DIFFERENCES IN THE CALLS OF EUROPEAN AND NORTH AMERICAN BLACK-BILLED MAGPIES AND THE YELLOW-BILLED MAGPIE

ABSTRACT

We compared several features of the chatter call of two races of black-billed magpies, the nominate, European race Pica pica pica and the North American race P.p. hudsonia and the yellow-billed magpie P. nuttalli. The chatter calls of the two North American species were much more similar to each other than either was to the European magpie. This information together with the recently determined similarities in the behaviour and social organisation of the two North American species, suggests that the phylogenetic affinities of these two species are closer than is implied by their taxonomic status.     

COMPARATIVE POPULATION STRUCTURE AND GENE FLOW OF A BROOD PARASITE,THE GREAT SPOTTED CUCKOO (CLAMATOR GLANDARIUS), AND ITS PRIMARY HOST,THE MAGPIE (PICA PICA)

The amount of gene flow is an important determinant of population structure and therefore of central importance for understanding coevolutionary processes. We used microsatellite markers to estimate population structure and gene flow rates of the great spotted cuckoo (Clamator glandarius) and its main host in Europe, the magpie (Pica pica), in a number of populations (seven and 15, respectively) across their distribution range in Europe. The genetic analysis shows that there exists a pattern of isolation by distance in both species, although the cuckoo data are only indicative due to a small sample size. Gene flow seems to be extensive between nearby populations, higher for magpies than cuckoos, and especially high for magpie populations within the area of distribution of the great spotted cuckoo. There is no correlation between genetic distances between magpie populations and genetic distances between cuckoo populations. We discuss the implications of extensive gene flow between magpie populations in sympatry with cuckoos for the population dynamics of hosts, in particular for the occurrence of egg rejection behavior in host populations and how the different rates of migration for both species can affect the dynamics of coevolutionary processes.     

青海省果洛大武地区高原鼠兔生态学初步研究

高原鼠兔(Ochotona curzoniae)是青藏高原上小型兽类的优势种。对高原鼠兔生态学的研究,以往已有许多报道(张洁、王宗祎,1963;张荣祖、王宗祎,1964;皮南林,1965;施银柱等,1978;梁杰荣等,1978;肖运峰等,1979;王祖望等,1979),但关于青海南部高原(以下简称青南高原)本种的报道很少。1964-1965年,我们在青南高原的果洛大武地区,进行了高原鼠兔生态学调查,1980年又作了补充调查,现将所得资料整理出来,以供参考。     

EVIDENCE OF A ROLE OF HETEROCYSTS IN THE SPORULATION OF A BLUE-GREEN ALGA

Sporulation of vegetative cells adjacent to heterocysts is prevented by detachment of the two cell types, probably without impairment of the capacity of those vegetative cells to sporulate. Apparently, therefore, heterocysts are in part responsible for the sporulation of vegetative cells attached to them.     

猕猴桃嫁接试验

本文报道猕猴桃不同嫁接时期、嫁接方法和不同分类群的砧木试验结果,猕猴桃最适宜的嫁接时期是落叶后至翌年萌芽前,嫁接方法以切接为好,嫁接成活率均在90％以上。同种和同一分类群的砧穗间有良好的亲和力,嫁接均有较高的成活率。不同分类群间嫁接效果较差,如中华猕猴桃桂海4号嫁接于中华猕猴桃砧木上的成活率,生长情况均比嫁接其它分类群为砧的有显著差异。     

云南森林植物区系研究

云南森林植物(系指木本植物)主要起源于新生代,少数古老种起源于古生代至中生代。云南森林植物区系成分极为丰富而复杂,据研究已知森林植物149科(蕨类植物1科,裸子植物10科,被子植物138科),840属,5271种。本文根据对云南森林植物15个分布区类型统计分析,证明云南森林植物区系明显富于热带性同时兼有丰富的温带成分,热带属占总属数72.12％,温带属占总属数21.87％,中国特有属在云南有46属,占云南总属数5.33％。中国特有属的三个分布中心。有两个分布中心在云南(即新特有属中心和古老特有属中心)。本文还对云南森林植物区系的地理成分起源;云南森林植物区系成分复杂、丰富之成因;云南森林植物开发利用之前景进行了研究和探讨。     

灵香草的一种严重病害调查研究初报

<正> 灵香草的斑枯病俗称“点蜡烛”病,历来是灵香草的毁灭性病害。此病分布于广西金秀县各个灵香草产区;融水、龙胜等灵香草产地亦有此病发生。一般发病率60～70％,严重的往往达80％～90％,甚至失收。如1980年8月,金秀县外贸局为扶植生产队发展灵香草生产,无偿拨给金秀二队种苗300斤,分给社员种植。灵香草生长到高约23—27厘米时,全部病死腐烂。因此,要发展灵香草生产,必须有效地防治这种病害。     

A CYTOGENETIC STUDY OF A THREE-PAIRED RACE OF HAPLOPAPPUS GRACILIS

Haplopappus gracilis (Nutt.) Gray is an aneuploid species of Compositae of wide distribution in the southwestern U.S.A. and northern Mexico. Except for 2 types of supernumeraries, cytological samples from throughout its range have regularly shown 2 pairs of chromosomes. However, recent collections from a small area in south-central Arizona had 2n = 4, 2n = 5, and 2n = 6 in the same population. The 2n = 5 plants were hybrids between the 2n = 4 and 2n = 6 types. Both natural and artificial F₁ hybrids show preferential disjunction from a trivalent and produce genetically balanced gametes with n = 2 and n = 3. In backcrosses of the F₁ to n = 2 plants, a 1:1 ratio of 2n = 4 and 2n = 5 plants was obtained. The possible mechanisms for the evolution of n = 2 from n = 3 and vice versa are discussed.