Based on various reports both in print and online, 533 species have been selected as invasive species or potential invasive plants from North America. In order to better understand their invasive nature, the primary data on these invasive or potential invasive plants in North America are reported, including the composition of plant taxa, their habits, invasive origin, introduced time, meanings of introduction, most invasive habitats, invasive grades, and distribution in each states/provinces of North America.
Leafy spurge (Euphorbia esula L., s. lato.) native to Eurasia is one of the most notorious invasive plant in North America. In order to fully understand the current situation well, details of taxonomy, biology, physiology, invasion, damage and loss, as well as various controls of leafy spurge have been reviewed here, and concise prospects and summary are also discussed, with more than 200 references cited as well.
Phylogenetic relationships and systematic positions of Diplaziopsis and Homalosorus were investigated by using two chloroplast DNA regions (rbcL and rps4+rps4trnS). All the members of these two genera, 25 species representing other related groups and three outgroups were included in the combined analyses of chloroplast DNA sequence data sets which are performed with Maximum Parsimony, Maximum Likelihood and Bayesian Inference methods. The topologies of gene trees revealed that: 1) Diplaziopsis and Homalosorus form a monophyletic group with high bootstrap value; 2) Diplaziopsis and Homalosorus are not nested in Athyriaceae; 3) Diplaziopsis and Homalosorus show a parallel phylogenetic relationship with Dryopteridaceae and Aspleniaceae. On the basis of combined DNA data sets analyses and morphological characters, Diplaziopsis and Homalosorus are proposed to be treated as a family with close relation to Aspleniaceae.
The section Sclerophyllon of Lepisorus from China was taxonomically revised based on herbarium specimen examinations, field observation of native populations, and literature surveys. It turns out the scales and paraphyses characters are quite uniform within this section. But the leaf shape and the position of sori are the most useful characters for species delimitation. As a result, five species and one variety were recognized from China. They are Lepisorus eilophyllus, Lloriformis, Lloriformis varstenistos, Lsublinearis, Lcespitosus and Lpseudonudus. Two published names were reduced to synonyms. Lxiphiopteris= Lloriformis and Llancifolius=Lsublinearis. Key to species, descriptions and distribution maps are provided in this paper, as well as comments on the most important morphological characters for species delimitation.
Fifteen characters were measured in 11 populations of Gnetum parvifolium in Fujian Province, including 1139 leaves from 116 plants. The diversity index is 19281 at species level and 17573 at population level. 9114% of all genetic variation is distributed within populations. UPGMA cluster analysis and Mantel test also support that there is a positive correlation (r=06216, P=00020<0005) between genetic distance and geographic distance. The population differentiation conforms to the isolationbydistance pattern.
By analysis of genetic diversity and population genetic structure in natural populations of Sinocalycanthus chinensis with intersimple sequence repeat(ISSR) technique, the sampling strategy were determined based on the gene capture curve of 95% allele captured. The results are as follows: 6 populations to be sampled, the sampling proportion should be 30% and the distance between the sampled individuals are best of 26 m above. After seeds sampling and conduction of Exsitu conservation, the genetic diversity of the offspring population were evaluated that it conserved the genetic diversity of the natural populations effectively. Therefore, the systemic sampling method of endangered plants for Exsitu conservation of genetic diversity were discussed.
The composition, physiognomy, structure and dynamics characteristic, species diversity of the Cinnamomum japonicum varchenii community were studied based on community investigation. The results showed that 71 species in 63 genera 46 families of vascular plants were recorded in 7 plots in total of 700 m2. The analysis on species important value showed that Cinnamomum japonicum varchenii, Celtis sinensis, Ficus erecta varbeecheyana, Machilus thunbergii are dominant species of the community. The physiognomy of the community is ever green all year around. The age structure of dominant populations showed that three out of four main populations of the community are increasing populations. The species diversity of the community is measured with the Margalef index of 99917, the ShannonWiener index of 30657, the Simpson index of 09007, and the evenness index of 07192. The diversity pattern from maximum to minimum is herb, arbor, shrub. Diversity comparison with 4 other different communities showed that the species diversity of Cinnamomum japonicum varchenii community is slightly lower.
Arabidopsis ein25, ein31 and ctr11 are mutants in key genes of ethylene signaling transduction pathway. ein25 is absolutely insensitive to ethylene, ein31 is partly insensitive to ethylene, while ctr11 is constitutive triple response mutant. The morphological observation and measurement showed the rosette growth, shoot biomass and leaf area under PEG stress were restrained more significant in ethylene insensitive mutants ein25 and ein31 than in Col0 and ctr11. From the results, we can conclude that ethylene signal plays a positive role in regulating Arabidopsis growth and morphology under PEG stress. We also determined the physiological status in Arabidopsis under PEG stress. It was indicated that ethylene signal could regulate the plant to reduce the water potential to keep the osmotic potential, resulting in retaining water and enhance the drought tolerance. In the response of ethylene signal to drought, there was more osmotic modulatory substance soluble sugar. And the substance synthesized to a high level in fine ethylene signal pathway plants under PEG stress. We can conclud that ethylene signal can positively mediate the plant to adapt drought stress.
In order to study physiological responses to the island plant Cinnamomum japonicum under low temperature stress, the relative electric conductivity, the content of MDA and the activity of CAT were determined under different low temperature treatments for the leaves of Cjaponicum in winter. The results showed that the relative electric conductivity increased, MDA content also increased, CAT showed “M”type changes trend with decreasing temperature.
Shanghai Chenshan Botanical Garden (CBGS) is a new one in the global botanical gardens system, which is focused on botanical research, plant collection and public education. In CBGB, there are more than three thousand of plant species and at least six thousand of cultivars were planted. Therefore, the diseases and pests are also in a large amount. Facing to so rich plants and the status of so many visitors, in order to control the disease without harm to both plants and visitors, the pollutionfree agricultural chemicals are necessary to be used in this garden. The using of nonpolluted agrichemicals is still the start in CBGS now. A planning was confirmed by horticulture department of CBGS. According to the planning, we gave a list of pollutionfree agricultural chemicals, including biological pesticide, mineralbased pesticide and organic synthesize pesticide. There are 30 kinds of nonpolluted agrichemicals were listed, fourteen of them are biological pesticide, two is mineralbased pesticide, while the other fourteen are organic synthesize pesticide.
