引种桉树对本地生物多样性的影响

桉树以速生和适应多种环境的特性成为世界著名的造林树种.但引种桉树对环境可能产生负面影响,如导致土地退化、地下水水位下降和多样性降低等,特别是对林下本地生物物种多样性的影响及其原因还存有争议.本文对此进行了综述,认为大部分桉树人工林本地物种数量低于天然林,一般不高于乡土树种人工林,但总体上好于其他外来树种人工林.导致桉树人工林生物多样性低的原因主要是桉树的生理生态特性、人类不合理的规划和砍伐等,其中人为因素起主导作用.若根据引种地的群落性质,通过严格的设计和科学管理,可以将这种负面影响最小化.应按照有利于群落正常发育和植被更新的方式栽种桉树人工林,保留天然植被,减少人为干扰,从而减轻引种桉树的负面影响.     

四川攀西地区南亚热带观赏花卉引试种初报

本文报道四川攀西地区引进的53科143个观赏花卉品种的引种试种情况。结果表明,所引进的品种在攀西地区均表现为适应性较强,可望成为今后该地区发展观赏花卉的主导品种。     

六个早熟鲜食欧亚葡萄品种引种初报

本文以早玉、京秀、京玉、黄提、奥古斯特、维多利亚六个早熟鲜食欧亚葡萄品种为试材,在避雨设施条件下,对其主要物候期、果实经济性状、品种抗病性、二次果发育及产量情况进行观察。结果表明,六个品种间在产量、品质、抗病性等方面有明显差异。按综合性状比较,表现最好的是京秀,其次是奥古斯特,这两个品种在宁德市有避雨设施的葡萄栽种区具有一定推广价值。     

Population heterogeneity of plasmid-bearing and plasmid-freeBacillus subtilis strains under different environmental conditions

The population heterogeneity of recombinant and plasmid-freeBacillus subtilis strains introduced into aquatic microcosms was studied. After introduction, the population of the plasmid-free strainB. subtilis 2335 in microcosms has long been represented by both vegetative cells and spores, whereas, already ten days after introduction, the population of the recombinant strainB. subtilis 2335/105 (Km^rInf⁺) was represented only by spores. The number of plasmid copies in the spore isolates of the recombinant strain was the same as before introduction, but the plasmid abundance in the vegetative isolates of this strain decreased. The isolates ofB. subtilis 2335/105 obtained from microcosms and the variants of this strain obtained by ten successive subcultures on M9 and 0. I× M9 media with and without kanamycin (Km) differed in the number of plasmid copies, Km resistance, and maximum biomass yield during batch cultivation. Irrespective of the presence of Km, more than 50% of the variants subcultured on M9 medium showed reduced plasmid abundance. At the same time, about 70% of the variants subcultured on 0.1 × M9 medium with Km and 90% of the variants subcultured on the same medium without Km retained the initial number of plasmid copies. The variants subcultured on media with Km retained the initial biomass level. In more than 70% of the variants isolated from media without Km, the biomass yield increased.     

厦门地区百合新品种引种栽培

本文总结了厦门园林植物园25个百合新品种的引种栽培表现,探讨栽培管理中光照、温度、土壤pH、施肥、病虫害等若干因素的影响。     

浙江植物引种驯化研究进展与思考

引种驯化是增加植物资源的一种传统育种方法。本文从浙江省农业科学院亚热带作物研究所引种驯化研究发展回顾入手,剖析了温州植物引种结果,以方法的改进反映浙江现代引种驯化学术水平的进步,最后讨论了植物引种驯化研究的若干问题。     

Naturalization and invasion of alien plants: concepts and definitions

Abstract.  Much confusion exists in the English-language literature on plant invasions concerning the terms 'naturalized' and 'invasive' and their associated concepts. Several authors have used these terms in proposing schemes for conceptualizing the sequence of events from introduction to invasion, but often imprecisely, erroneously or in contradictory ways. This greatly complicates the formulation of robust generalizations in invasion ecology.
Based on an extensive and critical survey of the literature we defined a minimum set of key terms related to a graphic scheme which conceptualizes the naturalization/invasion process. Introduction means that the plant (or its propagule) has been transported by humans across a major geographical barrier. Naturalization starts when abiotic and biotic barriers to survival are surmounted and when various barriers to regular reproduction are overcome. Invasion further requires that introduced plants produce reproductive offspring in areas distant from sites of introduction (approximate scales: > 100 m over < 50 years for taxa spreading by seeds and other propagules; > 6 m/3 years for taxa spreading by roots, rhizomes, stolons or creeping stems). Taxa that can cope with the abiotic environment and biota in the general area may invade disturbed, seminatural communities. Invasion of successionally mature, undisturbed communities usually requires that the alien taxon overcomes a different category of barriers.
We propose that the term 'invasive' should be used without any inference to environmental or economic impact. Terms like 'pests' and 'weeds' are suitable labels for the 50–80% of invaders that have harmful effects. About 10% of invasive plants that change the character, condition, form, or nature of ecosystems over substantial areas may be termed 'transformers'.     

苦丁茶在海南儋州的引种试种

在海南儋州进行苦丁茶引种试验。结果表明,儋州地区适宜种植苦丁茶,且能获得较高产量。田间试验表明,适当遮阳能促进植株的生长,灌溉是种植成功并获得高产的重要条件;生产中要加强技术管理,培养合理的树冠,以便保持持续的高产、稳产。     

粤东沿海引种无瓣海桑试验

粤东沿海引种无瓣海桑试验4年的结果表明:该引种区分别比原产地及我国已引种成功的湛江、深圳更北1°08'2°22'和1°06',有其特殊的生长发育、生态适应性等特点以及造林、管护等技术规程,共造林面积243.3hm²,是目前我国该树种引种最北、面积最大、引种最成功的林分.经观测,该林分生长发育正常,在适宜生境下,造林后1年平均树高生长可达2.24m,比乡土树种提前6～7年实现防护作用:造林后一年开花结实,每年2次,能自然更新,1998年9月种植的林分已出现4期自然更新小苗,而且,其抗逆性、经济品质等生物、经济学特性与原产地基本相同.