Geographical differences of leaf traits of the endangered plant Litsea coreana Levl.var.sinensis and its relationship with climate

Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.

Population dynamics and protection strategies of Litsea coreana Levl.var.sinensis with Guizhou Province in China as an example

Studying the dynamics of plant populations is crucial to the conservation and management of endangered plants.The diameter at breast height(DBH),tree height,crown width,and environmental factors of a total of 15 plots in five populations in Guizhou Province,China were measured in this study.The method of substituting diameter at breast height for age was used to divide the population into 7 age classes.The age structure,static life table,and relationship between the population characteristics and environmental factors of the Litsea coreana Levl.var.sinensis population were studied.Moreover,the time series model was used to predict the population dynamics.Results showed that the age structure of population in Zhengan County(Population ZA)had an inverted Jshape with abundant seedlings and insufficient middle-aged and elderly individuals.The age structures of populations in Daozhen County(Population DZ),Kaiyang County(KY),Meitan County(Population MT),and Xishui County(Population XS)were spindle-shaped with few young individuals and many middle-aged and elderly individuals.The mortality rate of each population fluctuated with the increase in age class,and the populations were extremely unstable.The survival curve was close to the Deevey III type,and the degree of deviation was related to the lack of young individuals.After the age stages II,IV,and VI,the number of aged plants in the different populations initially increased then decreased,and population stability was difficult to maintain.Redundancy analysis showed that the DBH,tree height and crown width of the population decreased with the increase of annual mean temperature,and the population density was restricted by soil nutrient conditions to a certain extent.The results of this work provide scientific basis for the conservation and sustainable utilization of natural populations of L.coreana var.sinensis in Guizhou Province,China.

毛豹皮樟的叶片DNA提取及其RAPD引物筛选

以毛豹皮樟叶片为材料,对其DNA提取方法和RAPD引物的筛选进行了研究。结果表明,采用改良SDS法从毛豹皮樟的老、幼叶片中都能提取到高质量的DNA,可以用于RAPD分析;从4组随机引物中筛选出了16个显示毛豹皮樟遗传差异的多态性引物。

老鹰茶白粉病罹病植株的生理生化研究

供试的不同老鹰茶品种被病原菌侵染后,叶片中叶绿素含量、光合速率和蒸腾速率均随着感病程度的加剧而明显地下降,感病品种下降幅度大于抗性品种;而丙二醛含量随着感病程度的加剧而明显上升,感病品种增加的幅度比抗性品种大。老鹰茶叶片中叶绿素含量与其光合速率有显著的正相关关系。

毛豹皮樟苗木对低温胁迫的生理响应

通过模拟自然降温研究了4个品种(6号、8号、12号、38号)毛豹皮樟苗木对寒害的生理响应的结果表明:叶片电导率、丙二醛和可溶性糖随着处理温度的下降逐渐上升;8号过氧化物酶活性随着温度的下降,活性逐渐上升,12号、6号在处理初期活性先有小幅度的降低,随后才逐渐上升,但38号却是随着温度的降低活性一直在下降;12号、38号过氧化氢酶活性在处理过程中一直上升,6号、8号则呈现先下降后上升的趋势;脯氨酸则在处理过程中呈现先上升后下降的趋势。通过主成分分析,根据综合值大小得出4个品种的抗寒性强弱为12号>6号>8号>38号。电导率、过氧化物酶、脯氨酸、可溶性糖与毛豹皮樟抗寒性相关系数分别为-0.998、0.993、0.824、0.950,经方差分析毛豹皮樟的CAT、POD活性及SS、MDA含量在处理温度及品种间都有显著性的差异,均可以作为毛豹皮樟抗寒性评价的指标。

毛豹皮樟组织培养过程中褐化控制研究

为降低毛豹皮樟组织培养过程中外植体的褐变程度,提高增殖系数,试验对其不同的外植体(顶芽、叶片、带腋芽的茎段)、不同的基本培养基和不同的抗褐化剂等进行了研究。结果表明,毛豹皮樟不同的外植体褐化率不同,其中带腋芽的茎段褐化率最低,30d时为72%;1/3MS基本培养基中的带腋芽茎段褐化率最低;维生素C与活性炭对外植体褐变均有较好的抑制作用,其中在1/3MS基本培养基中添加0.8g/L的活性炭时外植体褐化率最低,仅为12%,增殖系数为4.5。

老鹰茶挥发油提取工艺优化及其抑菌活性

采用水蒸气蒸馏法对老鹰茶挥发油进行提取,以挥发油得率为指标,运用单因素实验和正交实验法考察了提取时间、料液比和超声时间3个因素对老鹰茶出油率的影响,最佳提取工艺条件为:提取时间5 h,料液比1:12,超声时间60 min。验证实验表明,优选工艺条件稳定可行,在该条件下提取率为(0.29±0.03)%。运用滤纸片法评价了老鹰茶挥发油的抑菌活性,结果表明老鹰茶对大肠杆菌抑制效果最佳(11.86 mm±0.23 mm),其次是金黄色葡萄球菌、枯草杆菌及四联球菌。