首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 875 毫秒
1.
红木字典     
《生命世界》2012,(7):8-11
紫檀木(类)檀香紫檀:中乔木;直径0.4~0.7米。商品名Red sanders,Red sandalwood,Saunderswood。主产于印度南部,印度半岛东南部东高止山脉南段安得拉邦区域,包括古德柏、奇图尔、内洛尔、科努尔、蒂鲁帕蒂、帕拉马南等地区。尼泊尔、缅甸、泰国、柬埔寨和中国华南等地引种栽培。  相似文献   

2.
红木字典     
《植物杂志》2012,(7):8-13
紫檀木(类)檀香紫檀:中乔木;直径0.4~0.7米。商品名Red sanders,Red sandalwood,Saunderswood。主产于印度南部,印度半岛东南部东高止山脉南段安得拉邦区域,包括古德柏、奇图尔、内洛尔、科努尔、蒂鲁帕蒂、帕拉马南等地区。尼泊尔、缅甸、泰国、柬埔寨和中国华南等地引种栽培。  相似文献   

3.
粤东沿海引种无瓣海桑试验   总被引:4,自引:0,他引:4  
黄陵  詹潮安 《生态科学》2003,22(1):45-49
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.  相似文献   

4.
 本文根据生态环境因子的分析,对油橄榄在原产地和汉中地区引种的气温、降雨量(特别是降雨季节分配)和日照及土壤条件的分析研究表明:旱季灌溉和雨季排水,改善土壤的物理性,调正pH值及施钙、磷、硼等来补充某些生态因子的不足,并需选择适应我国气候条件的品种,才是引种的重要途径。  相似文献   

5.
褐云玛瑙螺的生态研究   总被引:1,自引:0,他引:1  
褐云玛瑙螺(Achatina fulica Férussac)在闽粤一些地区俗称花螺、菜螺、东风螺、非洲蜗牛等。原产地为东非大陆,上世纪中期,传入印度,以后逐渐扩及东南亚与南洋群岛,第二次世界大战期间传入美洲。  相似文献   

6.
将原产于黑龙江省小兴安岭凉水自然保护区的野生柳兰栽培至具大陆性季风气候特点的哈尔滨市内。引种观察结果表明,通过与原产地同年生野生柳兰生长特性的比较,引种地柳兰植株生长发育正常,在人工栽培条件下能够安全越冬和越夏。根据柳兰植株生长量增长时期的特点划分了柳兰在引种地生长的4个时期;与原产地比较,柳兰花序数量、单花序中小花数量、花朵大小、花柄长度、花萼长度等数量性状均有增加,观赏特性优良。但引种地花序长度和蒴果长度小于原产地,且原产地的花朵大小比引种地的更均匀。本试验获得了野生柳兰在同纬度相同气候类型区域的引种栽培的基础数据,为柳兰在城市园林绿化中栽培应用奠定了基础。  相似文献   

7.
毕伯钧 《生态学报》1984,4(4):364-371
本文根据西洋参生育的生态环境及原产地的气候条件,探讨了辽东地区引种栽培西洋参的可能性,利用气候生态因子,采用模糊相似优选比方法,确定了辽东地区引种扩种西洋参的适宜气候生态区域。  相似文献   

8.
本文根据西洋参生育的生态环境及原产地的气候条件,探讨了辽东地区引种栽培西洋参的可能性,利用气候生态因子,采用模糊相似优选比方法,确定了辽东地区引种扩种西洋参的适宜气候生态区域。  相似文献   

9.
通过原产地调查,引种试验,扦插及种子萌发等实验,研究了太行花的繁殖及扩散方式。结果表明,太行花有两条生殖途径:一条是有性生殖;另一条是无性生殖。在原产地因生境条件特殊,有性生殖能力弱,主要靠无性生殖扩大种群。在北京人工栽培条件下,两种生殖方式都能正常进行。  相似文献   

10.
厦门地区甜菊栽培技术总结   总被引:1,自引:0,他引:1  
甜菊[Stevia rebaudiana (Bertoni) Bertoni]原产于南美巴西、巴拉圭、阿根廷三国交界阿曼拜山脉,是亚热带多年生菊科草本植物,在原产地大部分处于野生状态,尚未大规模栽培。近几年来,甜菊化学成份和药理研究有了较大进展;日本、南朝鲜、巴西、我国台湾省等国家和地区的重视和栽培,扩大了引种和生产种植,但生产上仍然是小规模种植。我所在1978年4月从日本引种试种获得成功的基础上,1979年又扩大栽培试验,初步摸索一些栽培技术经验,提供参考。  相似文献   

