First-generation transgenic plants and statistics

The statistical analyses of populations of first-generation transgenic plants are commonly based on mean and variance and generally require a test of normality. Since in many cases the assumptions of normality are not met, analyses can result in erroneous conclusions. Transformation of data to normality, the use of other distributions, or distribution-free statistical tests should then be used to obtain valid conclusions from these populations.     

New insights into the population biology of endoparasitic Rafflesiaceae

Parasitic plants demonstrate a diversity of growth strategies, life histories, and developmental and physiological characteristics. Most research to date has focused on a narrow range of parasitic taxa, particularly in the Orobanchaceae, while the other independent origins of parasitism have largely gone unstudied. One type of parasite that has received relatively little attention are the endophytic parasites, which have a fascinating growth strategy where the parasite is embedded within the host tissue, with the flower the only externally visibly plant part. Endophytic growth makes it challenging to understand basic aspects of species biology, such as the size of a given parasite, the number of parasites per host, and the genetic diversity of populations. Recent studies by Barkman et al. (2017) and Pelser et al. (2017) have used microsatellite genotyping to investigate the population biology of endoparasitic Rafflesiaceae species in Asia. They show the potential for extensive parasite spread within a host vine and the strong partitioning of genetic diversity by host. These species are also shown to have an outcrossing mating system. However, these studies suggest different reproductive strategies, one supporting monoecy and one suggesting dioecy. Overall, these studies partly “lift the lid” on the cryptic biology of Rafflesia and the Rafflesiaceae and open the door for future comparative studies between endophytic and free-living parasitic plants.     

Assessment of biological activities of chitosan Schiff base tagged with medicinal plants

A chitosan Schiff base with an aromatic aldehyde was synthesized and characterized by FTIR and NMR spectroscopies. Furthermore, the degree of substitution was calculated based on the ratios of the area of the proton of the imine (A_imine) and the area of the peak of the proton of the pyranose ring (A_H-2). The antimicrobial activities were determined against bacterial and fungal strains, as well as multiple drug-resistant (MDR) bacteria. The chitosan Schiff base was also tagged with medicinal plants, for example, Curcuma longa, Peganum harmala, Lepidium sativam, and cruciferous vegetables, and the biological activities determined against pathogenic bacterial and fungal strains. The chitosan Schiff base showed maximum zone of inhibition of 22 mm against Staphylococcus aureus with a minimum zone of inhibition of 15 mm against Bacillus cereus. The chitosan Schiff base was fused with C longa, isothiocyanates and a combined mixture of P harmala and L sativam that has shown activities against Escherichia coli with a zone of inhibition of 28, 24, and 30 mm, respectively. The Schiff base of chitosan fused with medicinal plants also showed significant inhibitory activities against MDR bacteria.     

吕梁山森林群落草本层植物物种多样性的空间格局及其对模拟增温的响应

为研究气候变暖背景下森林群落草本层植物物种多样性对温度升高的响应及其随海拔、纬度的空间分布格局,按照纬度梯度选择吕梁山系北段的管涔山和南段的五鹿山为研究区,并在每个山地的不同海拔梯度(高、中、低)分别设置对照(CK)、低度增温(OTC1)和高度增温(OTC2) 3种试验样地。于2017年植被生长季对植物多度、频度、盖度、高度进行调查,计算物种多样性指数(Simpson指数、Shannon指数、Pielou指数、Patrick指数)。结果表明:(1)吕梁山森林群落草本层植物物种多样性随海拔呈"v型"变化格局,即在中间海拔梯度处最低,且海拔梯度对各多样性指数的影响均达到极显著水平(P0.01)。(2)物种多样性随纬度升高呈递增趋势(P0.05),即较高纬度山地具有较高的物种多样性。(3)物种多样性随温度升高整体呈递减趋势(P0.05),即温度升高可抑制林下草本层植物物种多样性。(4)在增温处理下,五鹿山草本植物的Simpson指数、Shannon指数和Patrick指数呈递减趋势,Pielou指数先降低后升高;管涔山草本植物的Simpson指数、Shannon指数和Pielou指数先增加后减小,Patrick指数呈递增趋势。整体来说,在吕梁山较低海拔,持续增温会使物种多样性降低;在中等海拔,物种多样性随温度升高呈现先下降后上升的变化趋势;在较高海拔,适度增温可提高物种多样性,持续增温则抑制多样性。因此,增温对吕梁山森林群落草本植物物种多样性的影响随海拔升高整体呈下降趋势。     

福建省近三年(2015～2017年)新增维管束植物种类

通过文献检索,统计分析2015～2017年间文献报道的福建省境内新发现的维管束植物,包括新种11种(隶属5科)和新记录种80种(隶属35科)。至此,福建维管束植物达252科1643属5064种。     

