Abstract:Based on the spot investigation, taking the height and ground diameter data as the basis, according to the age pyramid and the fitting equation of age structure, the age structure characteristics, growth status and development trend of the three typical populations of Kumtage desert were studied. The results showed that the age structure of H. ammodendron population was inverted “J” shape curve, and the population was currently in rising stage and was stability. The growth was limited because of their relatively small seedlings number. The age structure of T. taklamakanensis population showed a "bell" shape curve, and it showed similar stabile population characteristics. Bing of the very small number of seedling and the larger proportion of middle age class plants, the development of the population will tend to decline. The age structure of P. euphratica Oliv population has a certain peculiarities and showed a reverse "S" curves. The proportion quantity of middle class and older class plants maintained certain stability, and the large quantity of the small class plant make population has increasing potential. Their own age structure characteristics of three typical populations made them face the different degree threat of survival. So it was necessary to take different protection measures to maintain the population structure's stability and development.

Abstract:Pot experiments were carried out to study the effects of NaCl stress on the characteristics of photosynthesis and chlorophyll fluorescence in Portulaca oleracea L. Eight different concentrations of NaCl were applied: 0, 25, 50, 75, 100, 150, 200, 250 mmol?L-1. The results showed as follows : The plant fresh weights and heights of seedlings had no difference with the control when the concentration of NaCl was 25mmol?L-1, but decreased with increasing NaCl concentration when the NaCl concentration was above 25 mmol?L-1. When stressed by NaCl, inhibition was the first biomass, then followed by plant height. With increasing NaCl concentration, net photosynthetic rate (Pn) decreased, intracellular CO2(Ci) increased, and the magnitude of changes of Pn and Ci compared with the control increased with increasing NaCl concentration. Minimal fluorescence (Fo) , maximum fluorescence (Fm) , variable fluorescence (Fv) , stable fluorescence (Fs) , difference between Fs and Fo (△Fo) , PSⅡ potential fluorescence efficiency (Fv/Fo), PSⅡmaximum fluorescence efficiency (Fv/Fm) and photochemical quench (qP) of seedlings all decreased when stressed by NaCl, while NPQ increased. And at low concentrations NaCl (0-50 mmol?L-1) stress, the fluorescence parameters decreased less than other high concentrations of NaCl stress. So Portulaca oleracea L. was injured by photo-inhibition on NaCl stress, and at low concentrations, plant applied more light energy to photochemical reaction to maintain a high net photosynthetic rate, the degree of photo-inhibition was lower, therefor, NaCl stress had little effect on growth.

Abstract:A new form of Hepatica henryi (Oliv.) Steward, H. henryi Steward f. pleniflora X.D.Li et J.Q. Li are described. The new form differs from H. henryi Steward in flower pleiopetalous.

Abstract:Blechnidium is reported as a new record genus of pteridophytes in Guizhou province, China. It is a monotypic genus of Blechnaceae, with only one species, namely Blechnidium melanopus（Hook.）Moore. This species is narrowly distribute and its quantity is limited. It discovered in Guizhou is much of significance for researching its phytogeography and floristics.

Abstract:The internal structure of mature Tuber indicum ascocarps were observed by means of scanning electron microscope. The result further confirmed that, the white veins covered on the cross section of mature T. indicum ascocarps were composed of sterile paraphysis, while the dark veins which were to be the gleba were the fertile hyphostroma intertwined and surrounded by paraphysis, these white and dark veins constituted the maze veins on the cross section of T. indicum ascocarps; the developing uniform asci surrounded by plenty of intertwined ascogenous hypha and paraphysis could be able to be observed in the gleba, forming a thickly dotted tiny honeycomb like structure; the ascospores distributed free in asci, densely ornamented with stings on the epispore of fully mature spores, slightly having a crook on the tip of sting. The size of ascospores in an ascus was related to the number of ascospores contained in this ascus, the more ascospores contained in an ascus, the smaller the ascospores would be. The internal anatomy structure observation of T. indicum ascocarps by means of scanning electron microscope in great detail can provide reliable and visualized accordance for classifying of Tuber and understanding the internal characteristics of Tuber ascocarps systematically, as well as forming the foundation for the psychological study of Tuber ascocarps.

