The authors observed Blue Sheep ( Pseudois nayaur) population in the Helan Mountain , Ningxia Province in November 1994 ,between J uly and Nevember 1995 ,respectively. It was found that the Blue Sheep preferred to elevation of 1800～2000 m in Helan Mountain. The Blue Sheep foraged primarily in the morning and at dusk. Of the 448 individuals observed ,the average herd size was 5. 5 individuals. The Blue Sheep were frequently seen in small herds of two to eight individuals (70. 8 %) . Of the 403 Blue Sheep classified by sex , the ration adult females to males was 1：1. 2 , and the ratio of adult females to young was 1 ：0. 44 ,the population showed a trend of increase. Hunting , human disturbance and livestocks were major threat against Blue Sheep’s lives.

The importance of utilizing acetolactate synthase (ALS) gene to create herbicide－resistant plant attracted the interest of plant molecular biologists. Understanding the structure , organization , function and the variation of ALS gene in agronomically important species is essential to transfer the resistance. ALS gene was demonstrated to be multigene family among Brassica species. The objectives of this study are (1) to reveal variation of ALS gene among cultivated B . rapa , B . oleracea , and B . napus ; (2) to determine how variation for ALS gene is distributed at the species , subspecies and accessions level ; (3) to evaluate the feasibility of utilizing genetic marker from ALS gene family to discriminate accessions of B . napus. Polymerase chain reaction (PCR) was employed to reach the three objectives. Extensive variation for ALS gene family exists among B rassica subspecies and accessions. The degree of genetic variation differed within different species. At the subspecies level , variation within B . oleracea was lower than that within B . napus , but higher than that within B . rapa. Significant variation was found among accessions of B . napus indicating that the ALS gene family may be used to discriminate among individual accessions.

Based on the types of threatened species put forward by International Union for Conservation of Nature and Natural Resources( IUCN) , the threatened aquatic higher plant species of China were classified into seven types as follows : two extinct ( Ex) , sixteen endangered ( E) , thirty one vulnerable (V) , twenty two rare (R) , forty four indeterminate ( I) , twenty one out of danger (O) and eleven external ( El) species. The factors affecting these threatened species were also discussed.

In this paper , protein electrophoresis was conducted to analyze the blood protein polymorphism of Diannan Small-eared Pig. Out of 32 genetic loci surveyed , six (AKP , CAT , ES , PA , 6PGD and TF) were found polymorphic , with mean heterozygosity ( H) being 0. 0712. The results indicated that the blood protein polymorphism of Diannan Small-eared Pig is high , and thus the Diannan Small-eared Pig is wealthy of genetic diversity at the protein level.

In 1995 , a new esterase phenotype was found in a population of Meloidogyne javanica infecting tobacco in Lunan County of Yunnan Province , and the Rf value is 0. 47 and 0. 59 respectively. Morphological characters and differential host test suggested that the population belongs to M. javanica. However , the esterase phenotype was found to be different from that of M. javanica reported so far to absent a band ( Rf = 0. 55) . The new esterase phenotype is here designated as J2 for M. javanica. The possibility of a subspecies identity to accommodate the population with the new esterase phenotype is discussed.

This paper reported sixteen bacterial strains isolated from fishes naturally infected by epidemic septicemia (including silver carp , bighead carp and common carp) . Of them , eight evidently caused disease , especially SC96-1-1 and SC96-2-4 caused deadly disease and the incidence is up to 100 % during 4～24 hours. All isolates were determined in growth , physiological characteristics and classification. The results showed that they shared following characteristics : gram-negative rod , motile , oxidase positive , V-P positive , glucose and mannitol fermentative , but not inositol fermentative , not urea decomposite. These features indicated that the pathogen of epidemic septicemia occurred in Beijing belonged to Aeromonas hydrophila. This result provides scientific basis for the prevention and cure of this infectious disease.

Nine cultivars belonging to four species and one hybrid of Allium commonly cultivated in China were analyzed by RAPD markers to determine their genetic relationship. Of the 20 decamer nucleotide primers screened , 11 showed consistent banding patterns and amplification and produced 102 bands with 68 polymorphic. The similar indices among the materials ranged from 0. 571 to 0. 947. A . fistulosum var. gigantum cv. Zhangqiu Welsh onion , A . fistulosum var. gigantum cv. Tianjin Wuyeqi Welsh onion , A . fistulosum var. caepitosum cv. Shanghai Spring onion and A . fistulosum var. caepitosum cv. Nanjing Winter onion (Spring onion) had the highest similar indices of 0. 947 and 0. 942 respectively. Relationship between the cultivars determined by UPGMA cluster analysis demonstrated Zhangqiu Welsh onion , Tianjin Wuyeqi Welsh onion , Shanghai Spring onion and Nanjing Winter onion were clustered together respectively. The two Welsh onion cultivars , two Spring onion cultivars and Welsh onion from Korea were clustered very closely. A . schoenoprasum and A . fistulosum var. viviparum were subclustered further in the group of A . fistulosum , including A . fistulosum , A . schoenoprasum , A . ascalonicum and A . cepa were clustered together. The hybrid of Zhangqiu Welsh onion ×A . cepa was clustered very closely with A . ascalonicum and A . cepa , but clustered with the group of A . fistulosum with the furthest linkage distance. A . ascalonicum and A . cepa could be included in the group of A . cepa. The taxonomy of A llium was discussed on the basis of RAPD markers.

