资源交互斑块性生境中两种不同分枝型匍匐茎植物的克隆内分工

以青藏高原和四川盆地过渡带两种不同分枝型匍匐茎植物野草莓 (Fragaria vesca)和过路黄 (Lysimachia christinae)为对象 ,研究它们在高光照低养分斑块和低光照高养分斑块组成的资源交互斑块性生境中的克隆内分工。结果显示 ,与资源的空间同质性处理 (I)和 (II)相比 ,资源的空间异质性处理 (III)和 (IV)中野草莓和过落黄的近端、远端和整个克隆片段的生物量和分株数均获得显著增加。生长在低光高养条件下的远端分株 ,若与高光低养的近端分株相连 ,相比连接到低光高养的近端分株 ,它们分配更多的生物量到地下部分 ;生长在高光低养条件下的远端分株 ,若与低光高养的近端分株相连 ,相比连接到高光低养的近端分株 ,它们分配更多的生物量到地上部分 ;生长在高光低养条件下的近端分株 ,若与低光高养的远端分株相连 ,相比连接到高光低养的远端分株 ,它们分配更多的生物量到地上部分。实验结果表明 ,资源交互斑块性生境中野草莓和过路黄均发生了克隆内分工。通过克隆内分工 ,克隆植物能有效的利用异质性分布的资源 ,缓解资源交互斑块性分布对克隆植物生长的不利影响     

祁连山不同植被类型土壤碳贮量和碳通量

采用野外调查测定、野外定位观测和室内分析相结合的方法,在植被类型变化较大林区,选择邻近相同海拔、坡向和土壤类型的天然林(青海云杉林、祁连圆柏林、高山灌丛林)、人工林(13年生华北落叶松林)、牧坡草地和农田等植被类型土壤为研究对象,研究了祁连山不同植被类型的土壤碳动态.结果表明:天然林、牧坡草地、农田和人工林的土壤有机碳含量分别为59.45～84.7、78.30、13.51和43.25 g·kg-1,平均土壤有机碳密度分别为15.96～19.95、17.74、10.63和15.97 kg·m-2,土壤有机碳平均周转时间分别为27～36、25、23和33 a;不同植被类型土壤CO2通量依次为青海云杉林584.03 g C·m-2·a-1,祁连圆柏林517.63 g C·m-1·a-1,高山灌丛林601.00 g C·m-2·a-1,牧坡草地796.89 g C·m-2·a-1,农田281.75 g C·m-1·a-1,人工林569.92 g C·m-2·a-1;同一植被类型中,土壤有机碳含量和土壤碳密度随土壤深度增加而降低,而土壤有机碳周转时间则随深度增加而增大.     

Testing DNA barcoding in closely related groups of Lysimachia L. (Myrsinaceae)

It has been suggested that rbcL and matK are the core barcodes in plants, but they are not powerful enough to distinguish between closely related plant groups. Additional barcodes need to be evaluated to improve the level of discrimination between plant species. Because of their well-studied taxonomy and extreme diversity, we used Chinese Lysimachia (Myrsinaceae) species to test the performance of core barcodes (rbcL and matK) and two additional candidate barcodes (trnH-psbA and the nuclear ribosomal ITS); 97 accessions from four subgenus representing 34 putative Lysimachia species were included in this study. And many closely related species pairs in subgen. Lysimachia were covered to detect their discriminatory power. The inefficiency of rbcL and matK alone or combined in closely related plant groups was validated in this study. TrnH-psbA combined with rbcL + matK did not yet perform well in Lysimachia groups. In contrast, ITS, alone or combined with rbcL and/or matK, revealed high resolving ability in Lysimachia. We support ITS as a supplementary barcode on the basis of core barcode rbcL and matK. Besides, this study also illustrates several mistakes or underlying evolutionary events in Lysimachia detected by DNA barcoding.     

