郁金香在国外具有400多年的栽培历史,选育出的郁金香品种有8000多个.我国从20世纪80年代开始从国外引进郁金香种球进行栽培,目前郁金香已经成为农民增收和城市、公园绿化的重要球根花卉.但我国使用的郁金香种球,完全依靠从国外进口,这不仅增加了生产成本,更是我国郁金香产业可持续发展的最重要制约因素.本文主要介绍北方地区郁金香露地种球扩繁技术,以为我国郁金香种球繁育者提供参考.

The genetic diversity of Disanthus cercidifolius var. longipes from five wild populations in Nanling was studied by means of ISSR markers,in order to provide theoretical basis for the protection and sustainable utilization of the endangered plant. Eight ISSR primers gave rise to 101 discernible bands,of which 64( 63. 37%)were polymorphic. The total Nei's genetic diversity index was 0. 285 9,genetic diversity within populations( Hs) was 0. 274 1,indicating a relatively lower genetic variation at the species level. At the population level,the percentage of polymorphic bands were 60% ~ 75%,Nei's genetic diversity index were 0. 269 5 ~ 0. 282 4,Shannon's information index were 0. 384 5 ~ 0. 399 9. Daoxian population and Mangshan population had higher genetic diversity levels. Genetic differentiation among populations was 0. 041 4,indicating a large proportion of genetic diversity( 95. 86%) was resided among individuals within populations. The UPGMA cluster analysis showed that the five populations were not basically clustered according to their geographic distances,it was surprising that the two Lianzhou populations( LZX and LXD) clustered firstly with Jinggangshan population( JGS),the reason should be explored further.

Based on the analysis of the cluster and areal types of family and genera of seed plants by Wu Zheng-yi, the floristic diversity of 6 communities with Disanthus cercidifolius var.longipes in different areas (Sanqing Mountain,Jinggangshan Mountain,Junfeng Moutain and Guanshan Mountain in Jiangxi Province;Li-anhuashan Mountain in Kaihua County,Zhejiang Province) were studied.The results showed that the floristic composition of the communities is complex, there are 283 species belonging to 170 genera and 50 families based on preliminary identification and statistics of all the communities.The distribution type analysis of fami-lies,genera and species indicated that the geographical elements are diverse.There are similarities and differ-ences in the floristic characteristics of the 6 communities,there is extensive relationship among the florae.Ac-cording to the floristic elements of families and genera,the tropical distribution is of the same ratio as the tem-perate one,indicating the transitional floristic characteristics from the tropic zone to the temperate zone.The flo-ristic element clustering analysis showed that the florae of the 6 communities are closely related.

The teachers curriculum quality refers to the professional quality that teachers ought to possess in understanding and developing the curriculum. From the perspective of individual quality structure, the teachers curriculum quality is composed of three elements including curriculum knowledge, curriculum ability and curriculum aptitudes. Effective teachers training and active participation as well as action research are the main channels of training, developing and optimizing the structure of teachers curriculum quality and raising the teachers capacity of participation in the curriculum development.

Biological invasion has become one of the hot spots of ecologic environment problems in the world. The study on the ecologic risk evaluation of invasive alien plants is aim to evaluate qualitatively and quantitatively the probability of the alient plants invasion and the damage that it could bring to the ecosystem, and to reach the goal of ecological risk management so as to improve the eco-environment and economic coordinated development. Basded on the present situation of invasive alien plants ecological risk evaluation in China, this thesis mainly comprehensively analyzed the sources of invasive alien plants ecological risk and the damage which may cause, explored the assessment method and comprehensive evaluation model on the invasive alien plants ecological risk, established the indexes system and judging standard of alien plants invasive risk, and classified the alien plants risk levels in our country. In the end of thesis, some suggestions on the ecological risk management of invasive alien plants were put forward.