There are 41 waterbird species in the Changzhou reservoir area. Of them , 38 species are grallatores. These waterbirds occur mainly in the river valley. An environmental assessment based on the habitats and ecological characteristics of waterbirds predicted that construction of the dam will make negative impacts on the grallatores. The habitats are divided into five types : (1) water surface of the river ; (2) sandbank and small islands ; (3) farm field along the river valley ; (4) ponds along the bank ; (5) small streams. The second type , sandbank and small island , will be lost almost completely , and hence the grallatores in this habitat will be seriously disturbed. The 30 wading bird species in this habitat will decrease to 12 species , and 96. 5 percent of the bird populations will decrease. The prediction analysis indicate , in the whole reservoir area , that five wading bird species will disappear when the dam is built . Of them ,Chinese Egret ( Egretta eulophotes) and Sacred Ibis ( Threskiornis aethiopicus) are state-protected bird species. The populations of 16 wading bird species will decrease to less than 20 percent ,and four species will decrease to 20～50 percent , five species to over 50 percent . Five wading bird species will be slightly influenced. Only one wading bird species will increase their populations. Due to the change of the habitat , a succession of waterbird community will take place with the number of species and populations of the grallatores decreasing and the natatores increasing. The critical endangered species White-eared Night Heron ( Gorsachius magnificus) is also impacted. It is suggested that a further survey on ecology of the species should be carried out so that an effective conservation measurement may be found.

The conservation of boidiversity is faced with two basic problems : how to determine biodiversity measurements and how to conserve biodiversity. Based on species concept , the traditional ways for biodiversity measurements are to determine different kinds of biodiversity indices by using ecological and geographical approaches. These measurements depend on the size of sample areas in investigations and all species are valued equally in taxonomy. The phylogenetic diversity measurements of biodiversity are based on the theories and methods of phylogenetics and genetics and can determine contribution of a species in a taxon to the taxic diversity . But this approach is too complicated and can be used in conservation only when phylogenetic and genetic data are much complete. It is suggested that combination of species viability approach and the phylogenetic diversity measurements will contribute to determining the priority of species and ecosystem conservation

Reconstruction of the evolutionary history of species based on the genetic and species diversity is one of the most important subjects in the current study of molecular evolution. If reliable phylogenies are produced , they will shed light on the sequence of evolutionary events , and help us to understand the mechanisms of evolution as well as the history of organisms. The goal in this paper is to give a brief introduction to several important issue in phylogeny inferring : the tree-building methods , data transformation , reliability of inferred tree , and several common used computer programs.

The widespread adoption of improved high-yield rice varieties , which in a large scale replaced traditional and local rice varieties , has resulted in a great genetic erosion of the cultivated rice genepool. This process has narrowed genetic background of the cultivated rice. As a result , modern rice varieties become vulnerable and can not stand the attack of new disease and insect pests , and the unfavorable changes of environments. Meanwhile , the long2term use of chemical pesticides and herbicides significantly deteriorated agricultural ecosystem. In order to change this vicious cycle of the rice ecosystem , it is very important and necessary to explore and utilize the genetic biodiversity in the rice genepool to broaden the genetic background of the cultivated rice. The rice genepool encompasses varieties of Asia rice and African rice , weedy rice , wild species of rice in the genus Oryz a , and species in the related genera of the tribe Oryzeae. These are the essential germplasm resources for the further improvement of cultivated rices. However , due to the change of agricultural patterns , rapid development of social economy , industrialization and urbanization , biodiversity of the rice genepool , including wild species of rice , is under threat . Many populations of wild Oryz a species have been extinct from their original sites or are diminishing. Therefore , it is absolutely necessary and essential to strategically safeguard and conserve biodiversity of the rice genepool and to effectively utilize the elite rice germplasm resources in rice breeding programs. This is the only way to guarantee the long2term and sustainable production of rice varieties.