Yan Xiufeng

Effects of water stress on berberine, jatrorrhizine and palmatine contents in amur corktree seedlings

Amur corktree (Phellodendron amurense) is one of the important associated species in broadleaved-Korean pine forests, and in the pharmaceutical resource plants of famous Chinese traditional medicine, named cortex phellodendri. Berberine, jatrorrhizine and palmatine are the main alkaloids to which high attention is paid by the researchers. In the present study, water stress treatments with four conditions, that is, mild drought, severe drought, waterlogging, and control (soil water potentials were controlled in the ranges of-40—-20 KPa,-80—-60 KPa, <-80 KPa and-20—0 KPa), were performed using the technique of root-sphere osmotic irrigation in a soil pond. The changes in the main medicinal compositions of berberine, jatrorrhizine and palmatine contents under different water conditions were discussed. As for the annual growing of amur corktree seedlings, mild drought was generally beneficial to the synthesis and accumulation of the three above-mentioned alkaloid contents. The three alkaloid contents did not show great changes under severe drought whereas those contents had significantly reduced under waterlogging compared with controls. Meanwhile, the growth of amur corktree seedlings was inhibited by the treatments of drought and waterlogging. The height, diameter and biomass of amur corktree seedlings were significantly lower than those of the control seedlings, which meant that the three alkaloid contents in a single seedling still kept the highest in control seedlings. Stem cortex was the medical part in Chinese traditional medicine and also kept the most abundant of the three alkaloid contents in amur corktree. Results indicated that short periods of mild drought could improve the berberine contents in the stem cortex, which might have reference value for the cultivation of amur corktree seedlings to obtain alkaloids.

Determination of contents of 10-Hydroxycamptothecin inCamptotheca acuminata by high-performance liquid chromatogram

The determination method of 10-hydroxycamptothecin inCamptotheca acuminatu fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrile-water (3:7, V:V), flow rate 1 mL·min−1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits ofC. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60°C for 50 minutes.

Effect of Planting Density on Plant Growth and Camptothecin Content of Camptotheca acuminata Seedlings

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25, 44 and 100 plants·m−2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem, and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area ofC. acuminata seedlings all showed highest values at the planting density of 25 plants·m−2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100 plants·m−2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m−2. It is concluded that for the purpose to get raw materials with more CPT fromC. acuminata, the optimal planting density ofC. acuminata seedlings should be designed as 25 plants·m−2.

Comparative study on population age structures betweenAdenophora lobophylla andA. potaninii

Comparing with an affinity and widespread speciesAdenophora potaninii, the age structures of A.lobophylla population, an endangered plant species were studied. 29 sample plots were investigated in the centered distribution area, Jinchuan county from altitude 2 300 m to 3 400 m. The main factors which influence the population age structures of A.lobophylla were analyzed. The principal characteristics of A.lobophylla populations are that the number of seedling and the density of population are much less than these of A.potaninii population. Below altitude of 2 700 m, the age structures of most A.lobophylla populations show the declining status, only above altitude of 2 700 m they are stable, while age structures of all populations of A.potaninii populations at corresponding altitude perform stable and developing features. The age structure patterns, relations between age (x) and number of individual (y) of stable populations of A.lobophylla can be expressed by equation: y =e(a-bx), and the longest life span is 25a. Whereas A.potaninii populations can be expressed by the equation: y =ax-b, and the longest life span of individual is 21a. The external factors, which constrain the extension of A.lobophylla population, are extreme environmental conditions such as serious drought, external disturbance and low temperature.

Effect of arbuscular mycorrhiza on the growth of Camptotheca acuminata seedlings

Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi (AMF), Acaulo spora mellea, Glomus diaphanum and Sclerocystis sinuosa. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.

Effect of shading treatment on stomatal behavior ofAdenophora lobophylla at different ages

The stomatal behavior ofAdenophora lobophylla of different age structures was studied in July 1995 in greenhouse of the Harbin Forest Farm of Northeast Forestry University by means of shading experiment. The effects of different shading treatments on the stomatal physiological character and ecological adaptation ofA. lobophylla of different ages were compared. The results showed that the morphological characters of annualA. lobophylla were more obvious than that of the perennial, but the stomatal density of annual was less than that of perennial. Growth of annualA. lobophylla was more sensitive to the change of environment than that of the perennial. The ecological adaptation of annual was weak, which was one of the main causes of endangered population.

Diurnal change of gas exchange of Rhodiola sachalinensis transplanted from different habitats in Changbai mountain.

Rhodiola sachalinensis growing in the different habitats, such as Xiaotianchi plot (altitude 1800 m), Tree line plot (altitude 2000 m) and Tianwenfeng plot (altitude 2325 m) of Changbai Mountain (northern slop) were transplanted to Harbin Experimental Farm for determining its gas exchange. The study results indicated that the diurnal changes of gas exchange ofRh. sachalinensis transplanted from different habitats were still different though the morphological appearance of the newly sprouted above-ground part had become more similar. For net photosynthesis rate (Pn), stomatal conductance (Gs) and apparent quantum yield (AQY), the diumal change curves ofRh. sachalinensis transplanted from the three plots were similar, but the data value were different. For the dark respiration rate (Rd), transpiration rate (Tr) and water use efficiency (WUE), diurnal change curves of the three plots were obviously different.

Relationship between stomatal behavior and characteristics of photosynthesis and transpiration ofAdenophora lobophylla andA. potaninii at different altitudes

The photosynthesis and transpiration characteristics ofAdenophora lobophylla andA. potaninii, as well as stomatal behavior such as stomatal size, stomatal density, stomatal open and stomatal conductivity were measured at different altitudes. The relationship between the photosynthesis and transpiration characteristics and the stomatal behavior was analysed by correlation coefficient and path coefficient analysis with altitude changes. The results showed that the influences of stomatal behavior were not evident on the photosynthesis and transpiration characteristics ofA. Lobophylla, but evident on that ofA. potaninii.