11.
We investigated the effect of intraspecific competition on the magnitude of inbreeding depression in Impatiens capensis by planting seeds from chasmogamous (CH) and cleistogamous (CL) flowers in three experimental greenhouse treatments: in individual pots, in flats in dense pure stands according to seed type, and in flats with the two seed types intermixed in a checkerboard array. The size distributions of plants grown in flats were significantly more hierarchical than those of plants grown individually, indicating that larger plants competitively suppressed smaller plants in the high-density treatments. The magnitude of inbreeding depression at high density depended upon the planting arrangement of CL and CH seeds. CH advantage was greatest when CH and CL seedlings were grown in competition with one another, suggesting that fitness differences between outcrossed and inbred individuals were intensified by dominance and suppression. For plants grown individually, the effects of maternal parent, seed weight, and emergence date on seedling size disappeared with plant age, whereas at high density these effects remained at the final harvest. Thus, plant density may influence patterns of natural selection both on mating system and on juvenile traits in natural Impatiens populations.  相似文献   

12.
豌豆花DNA直接导入小麦体可诱导小麦种子蛋白质组分发生明显的变化,小麦种子蛋白质和总氨基酸含量都比对照增高20%。这些变异性状能稳定遗传给后代。因此直接导入豌豆花DNA技术可以为小麦品质改良和分子育种研究提供一条新途径。  相似文献   

13.
《新西兰生态学杂志》2011,31(2):143-153
Native plants are an important part of New Zealand?s uniqueness, and there is increasing awareness of the need to maintain these species in managed landscapes, particularly pastoral areas, in addition to the country?s conservation lands. The most widely used method of establishing native plants is transplanting nursery-grown seedlings, and for many species, much experience and knowledge has been gained in using this technique. Establishment of native plants in the field by direct seeding is a potentially useful alternative technique-which has been evaluated in the North and South Islands only to a limited extent. This paper reviews the current state of knowledge on the direct seeding of species into pastoral areas. It covers site and species selection, seed availability and quality, site preparation, and post-sowing management. It also compares the economics of native plant establishment by transplanting and by direct seeding. Direct seeding of pastoral areas is a relatively cheap technique, but its general applicability is currently limited because of frequently inadequate supplies of viable seed, lack of knowledge on appropriate sowing times and rates, unreliable field germination and seedling emergence, and frequent intense competition from existing vegetation, particularly exotic grasses.  相似文献   

14.
An important component of the process of coevolution between plants and their insect herbivores is the imposition of selection on plants by insects. Although such selection has been inferred from indirect evidence, little direct evidence for it exists. One goal of this study was to seek direct evidence by determining, for a single plant-herbivore system, whether insect herbivores impose selection on their host plants. A second goal was to determine whether costs are associated with genotypes that confer resistance to herbivores, as has been commonly postulated. The annual morning glory, Ipomoea purpurea, exhibits genetic variation in resistance to four different types of insects. For three of these types, most of the genetic variation is additive. Removal of insect herbivores increased the number of seeds produced by I. purpurea by 20% and eliminated additive genetic variation for seed number (fitness). This result implies that herbivores impose selection on some trait(s) of their host plants. Coupled with selection for decreased damage by corn earworms, as revealed by a negative additive genetic covariance between damage and fitness, this result suggests that insect herbivores impose selection on resistance to corn earworms in I. purpurea. Two types of cost of resistance to herbivores were sought in I. purpurea: 1) internal trade-offs in allocation of resources and 2) ecological trade-offs between resistances to different insects. No costs of either type were detected. This result suggests that cost-benefit arguments that attempt to predict the evolution of levels of resistance to herbivores are not applicable to I. purpurea.  相似文献   

15.
The methods employed in a restoration can impact the resulting plant community. This study investigated the effect of restoration method on several indices of plant community structure by comparing two restoration methods conducted over an 8‐year period to a naturally colonized postagricultural field and a remnant grassland. The restoration methods included (1) distributing seed over fallow fields and (2) planting established seedlings in combination with seeding a fallow field. We found greater plant community resemblance (i.e., floristic quality, native species richness, and native diversity) to remnant grasslands with the introduction of seedlings during the first 4 years of restoration. There was also a negative correlation between the native plant diversity and the density of exotic plants in the restoration. This relationship suggests that introducing native plants in postagricultural fields may represent an effective management strategy to reduce exotic plant density.  相似文献   

16.
To revegetate native plant communities, it is often cheaper to direct seed than to plant nursery‐grown stock. However, the outcomes of direct seeding can be quite variable, and it is unclear whether direct seeding or planting is more likely to facilitate the restoration of diverse plant communities. To address this question, we compared the outcomes of each method across several recent riparian revegetation projects where both direct seeding and tube‐stock planting were used. We surveyed riparian revegetation projects at seven sites within the greater Melbourne area that had been revegetated between 1 and 4 years previously. Sites were all on land previously used for agriculture or degraded public land and ranged in environmental and climatic conditions. Woody plant density, establishment of target species, species richness, species diversity (evenness) and plant heights were assessed. Direct seeding tended to result in higher plant densities and similar species richness, but lower rates of species establishment and diversity compared with planting. A median of 67% of target species established via direct seeding compared with 100% for planting, with direct seeded areas often dominated by one or two species. In general, overall revegetation outcomes were often driven by climatic and site factors, rather than revegetation method. We suggest that to achieve good restoration outcomes from revegetation in riparian areas, a bet‐hedging or combined approach using both sowing and planting may be the best strategy.  相似文献   

