黄花烟草和枸杞属间原生质体融合再生杂种小苗

利用改良的PEG方法以2%的频率诱导黄花烟草原生质体和经IOA失活的枸杞原生体融合。在获得的250块愈伤组织中,有5块为形态上与枸杞愈伤组织类似。对这5块愈伤组织的过氧化物酶和酯酶同工酶分析结果表明,其中的2块(记作Hy2和Hy5)为对称程度较高的体细胞核杂种,其它3块为不对称核杂种或细胞质杂种。细胞学观察指出,Hy2和Hy5的平均染色体数目分别为98.2和59.3。此外,两个杂种的几乎所有中期细胞均含有结构变异的染色体。以小麦rDNA为探针的Southern杂交结果表明,Hy2和Hy5均含有双亲DNA特异片段。从Hy5再生出了形态上介于双亲之间的小苗。对再生苗叶片的酯酶同工酶分析指出,这些小苗含有双亲的特征酶带。     

悬钩子属和蔷薇属的新植物

本文发表了山莓两个新变型和小果蔷薇一新变型,即粉红山莓Rubus corchorifolius L.f.f.roseolus Z.X.Yu、重瓣山莓R.cor-chorifolius L.f.f.Hemi semiplenus Z.X.Yu,还有重瓣小果蔷薇Rosa cymosa Tratt.f.plena Z.X.Yu et G.Z.Liu。     

THE WEB-SPINNING PROCESS AND WEB-STRUCTURE OF LATRODECTUS TREDECIMGUTTATUS, L. PALLIDUS AND L. REVIVENSIS

The web structure and the web spinning process of Latrodectus tredecimguttatus Rossi, Latrodectus pallidus Cambridge and Latrodectus revivensis Shulov have been investigated, particular attention being given to the structure of their catching webs.
The webs of Latrodectus represent a further development of the web-type of Archaeranea tepidariorum . The specific characters of the investigated webs concern the middle layer of their three-layer webs, where more or less regular structures appear.
In the middle layer of L. tredecimguttatus web paths of hexagonal meshes appear.
In the web of L. pallidus and L. revivensis more or less regular radially arranged catching platforms appear, connected with the distant retreat by a long bridge-web.
The lower layer of vertical threads, with viscid droplets on their far ends is spread-out in L. tredecimguttatus and consists of short threads as distinct from the concentrated bundle of high threads in the two other species.
Since L. pallidus and L. revivensis appear usually among vegetation, their restricted catching webs seem to be adaptive adjustment to the biotope.
The concentration of the catching webs brings about improvement as regards prey detection.
The differences in the web structure of L. tredecimguttatus and L. revivensis indicate that their behavioural characters are more distinct than the morphological ones. The different behavioural characters support the view that L. revivensis represents a species different from L. mactans tredecimguttatus .     

西南地区绣线菊属和花楸属新植物

本文发表了我国四川和云南地区蕴薇科绣线菊属和花楸属的2新种和1新变种,即稻城绣线菊Spiraea daochengensis Lu,兰坪花楸Sorbus lanpingensis Lu和毛萼铺地花楸Sorbus reducta Diels var.pubescens Lu。     

BREEDING SYSTEMS IN ASCLEPIAS INCARNATA L., A. SYRIACA L., AND A. VERTICILLATA L.

A series of experimental pollinations involving three sympatric species provided strong evidence for physiological and/or genetic barriers to hybridization in Asclepias. Pollen tubes were observed to penetrate the style in some interspecific crosses of all species pairs. Aniline blue fluorescence microscopy also demonstrated pollen tube penetration of foreign ovules following pollinations between A. incarnata and A. verticillata. However, none of the 279 total pollinations attempted between species yielded mature seed, indicating the presence of late pre-fertilization or early post-fertilization incompatibility. Intraspecific pollinations in greenhouse and field populations revealed greater crossability between populations than within populations of a single species. Self-pollinations of A. verticillata were unsuccessful, while 29% and 4% of those of A. incarnata and A. syriaca, respectively, yielded mature follicles. It is suggested that the potential for autogamy, combined with floral mechanisms requiring pollination by insects, insure the advantages of both the genetic variability promoted by outcrossing and the reproductive assurance of uniparental reproduction. Strong reproductive barriers between species reduce the change of intergradation where species occur sympatrically.     

川芎,抚芎与藁本的花粉形态及其亲缘关系

本文讨论了我国传统中药伞形科藁本届Ligusticum L.植物藁本L. sinense、川芎L. sinense cv. Chuanxiong、抚芎L. sinense cv. Fuxiong的花粉形态及其相关性状,我们认为:川芎和抚芎与藁本相比,花粉形状变异很大,展示出明显的差异,但却仍然保留了藁本属矩形花粉类型的特征。其相关性状亦有不少相似性。因此,赞同将川芎、抚芎作为藁本的栽培变种。