紫茎泽兰叶片水浸液对蚕豆的化感效应

外来入侵植物可以通过淋溶、自然挥发、根系分泌和植株凋落物分解等途径向周围环境释放化感物质,抑制伴生植物的生长、发育。该研究以不同浓度紫茎泽兰(Eupatorium adenophorum)叶片水浸液处理蚕豆(Vicia faba)种子,研究紫茎泽兰叶片水浸液对蚕豆根尖细胞微核、染色体畸变、细胞凋亡、蚕豆幼苗叶片叶绿素和N含量、光合生理特性、生物量的影响。结果表明:(1)紫茎泽兰叶片水浸液处理显著抑制蚕豆根尖的伸长和细胞的有丝分裂,并诱导蚕豆根尖细胞染色体畸变和细胞微核的产生,有丝分裂指数随着叶片水浸液浓度增加而减小,根尖细胞微核率随叶片水浸液浓度增加而增大,高浓度叶片水浸液处理对蚕豆根尖细胞的凋亡及坏死有明显影响。(2)紫茎泽兰叶片水浸液处理引起蚕豆幼苗叶片的叶绿素和N含量显著降低,并导致蚕豆幼苗最大净光合速率和生物量的显著下降。总之,紫茎泽兰叶片水浸液可能引起蚕豆根尖的氧化损伤和抑制根尖的伸长,且叶片水浸液的抑制作用呈现一定的剂量效应。紫茎泽兰叶片水浸液对蚕豆根尖的损伤和抑制作用可能影响了植株对氮素的吸收,进而对蚕豆幼苗光合生理表现以及生物量积累产生显著负面效应。     

包头地区野生种子植物区系组成及特征研究

通过对包头地区野生种子植物区系进行调查、统计、整理,从科、属、种3个分类等级上对其区系地理成分、生活型、水分生态类型分别进行分析,探讨该区植物区系的起源和演化,为保护和利用该区珍稀、特有物种及其生存环境提供依据。结果表明:(1)包头地区有野生种子植物71科、274属、595种,其中,裸子植物2科3属5种,被子植物69科271属590种,占内蒙古被子植物的全部科、属、种的62.28%、43.81%、27.78%。(2)从科、属组成来看,包头地区野生种子植物组成中单属科和寡属科(2~4)、单种属和寡种属(2~4)构成了该地区植物科、属的主体部分。(3)从地理成分来看,温带成分占绝对优势;生活型以草木植物为主,占79.83%;从水分生态类型看,中生植物是该区的主要成分,占55.62%,旱生植物在该区系中也占有相当比重,占36.98%,说明该地区水分条件较差,在气候区上属于半干旱地区。     

西藏色季拉山野生药用植物资源多样性及其保护与利用

该研究采取路线调查、样方套记录、野外标本采集鉴定以及查阅文献资料等方法,对色季拉山野生药用植物多样性进行了系统普查分析,为该区野生药用植物资源的保护、利用和系统研究提供科学依据。结果显示:(1)色季拉山共有野生药用植物104科350属647种,其中蕨类植物13科15属22种,裸子植物2科3属9种,被子植物89科332属616种。草本野生药用植物478种,占总种数的73.88%;木本植物169种,占总种数的26.12%;全草类、根与根茎类药用植物最多,分别占药用植物总种数的46.21%和30.14%。(2)含1~5种的单种科和寡种科为绝对多数,占色季拉山野生药用植物总科数的72.11%,但仅占药用植物总种数的22.57%;而含种数最多的7科,只占总科数的6.73%,却共含255种之多,占总种数的39.41%,对色季拉山药用植物资源的构建起主导作用。(3)含有1个种的属最多,占总属数的64.00%,色季拉山药用植物没有明显优势的大属,表明属的构成较为复杂多样。(4)清热是色季拉山药用植物的主要功效,共有260种清热药用植物,占药用植物总种数的40.19%。(5)民族药用植物83科249属360种,占色季拉山野生药用植物总种数的55.64%。其中,藏药植物在民族药用植物中所占比例最大,共有63科156属235种,占民族药用植物总种数65.28%。研究表明,色季拉山野生药用植物种类多样性较高,药用植物生活型、部位、药效、民族用药类型丰富,但部分珍稀濒危资源如云南红景天、天麻、西藏八角莲等个体数量极少,建议建立专门的保护区,加强对野生药用植物资源及其原生境的保护,并加强人工繁育研究,针对资源储量制定适度合理的采摘利用量,以期实现野生药用植物资源的可持续利用。