Abstract:A purification method combined with cellulase digestion and differential centri-fugation was found ot purify the pathogen from priwinkle plants infected with citrus yellow shoot,The solution consisting of O.1mol/LMgCl2,O.5 mol/L D-mannitol,O.6mol/L glycine was used as the medium for the isolation and purification.The results obtained in the present study showed that the yield of the pathogen purified was higher,and the external morphology,the transparency af wall-membrane structure and internal structure of the pathogen were better maintained.Meanwhile,the purification method gave consistent results in different replications.The purified pathogen of citrus yellow shoot obtained with the method mentioned abore was used as antigen to immunize mice for the preparation of ascitic fluid.It was shown that the antibodies in the fluid had specific response,The micro-precipitation titer was 1:640,the titer of ring surface agglutination reaction 1:8,and that of immunosorbent electron microscopy 1:320.NO reaction was observed in the agar gel double diffusion assay test.Controls all showed negative reaction.The isolated and purified pathogen was thus recognized to have biological activity of specific antigen.

Abstract:Investigating the fungal diseases of famous Chinese medical plant(Amomum vil-losum Lour.),we have fouud five kinds of diseases in Yang-Chun and Feng-kai Counties etc.,Guangdong Province.They are the seedling anthracnose caused by Colletotrichum zingiberls(Sundar.)Butler et Bisby.,the leaf anthracnose of adult plant by Colletotrichum gloeosporioides Penz.:the fruit rot caused by Rhizoctonia tolani Kuhn.,and another fruit rot by Fusarium sp..The most important desease it the leaf spot which causes serious damage and great loss in production of Amomum vilosum.According to its morphology,cultural characteristics and artificial inoculation,the pathogen of the leaf spot is considered to be a new genus(Gona-topyricularia Z.D.Jiang et P.K.Chi gen.nov.),the type species is G.amomi Z.D.Jiang et P.K.Chi sp.nov..Latin and Chinese diagnoses with reference to morphological photographs are given for the genus and the type species.

Abstract:A brown rot of straw mushroom(Volvariella volvacea)occurred commonly and caused serious damage in Guangdong province,Fujian province and Guangsi Autonomous Rigion.A pathogenic bacterium was isolated in this laboratory in 1985.Inoculation tests showed that the infected mycelium of the fungus stopped growing first and then rotted away,and the fruiting bodies turned yellowish brown to dark brown in color,then shrank in size and finally also rotted away.Based on the bacterium morphology,cultural charactristics,sresults of biochemical tests and serological test,the pathogenic bacterium was considered to be a Xanthomonas,sp,Further study on the identification of the species is in progress.

Abstract:The pollen morphology of 59 species belonging to 22 genera of Sterculiaceae in China was studied by LM and SEM.Based on the number,shape and position of the aperture as well as its ornamentation they may be grouped into twelve pollen types;1.Sterculia-type,2.Heritiera-type,3.Waltheria-type,4.Ree-vesia-type,6.Craigia-type,e.Ambroma-type,7.Byttneria-type,8.Dombeya-type,9.Pterospermum-type,10.Helicteres-type 11.Kleinhovia-type and 12.Eriolaena-type.According to the point of view of Palynology,the division of pollen types in Chinese Sterculiaceae is discussed in this paper.

Abstract:The climate of Guangdong Province is of a humid subtropical type with distinctive both dry and wet seasons and frenquent alterations between droughts and waterloggings during the vegetative period.This situation coupled with the inferior structure of the predominent red soil often puts fruit trees in extremes of water regimes.The respouses of fruit trees to the local ecological conditions are the shallowness of root distribution and rapid built-up of internal water stress duriug dry spells.The disorders caused by uufavourable water regimes may be exemplified as excessive fruit-drop,uudersized fruits,wilting in a sudden clear day after a long spell of rains,fruit cracking,offseason leaf-drop and etc."An exuberant canopy supported by a shallow root system" characteristic of the local fruit tress is in sharp contrast to that "an exuberant canopy arises from a deep root system" in the temperate zone.Therefore,studies on the water relations of fruit trees in this areas are of no little significance.

