-->Special Column: Rare and Endangered Plant and Extremely Small Populations

Protection priority evaluation of rare and endangered medicinal plants in Manling County of Tibet, China

2018/7/28 16:52:32

Combining plots and route method, the resources of wild medicinal plants in Manling County of Tibet,China, were investigated more comprehensively. Several indexes included list coefficient, deposit coefficient, endangered coefficient, genetic coefficient, valuable coefficient, conservation coefficient and breed coefficient were used to identify the protection priority sequences of the rare and endangered medicinal plants quantitatively. Moreover, the species composition, function and parts used diversity of these medicinal plants were analyzed. Totally, there are 97 species(occupying 30.70% of the total medicinal species), 72 genera(occupying 32.00% of the total medicinal genera)and 37 families(occupying 48.05% of the total medicinal families)should be given a priority protection. Out of the 97 medicinal species, 95 species, 69 genera, 35 families represent angiosperm and two species, two genera, two families represent gymnosperm. Among these rare and endangered medicinal species, eleven species in eleven genera and nine families are classified as the first-class protected medicinal plants, 27 species in 25 genera and 18 families are classified as the second-class protected plants, and 59 species in 46 genera and 28 families are classified as the third-class protected medicinal plants. For the functions of these 97 medicinal plants, there are more species used as heat-clearing(32 species, accounting for 32.99%)and tonicing medicine(20 species, accounting for 20.62%). Additionally, among these 97 plants, more species use underground stem(34 species, accounting for 35.05%)and entire plant(26 species, accounting for 26.80%)as medical parts. The conservation priority classes and endangered level vary from our research to the lists of endangered plants. Sinopodophyllum hexandrum has the highest value of extent coefficient as the first-class protected plant but belongs to third-class protected plant on the lists. In addition, endangered degree of seven species was found growing to high levels in Manling county. Finally, based on these analyses and wild investigation, we analyzed the endangered causes for these rare and endangered medicinal plants from internal and external factors. Then, we put forward some suggestions on conservation such as making protective measures according to the protection priority sequences, building reserve, carrying out scientific research and strengthen legislation. Our results may provide a data basis for making scientific protection measures and the sustainable utilization of medicinal plant resources in Manling County.

Population characteristics of rare and endangered Loropetalum subcordatum in Maolan Natural Reserve of Guizhou

2018/7/28 16:52:33

Loropetalum subcordatum(Hamamelidaceae)is one of rare and endangered species, and endemic species to China. The population structure is an element issue for its protection. The innovation of this paper was to analyzed population characteristics of L. subcordatum in Maolan Karst Natural Reserve, Guizhou Province and to provide countermeasure for protecting L. subcordatum. We investigated the population diameter structure, static life table and studied survival curve of L. subcordatum based on the survey. The results showed were as follows:(1)Proportion of the individual number of L. subcordatum was diameter Class Ⅳ(2.5 cm≤DBH<5 cm), which accounted for 27.0%, and the seedling bank accounted for 24.7%. Therefore, the population was stable with lots of seedling and young trees pool.(2)Diameter class Ⅱ(h>1.3 m, DBH<1 cm)and Class I(h<1.3 m)has the highest life expectancy. At Class V(5 cm≤DBH<7.5 cm), there was an inflection point of life expectancy. In Class I, Class Ⅱ, Class Ⅲ and Class IV, the life expectancy of L. subcordatum decreased with the age increasing. In Class VI, Class Ⅶ, Class Ⅷ and Class IX, the life expectancy of L. subcordatum was increased firstly and then decreased with the age increasing.(3)Class V had the highest mortality and disappeared rate, because of the environmental sieve especially water stress. The trend of mortality curve was consistent with disappeared rate curve and the curve was up and then slightly down with aging.(4)The survival curve was monotone decreased except for Class Ⅱ to Class Ⅲ(1 cm≤DBH<2.5 cm).(5)To protect the species more effectively, the best way is in-situ conservation(on-site maintenance). The medium diameter class of L. subcordatum needs more attention to tending. The L. subcordatum population in Maolan can have a better recovery potential, as long as continue to maintain the reforestation politics.

Anatomical structure characteristics of vegetative organs of endangered plant Horsfieldia hainanensis