基于ITS序列探讨珍珠菜属过路黄组的系统关系

测定了紫脉过路黄、临时救和过路黄的nrDNA ITS序列,并分析了珍珠菜属过路黄组17个物种的遗传距离及亲缘关系。结果表明,过路黄组植物的ITS序列长度在620～628间,一致性高达90.59%,种间遗传距离为0.002～0.199。系统发育树表明:(1)紫脉过路黄、临时救和小茄亲缘关系较近;(2)大叶过路黄、落地梅和过路黄亲缘关系较近;(3)山萝过路黄、贯叶过路黄、管茎过路黄、叶头过路黄、峨眉过路黄及三角叶过路黄亲缘关系较近。ITS序列分析结果为组内植物的鉴定、分类及系统进化提供了新的参考。     

珍珠菜属植物种皮微形态特征及其系统学意义

利用光学显微镜和扫描电镜对11种珍珠菜属植物种皮微形态特征进行了研究。根据种皮微形态特征,可以明显的划分为两种类型,即黑腺珍珠菜型和金爪儿型。珍珠菜亚属的7种植物均属于黑腺珍珠菜型,黄连花亚属的4种植物均属于金爪儿型。种皮微形态特征支持以雄蕊群的构造为主要依据的属下分类系统,在亚属级水平具有重要的分类学意义。     

龙胜香草的名实订正

近年发表的报春花科Primulaceae龙胜香草Lysimachia longshengensis G. Z. Li &; S. C. Tang实为茄科Solanaceae单花红丝线Lycianthes lysimachioides (Wall.) Bitter之同物异名,故予以归并。     

珍珠菜属植物叶表皮纹饰特征及其系统学意义

利用光学显微镜和扫描电镜对21种珍珠菜属植物叶表皮纹饰特征进行了研究。根据叶表皮外壁纹饰特征,可以明显的划分为两种类型,即黑腺珍珠菜型和细梗香草型。这两种类型与以雄蕊群的构造为主要依据的属下分类系统的对应关系不密切,表明叶表皮纹饰特征在亚属级水平上分类学意义不大。但该属植物叶腺体的有无,颜色和分布以及叶表皮纹饰特征在种内相当稳定,种间差异较大,在种级水平上具有重要的分类学意义。     

Feeding ofScardinius acarnanicus Stephanidis, 1939 (Pisces: Cyprinidae) from Lakes Lysimachia and Trichonis, Greece

The feeding of the endemic freshwater fish Scardinius acarnanicus Stephanidis, 1939 has been studied from the content of its intestine and from the results of feeding experiments in the laboratory. This species appears to be phytoplanktophagous when young, whereas as an adult, it becomes macrophytophagous. No difference was observed in the diet of males and females.     

Canopy structure and leaf nitrogen distribution in a stand of Lysimachia vulgaris L. as influenced by stand density

Summary A hypothesis that a dense stand should develop a less uniform distribution of leaf nitrogen through the canopy than an open stand to increase total canopy photosynthesis was tested with experimentally established stands of Lysimachia vulgaris L. The effect of stand density on spatial variation of photon flux density, leaf nitrogen and specific leaf weight within the canopy was examined. Stand density had little effect on the value of the light extinction coefficient, but strongly affected the distribution of leaf nitrogen per unit area within a canopy. The open stand had more uniform distribution of leaf nitrogen than the dense stand. However, different light climates between stands explained only part of the variation of leaf nitrogen in the canopy. The specific leaf weight in the canopy increased with increasing relative photon flux density and with decreasing nitrogen concentration.     

Change in spatial distribution patterns of a biennial plant between growth stages and generations in a patchy habitat

BACKGROUND AND AIMS: The aim of the study was to evaluate factors causing change in spatial distribution patterns of plants between growth stages and generations for a monocarpic biennial plant, Lysimachia rubida. It was assumed that habitat heterogeneity was a primary factor determining spatial patterns of plants, and a randomization procedure was developed for testing the null hypothesis that only spatial association with ground surface conditions determined spatial patterns of plants. METHODS: A 5-year demographic census was conducted on an open dry habitat that was heterogeneous with regard to the ground surface conditions. KEY RESULTS: There was significant habitat association in that plants at vegetative and reproductive stages were denser in areas with smaller gravel than with larger gravel. Point process analyses rejected the null hypothesis of the spatial association with ground surface conditions. CONCLUSIONS: The results suggest that other factors, such as patchy seed dispersal, secondary dispersal of the seeds and life-history variation at various spatial scales, also affected spatial patterns of individuals in a population of L. rubida. Spatial structures and dynamics of a local population in a patchy habitat represent various performances of plants within patches and seed dispersal within a patch and beyond the patch.