Abstract:The histological structures of the hypophyses of 50 adult Chinese buffalos were studied by sections in sagittal,transverse and horizontal planes.Four stainig methods were used;Haematoxylin and Eosin(H-E),Periodic Acid Schiff PAS),Orange G(OG)and PAS-OG.The pars distalis is well developed.lt is apparently divided into three zones.The PAS-positive basophils are mostly localized in the highly vascular rostral portion,forming a basophil zone while the OG-positiv acidophils in the candal portion forming an acidophil zone.Between these two zones is the mixed zone of basophils and acidophils.The cells are grouped in clusters and cords or in follicles.There are numerous sinusoid capillaries.The pars tuberalis completely surrounds the infundibular stem.It appears highly vascularized and consists of undifferen-tiatied cells each with a dark staining nucleus and a scant amount of cytoplasm,chromophobe cells and a few PAS-positive basophils.They are arranged in tnbules or in follicles.NO acidophils were found.The pars intermedia is well developed,completely or mostly surrounding the pars nervosa.It is lobulated and consists of basophils and chromophobe cells arranged in clusters and cords or in follicles,but the lobules are bordered by a single layer of basophilic columnar cells.The cone of Wulzen was not found.The pars nervosa of the Chinese buffalo is relatively small.The median eminence is thickened mainly in the anterior part.The strongly PAS-positive colloid was found in all parts of the adeno-hypophysis and neurohypophysis in the mature Chinese buffalo.Comparisons were made of the morphological features of various parts of the hypophysis,distribution of cells and the occurrence of colloid of the Chinese buffalo with those of the ox or other animals.

Abstract:This paper deals with the effect of controlled light on the morphology and his-tological structure of the testes in stud ganders during normal reproducdive period and nonreproductive period.The results show that there is a significant difference(P<0.01)in morphology and weight of the testes and spermiogenesis in the seimiferous tubules between the ganders illuminated with controlled natural light and the controt ganders during their non-reproductive period,but no significant difference during their early and surge breeding stage of the normal reprodutive periob.The relationships between the light value and the development of avian genital glands are also discussed.The objective of this study is to offer some useful data to the out-of-season production of geese in Guangdong province.

Abstract:Generally;the distribution of the poplars in the world is from temperated zone to middle subtripical zone,their compositions are rather pure and their constructions are rather simple.The appearance of poplar forest in Hainan Island is a new discovery and a new distribtion in the world.This research is a synecology on that poplar association.The Result has been found that it is a multispecies,multi-layers,tropical coniferous and broad-leaved mixed forest which the dominant is poplar,that its species composition is belong to 12 family,13 genus,16 species which most are tropical essen tial,as 13 species are tropical(81%),and that in the forest the relative density,relative dominance,relative frequency and the importance value index of the Populus qiondaoensis sociation are the first,and of the pinus lateri sociation are the second.These two species are the dominant and the snb-dorninant of the association.They are tall and straight.The former is 120cm in b.h.d.and the latter is 38m in height.Their single tree volume can approach about 16-17m3.From the result of this study,it is recommended to research and develope the topical poplar ecosystem.

Abstract:In this article,a study on the relationships between the beefwood(Casuarina equisetifolia)growth and the micronutrient B,Mo,Mn,Cu and Zn in the coastal sandy soil of Guangdong was made.The results showed that the B and Mo benefited the promoting growth and resisting disease pest;the Cu high concentration restrained the growing,others were not any role for the growing of beef-wood.

Abstract:The effect of the solar radiaation is hidden by the forest belt on rice field in the Peral River Dalta had been analysed.Which the main forest with west-East direction this effect is very little.So thet,the best direction design of the main forest belt in the peral River Dalta is West-East direction.