2018/7/28 16:52:33

The anatomy structures of vegetative organs of Horsfieldia hainanensis were studied by paraffin-sectioning and optical microtechnique to explore its adaptability to environment. The results showed that the leaves of H. hainanensis belonged to typical bifacial leaf, leaf blade-midribs was well-developed and the middle part had differentiated into pith. There was cuticle on the outside of upper epidermis of leaf and one layer endodermis inside. There was no cuticle on the outside of lower epidermis, and the sunken stomata were bicyclical type distributed. There were 3-4 layer cells in palisade tissue and 4-6 layer cells in spongy tissue. In the primary structure of stem, the epidermis was slightly keratinized, and the vascular bundle was ectophloic type. The 8-10 primary vascular bundles arranged around the pith were round. In the secondary structure of stem, the outer cuticle of epidermis was thickened, vascular bundles were closely arranged into rings, the secondary phloem and secondary xylem were developed, and there were 3-5 layer cells in cambium. In the primary structure of the root, the outer walls of epidermal cells were thickened. The exodermis cells were large and irregular in shape, with one layer endodermis in the inner layer. There was casparian strip in the endodermis. The primary xylem was polyarch, with a radial arrangement. In the secondary structure of root, there were 5-6 layer cells in cork layer. There was one layer of cork cambium in the inner cork layer and three layer cells in phelloderm. The vegetative organs of H. hainanensis had a certain shade and drought tolerance structure characteristics. Meanwhile, those anatomical characteristics were adaptable to the environment of high temperature and humidity in valleys of tropical rainforest.

Cutting propagation and regression planting of endangered plant Begonia gulinqingensis

LI Jingxiu, CUI Weihua, HU Xiaojian, KONG Fancai — 2018/7/28 16:52:33

We made a orthogonal test based on the theoretical basis of biostatistics, and listed four main factors of cutting slips level, cutting medium, growth hormone and shading rate affecting the rooting seedling rate of Begonia gulinqingensis. Each factor was set to three different levels, according to L₉(3⁴)orthogonal test, nine level combination of four factors orthogonal test at three level. Through L₉(3⁴)orthogonal test, we obtained the best solution for breeding leaf cutting of B. gulinqingensisendangered plant: keeping cutting bed temperature 22-28 ℃, cutting medium temperature 18-22 ℃, humidity 60%-75%, shading rate 70%-75%, as the cuttings in leaves and cutting medium in the perlites, 100 mg·L^-1 rhodofix to deal with cuttings, to give sufficient water during cutting management and its rooting rate 74%. Normally, cutting to adventitious roots needed 20-25 d and cutting to a new plant needed 70-85 d. The regenerated plants were planted in the natural distribution area be in progress reintroduction contrast test. The results showed that average preservation rate of native forest ecological group was 57.6%, the flowering rate 40%, the seed setting rate 36.6%, and seed regeneration rate 36.1%. Regression planting can reproduce the natural vegetation in the habitat of B. gulinqingensis, and it is a feasible method of ecological restoration.

Effects of hairy root configuration on growth of Psammosilene tunicoides

2018/7/28 16:52:33

The configuration of hairy roots is an important factor affecting its growth rate and biomass accumulation. In order to cultivate the hairy root of Psammosilene tunicoides in a large scale and to solve the problem of its resource shortage, hairy roots of Psammosilene tunicoides were sampled for exploring the effects of medium types, carbon source and carbon concentration on the growth of hairy roots. The results showed that the most suitable medium for growth of hairy roots was B5 + 30 g·L^-1 sucrose. Hairy roots are long, thick and strong, with large amount of the first and the second lateral roots and larger root surface area. Further examination was carried out in the mode of liquid suspension culture, and gained the similar conclusion with that of solid culture mode for the index of biomass of hairy roots. In this study, optimization of factors in the culture media facilitated the rapid growth and biomass accumulation of hairy roots.

Research advances on ecological characteristics of a rare and endangered plant Madhuca pasquieri

2018/7/28 16:52:33

As an important component of biodiversity, rare and endangered plants are one of the core contents of conservation biology. Madhuca pasquieri, a rare species currently, is regarded as VU(vulnerable)species in the IUCN Red List and listed as a kind of national key protected wild plants(Ⅱ)and wild plants of extremely small population. It is also a kind of rare oil tree species and precious timber species with high medicinal value. Due to the global climate change and the habitat fragmentation, it is rather important to study the current situation of M. pasquieri and formulate relevant conservation strategies. Based on the data of specimen records of herbariums, this paper mainly introduced the natural geographical distribution of M. pasquieri, compared population and community characteristics of the main distribution sites of M. pasquieri and systematically analyzed the current research and protection at domestic and overseas. The results are as follows:(1)With a wide range of vertical distribution from 200 to 1 400 m above, wild populations of M. pasquieri are mainly distributed in North Vietnam, South Guangxi, Southwest Guangdong and Southeast Yunnan.(2)The community of M. pasquieri forest has abundant species in tree layer, shrub layer, herb layer and vine layer. M. pasquieri is the dominant species in the main forest layer or important companion species in acid rain forest in Guangxi.(3)Mainly scattered in the warm and humid habitat, M. pasquieri is tolerant of drought and barren environments with krasnozem and laterite soil. It is concluded that the research of in situ and ex situ conservations, chemical composition and artificial cultivation of M. pasquieri have been carried out. However, these researches are still in primary stages. The following are hoped to be strengthened in the future: The supplement of the distribution information, field investigations with long-term experiment and the reintroduce of M. pasquieri based on in situ and ex situ conservations. Furthermore, molecular biology techniques are needed to strengthen the breeding, propagation and cultivation techniques of M. pasquieri, and can be actively developed for economic value and can be applied in landscaping.