树龄和地径有较明显的选择性, 主要危害1~4年生、 地径16~34 mm的油蒿。沙蒿木蠹蛾生物学特征的系统研究为其控制措施的制定提供了科学依据。     

Hydraulic architecture and water relations of Spartium junceum branches affected by a mycoplasm disease

Plant water relations, xylem anatomy and the hydraulic architecture of 1‐year‐old twigs of Spartium junceum, both healthy and affected by a phytoplasm disease, were studied. The disease causes twigs to be either shortened (witches broom disease, WBD) or flat (fasciate disease, FD). WBD twigs show a sevenfold increase in total leaf area, smaller and shorter xylem conduits, a higher stomatal conductance (g_l) and a decline of minimum leaf water potentials ( Ψ _l) below the turgor loss point. FD twigs had nearly twice the leaf area of the healthy controls as well as high g_l values and Ψ _l values below the turgor loss point. Moreover, significant differences between healthy and affected twigs in stem stomatal conductance (g_s) and in the total stem area were recorded. Affected twigs die back under drought stress, which is explained by a pronounced loss of hydraulic conductivity of the infected stems (40 and 60%) in FD and WBD as well as by the unfavourable ratio of weighted conduit radius ( Σ r⁴) to total surface area (A_t), so that the efficiency of the stem in supplying the whole transpiring area with water is strongly reduced.     

高温胁迫影响红掌生长发育的研究进展

红掌原产于南美洲热带雨林,其具有色彩艳丽的佛焰苞,在适宜的条件下可周年开花,是一种具有极高观赏价值的盆花和切花植物.夏季高温严重影响红掌的生长和观赏价值,增加了红掌的种植成本.对高温胁迫影响红掌外观形态、光合作用、细胞膜热稳定性、渗透调节物质、保护酶活性进行了讨论分析,对高温褪色机理及其应对措施进行了归纳总结,以期为进...     

朱顶红新品种DUS测试数量性状筛选与分级

利用70个朱顶红品种对12个数量性状进行了筛选及分级研究,并对5个数量性状的测量部位进行了研究。结果表明:所有性状均满足DUS测试要求,性状2由于区分能力弱不适于作为DUS测试性状。12个数量性状可进行3~9个连续分布的分级。花茎从下往上逐渐变细,但不同品种变细程度略有差异,在测量花茎中部的最大宽度时要求严格测量花茎的1/2处;不同茎上各数量性状测量值略有差异,除花茎长度和花梗长度外的性状差异不显著;同一花茎不同花间数量性状差异较小;同品种的花外花被片长度、宽度不存在显著差异;种球大小对数量性状有显著影响。     

澳门青洲山翻白叶树群落特征及物种多样性研究

根据样方调查结果,对澳门青洲山翻白叶树(Pterospermum heterophyllum)群落的种类组成、外貌、结构特征与动态及物种多样性进行分析.结果表明:(1)在1 600 m2样地中,有维管束植物47种,隶属于29科44属;对乔木层和灌木层主要物种的重要值以及频度分析结果显示,该群落是以翻白叶树为主的单优种群落,群落种类组成多样性和水平分布不均匀,其外貌终年常绿;对优势种种群的年龄结构分析显示,该种群处于增长状态;(2)整个群落的物种丰富度Margalef指数为13.72,Shannon-Wiener指数为1.15,Simpson指数为0.875,均匀度指数为0.34,该群落的层次格局为:灌木层>藤本层>乔木层>草本层;(3) 与其他5个不同类型地区森林群的物种多样性比较结果显示,澳门翻白叶树群落的物种多样性明显低于其他5个森林群落.     

Size‐correlated morpho‐physiology of the aroid vine Rhodospatha oblongata along a vertical gradient in a Brazilian rain forest

In this work, we analyse morpho‐physiological modifications presented during the allomorphic growth of the aroid vine Rhodospatha oblongata Poepp throughout its ascent into the forest canopy. We test the hypothesis that morphological modifications in the root, shoot and leaf are followed by a gradual improvement of the xylem vascular system in order to increase water acquisition and transport as body size increases. The characterisation of these structural modifications was based on 30–35 specimens divided into six size classes. The dimensions of shoots, leaves and roots were quantified and qualified. The transition from the terrestrial to the epiphytic phase was followed by a simultaneous increase of leaf number and lamina area, together with increased length and diameter of the petiole. Furthermore, as the plant grows, the shoot internodes become shorter and thicker. However, occurrence of aerial roots is the most important characteristic in the ascending phase. In taller individuals, the increase in number of roots with wider xylem vessels guarantees an increased theoretical xylem hydraulic conductance for this growth phase. Along an acropetal direction of the same shoot, the diameter of xylem vessels increased, while the number of vessels per stele area decreased, in contrast with such allometric models as that of West, Brown and Enquist, showing that xylem vessel number and diameter taper in a reverse manner along the same direction. Such structural changes of R. oblongata allow improved foraging for light and water, facilitating the survival of bigger‐sized plants of this vine in the canopy.     

一多重耐药单增李斯特菌株的生长特性及毒力分析

为了解单增李斯特菌株耐药后可能发生的生物学变化,以哈市生肉中分离到的1株对17种抗生素耐受的单增李斯特菌株L.M.B8为研究对象,对其生长及毒力特性进行研究。结果显示,L.M.B8的生长及毒力特性均与标准菌株有明显差异。在NaC l浓度为0.5%~5%、pH值为4.0~10.0及温度为20~45℃范围内,L.M.B8的生长速度均明显高于标准菌株。L.M.B8对高浓度盐的敏感性高于标准菌株,且对温度的适应能力强于标准菌株。从生长曲线看,L.M.B8的对数生长期与稳定期均较标准菌株提前2~3 h,且其稳定期较标准菌株明显缩短。L.M.B8小鼠腹腔注射半数致死量（LD50）较标准菌株明显降低。该研究为进一步探讨单增李斯特菌的耐药性与其他生物学特性的相关性奠定基础。     

大豆属Soja亚属种皮微形态特征的研究

采用扫描电镜对大豆属Soja亚属植物的种皮微形态特征进行了系统研究。结果表明,该亚属植物种皮微形态特征在种的水平上具有一定的分类学意义。     

儿童隐球菌性脑膜炎临床分析

目的分析并讨论儿童隐球菌性脑膜炎的临床特点、诊断及治疗方法等。方法回顾性分析上海长征医院皮肤科在1993年3月至2008年6月间16例经病原学确诊的隐球菌性脑膜炎患儿临床资料。结果患儿平均年龄7．25岁（2～15岁）,男女比例2．2：1,主要症状包括头痛（87．5％）、发热（81．25％）、恶心呕吐（75％）等,10例颅内压升高。确诊依据脑脊液真菌涂片、培养或隐球菌抗原检查。治疗采用两性霉素B和（或）两性霉素B脂质体静滴,5一氟胞嘧啶口服,辅以两性霉素B鞘内注射,联合氟康唑、伊曲康唑等药物治疗。16例患儿痊愈9例,病情明显好转5例,死亡2例。结论儿童隐球菌性脑膜炎起病缓慢,临床症状缺乏特异性,对疑有中枢神经系统感染性疾病时,应及早行脑脊液检查,并反复多次检查、联合检查以确定诊断,减少误诊、漏诊。早期诊断和及时、系统、足量、长程的抗真菌治疗是提高治愈率和患儿生存质量的关键。