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1995  Vol. 13  No. 3

Abstract:
To establish excellent embryogenic suspension culture is the key step of protoplast culture of grasses. We describe a way of establishment and sustaination of embryogenic suspension culture with high plant regenerability of wheat. Fast growing ,fine dispersed embryogenic suspension cultures with high plant regenerability were established within 2 weeks when type Ⅱ embryogenic calli were cultured in an improved liquid MSmedium (SDL) with approximate 3 days doubling time; Ameliorated N6 liquid medium (NBDL) did not support embryogenic suspension cultures very seccessfully with approximate 5 days doubling time ; AAliquid medium was failed to support embryogenic suspension cultures of wheat. Plant regenerability of embryogenic suspension cultures was declined when they were cultured for a long period of time,but it was restored when the cultures were transplanted to solid NBDmedium previously for a short time and then transferred to liquid SDLmedium. We sustained the regenerability successfully by using this approach.
Abstract:
A taxonomic révision of the genus Saussurea in Hebei,Beijing and Tianjin is presented. 23 species from Hebei, Beijing and Tianjin are recognized, of which 4 species are recorded as new to the areas, 6 specific names are reduced as new synonyms and two mistakes of distribution in the genus are rectified.
Abstract:
1831 species of seed plants that belong to 742 genera in 157 families distribute in Jinggang Mountain, including 13 species in 12 genera of 7 families of gymnosperm. Among them, 990 species of woody plants belong to 304 genera of 91 families while 841 species of herbal plants belong to 420 genera in 66 families. The main points of the flora of spermatophytes in Jinggang Mountain such as geographical components, communications with others,major characteristics,history of the flora are discussed in this paper,one reason fot this study is to give people some reference information to make rational use of plant resource and protect biological diversity.
Abstract:
This paper deals with the floristic components,geographical distribution and ecological environments of the Pteridophyte in Shandong. The floristic relationships between Shandong and some other regions are also disscussed. The results show that: 1. The floristic elements are relatively not rich, however, the geographical elements are varied. All the 40 genera can be classified into 10 areal-types, mainly composed of the North Temperate(30.0%), the Pantropical(22.55%), and the Cosmopolitan(20.0%).The areal-types of temperate account for 42.5%, taking a predominant position, while those of tropic account for 37.5%. 2. Endemism is remarkable, 12 species of Pteridophyte, which make up 11.3% of the total numbers, are endemic to this province. 3. The geographical distribution is fairly uneven, The number of species are decreased from South to North and from East to West. 4. The similar quotents of Pteridophyte flora between Shandong and Liaoning, Beijing, Henan, Qinling, Japan, Hainan, Xizang are 46.4%, 45.3%, 41.2%, 26.0%, 24.8%,4.7%, 3.8% respectively in sequence order. This means that this flora is most similar to Liaoning, and then to Beijing and Henan.
Abstract:
Gap characteristics and regeneration in beech(Fagus engleriana)forests in Taiyangpin were studied. 10 gaps were observed. Gap covered 40.1% of total surveyed area of 5000m2, the average of gap size was 201m2. The reasons of gap formation were discussed. The component of regeneration of Fagus engleriana had a positive correlation with the size of gap. It was revealed that the regeneration of Fagus engleriana took place in the gap formed by the falling or death of one or several canopy trees. By means of gap regeneration, Fagus engleriana forests can maintain their stabilities of structure.
Abstract:
This paper deals with the structure and dynamics of Platycladus orientalis population at the forest area in loess plateau of northern Shaanxi Province. The results are as follows: 1. Platycladus orientalis is a pioneer species of the forest succession in this rigion. But the population at rocky steep slopes or ridges may develop into stationary community.2. The size structures are classified into seven types: initial growing;growing-stational;stational;declining;extremely declining;residual and disclimax types.3. The population density tends to decrease with the population and succession development,and ,has significant negative correlation with coverage of arbor layer,age of Platycladus orientalis population and moisture of soil.
Abstract:
Changes of biological metabolism were happened during the seed development of rapeseed. There were gradually increased in activities of glucose-6-phosphate dehydrogenase, isocitrate lyase, isocitrate dehydrogenase and succinate dehydrogenase. The activities of glucose-6-phosphate dehydrogenase and isocitrate lyase increased to maximum ,however,the activities of isocitrate dehydrogenase and succinate dehydrogenase increased slowly when oil synthesized rapidly. During whole developing stages of rapeseed, the glucose-6-phosphate dehydrogenase and isocitrate lyase in different strains with high oil content were more active than with low ones; on the contrary, isocitrate dehydrogenase and succinate dehydrogenase in strains with low oil content were more active than with high ones. The activities of four enzymes in hybrids were expressed between the range of parents.
Abstract:
In this experiment, the growth of seedlings and roots were obviously inhibited when seedlings of Phaseolus angularis and P. radiatus were exposed to 0─4℃for 1─2 weeks, but the growth of Glycine max (L.) Merr. had not completely been inhibited. The changes in PODand ATPase isozymes of roots have been observed when seedlings were exposed to 0─4 ℃ for 1─2 weeks. The relationship between inhibited growth of seedlings and changes of POD, ATPase isozymes in three crops which were cultured at low temperature (0─4℃)was obvious.
Abstract:
The present paper deals with a study on the growth, peroxidase activity changes and isoenzyme pattern of Asparagus officinalis L.callus cultured under five different light wavebands. The results show: Different light has different effect on callus growth (Blue and red light have considerable effect); Different light has different effect on peroxidase activity either; The change of peroxidase activity has positive correlation with the growth of callus.
Abstract:
As a transitional zone in natural geographic factors from west to east, and flora development and evolution from south to north, central China has been supposing as one of the key area in the study and conservation of biodiversity. However, heavy population stresses already made the ecosystems degraded, biodiversity lost at an alarming rate. Taiyangping locates in Shennongjia forest distrect, western Hubei Province in this zone. Comparing with others, it has not been disturbed by human being, so it is invaluable to biodiversity study. In the essay, we deal with the status of biodiversity basing on plant species, and forested ecosystems. After then, we pointed out strategies for the coexistence between biodiversity conservation and economic development.
Abstract:
(1)35 species and varieties of the genus Actinidia were collected and conserved. (2) 2 cultivars were chosen from the wild strainsof A. chinensis Planch., such as "Wuzhi-2", "Wuzhi-3". (3) The hybridization between A. chinensis and A . eriantha was studied. 3 ornamental strains were selected from the F1 progenies, such as "Chongban", "Mantianxing"and "Jiangshanjiao".