Abstract:In order to analyzing the distribution pattern of seedlings of P. euphratica after river overflowing, Clark-Evans index was calculated for measuring the distribution pattern by using the nearest neighbor analysis method and tested the deviation of actual CE index from the 1 by using the standard normal distribution. The results indicated that: (1) In the quatrats of 3m?3m, seedlings of P. euphratica presented aggregated distribution after river overflowing for 0-1 year and 1-2 year, uniform distribution after river overflowing for 2-3 year, and random distribution after river overflowing for 4-5 year and 5-7 year. (2) With the growth of P. euphratica’s age, the special distribution pattern of seedlings of P. euphratica changed from aggregated distribution to uniform distribution and to random distribution finally in the quatrats of 3m?3m. (3) In the various sizes of quatrats of 2?2 m to 10?10 m, seedlings of P. euphratica presented random distribution after river overflowing for different year. And the test value of standard normal distribution show that the deviation of CE value of P. euphratica seedlings from 1 in the various sizes of quatrats were not significant. As the scale increase, the spatial distribution pattern of P. euphratica seedlings had no significant change, and they always presented random distribution pattern.

Abstract:The annual growth and development rhythms of wild Primula maximowiczii plants in Dongling Mountains, Beijing were investigated from 2008-2010,and the flower initiation and inflorescence development were observed by light microscope. The results were as follows: (1) The annual growth and development of P. maximowiczii plants fulfilled under relative cool environment (5℃-20℃, average day temperatures) from May to September, and could be divided into 7 stages, including sprouting phase, vegetable growth phase, blossom phase, fruitage phase, mature fruit phase ,flower differentiation phase and dormancy phase. The fruit developed from July to August which was in the hottest season. (2) Flower initiation of P. maximowiczii began in middle or late July and finished in early September, which lasted almost two months, and the whole process could be divided into four stages, including vegetative stage, inflorescence primordium differentiation stage, inflorescence formation stage and floret differentiation stage. The florets formed from the outside to the inside of an inflorescence. Pistil and stamen formed and developed from middle August to middle

Abstract:The morphology and distribution of leaf trichomes of Isodon rubescens were studied using light microscopy. Three morphologically distinct types of trichomes were observed on I. rubescens leaf surfaces: non-glandular, peltate and capitate glandular. The glandular and non-glandular trichomes were present on both the adaxial and abaxial surfaces. Peltate and capitate glandular trichomes comprised one basal cell, one or two stalk cells and one head. The head of mature peltate glandular trichomes generally consisted of four secretory cells while that of capitate glandular hairs was composed of two cells. Histochemical results indicate existence of flavnoids in both peltate and capitate glandular trichomes. In addition, terpenoids, including monoterpenes, sesquiterpenes etc., exist in peltate glandular trichomes. Peltate glandular trichomes are probably only site of oridonin accumulation, however, this need direct proof to clarify. High density of peltate trichomes might be considered as an important selection character for the screening of I. rubescens with rich content of oridonin．

Abstract:With the methods of artificial cultivation and paraffin technology, It was observed that the morphogenesis of antheridium in Onoclea sensibilis and the multiformity of growing location. It is the first reported that the archegonium of overripe gametophyte shriveled and then disappeared, but the antheridium is normal, and the morphogenesis of the rachis contains protuberance, hollow and layering. The growing locations of antheridiums are different. For example, some are growth in the outer surface of the rachis or immersed in the rachis, some are growth in the hollow inner surface of the rachis. The structures of antheridium are also various. This article disscussed that phylogenetic significance on the morphogenesis of antheridium in Onoclea sensibilis and the multiformity of growing location and supplied basic data for discussing the systemic evolution of related groups.

Abstract:In 2008-2009 years, high-yielding cultivars 2000-75 and Jihong9812, and low-yielding cultivars Hongbao1 and Wanxuan1 adopted in the summer-sowing areas of adzuki bean, to investigation of root, growth index, antioxidative enzyme, soluble protein contents from the flowering stage to maturing stage,In order to promulgate between the root system and the leaf senescence characteristic contacts. The result indicated that the root activity began to rise at the early flowering stage,peaked at the peak flowering and pods formation stage and then rapidly declined, but the root activity began to decline later than the leaf activity. After flowing, the relationship of the root activity with the antioxidative enzyme (SOD and CAT) activity, the content of chlorophyll and soluble protein and photosynthetic rate of start leaves was positive; with their membrane lipid peroxidation product MDA was negative. Compared with low-yield varieties, high-yield varieties maintained higher contents of root activity, chlorophyll contents, Pn and SOD, CAT in the late stages, indicating that delaying or slowing down the leaf senescence plays an important role on yield.

Abstract:Aromatic rice; habitat; variety; soluble protein; content