17.
本试验初步研究了华南双季早稻秧苗于不同育秧方式和施肥水平下的生长特点,结果表明:(1)旱育秧与湿润育秧秧苗在形态生长上的差异主要在于秧苗的叶片数不同,湿润育秧的出叶速度比旱育秧明显地快.(2)在有机质含量较高通气性能较优良的砂质壤土上进行旱育秧,基肥种类与施肥量在一定范围内时,具5片叶以下的旱育小苗的叶片数和株高无显著差异。(3)播后5天内的出苗率湿润育秧比旱育秧要显著地快而齐,而成秧率则各处理间有高有低,无明显规律可循,这与我们过去报道的结果趋势一致。(4)旱育秧移栽后的发根力比湿润秧要强,这种优势可维持到第9天才消失,再加上白/褐根的比例湿润秧要大,可能是导致旱育秧移栽后根系“爆发力”强、返青活棵快的重要因素。  相似文献   

18.
To determine the effects of density, genotype, and their interaction on individual seed mass in Raphanus sativus L., we replicated maternal and paternal families of seed across two planting densities in an experimental garden. Seeds were produced by a nested breeding design performed in the greenhouse. Among garden-raised plants, density had a strong negative effect on the mass of seeds produced. At low density, the identity of the greenhouse-grown maternal plants had a strong effect on F2 seed mass, while in high-density plots, there were no significant parental effects on mean seed mass. Significant parental genotype density interactions contributed to variation in F2 seed mass. Norms of reaction for each of the 15 paternal sibships illustrate paternal family density interactions. Three sibships exhibited significant declines in mean seed mass with increasing density; 12 sibships showed no change. Maternal family density interaction effects on seed mass were also detected; among maternal sibships, mean seed mass at low density was negatively correlated with mean seed mass at high density. These results demonstrate: a) planting density has a strong effect on mean individual seed mass produced by adults; b) density influences the magnitude of maternal effects on progeny phenotype; and c) genotype density interactions influence seed mass, potentially contributing to the maintenance of maternal genetic variation in seed mass in natural populations of wild radish.  相似文献   

19.
矮沙冬青种子特性和萌发影响因素的研究   总被引:28,自引:0,他引:28       下载免费PDF全文
 对矮沙冬青(Ammopiptanthus nanus)种子的特性和萌发影响因素进行了初步研究,结果表明:种子不易传播;虫蛀率高,室温贮藏60 d的种子虫害率为38%;易形成硬实,含水量为7.68%的种子在30 ℃温水中浸泡90 h,只有33.33%能吸水膨胀。种子萌发时不需光,在15~30 ℃和室温(18~32 ℃)条件下,经9 d的萌发,发芽率均可达80%以上,30℃时萌发最快;在1~2 cm深的沙壤中,种子出苗率可达75%以上,超过3 cm显著降低,超过6 cm则低于20%;种子在沙壤中萌发时,沙壤的适宜湿度为19.35%~28.75%,高于32.43%或低于3.85%,很少有种子萌发;含水量分别为19.36%、10.64% 和7.68%的种子发芽率无显著差异,在-10 ℃和5 ℃下贮藏7个月,发芽率也无显著降低,但在室温和35 ℃下贮藏7个月则显著下降,发芽率下降的速度与种子本身的含水量和贮藏温度正相关;在湿度分别为7.41%、13.79%和28.57%的沙壤中播种育苗,幼苗死亡率高达77.49%、81.25%和89.49%,即使用三唑酮拌种,死亡率亦高达50.27%、69.53%和76.03%,幼苗死亡率与沙壤湿度正相关。  相似文献   

20.
Surface mining has caused significant disturbance globally, and is responsible for the loss of more than 600,000 ha of the world's largest temperate deciduous forest in the Appalachian region of the United States alone. Due to the heavy disturbance on mine lands, invasive plants have become dominant on many former coalfields, some of which were intentionally planted with exotic species. The establishment of invasive plants on these disturbed lands has often led to reductions in establishment of desirable native species. Autumn olive (Elaeagnus umbellata), an exotic nitrogen‐fixing shrub, is a problematic invasive species on reclaimed sites in Appalachia. To better understand how reclamation conditions affect autumn olive, we assessed the effects of the mine‐soil substrate and vegetation seeding on autumn olive establishment and growth. In each experiment, we also manipulated the herbaceous plant community to further examine effects on autumn olive establishment and growth. In spring 2015, we transplanted 480 1‐year‐old autumn olive seedlings across both experiments. After 2 years of growth, autumn olive performed better in weathered‐rock than in unweathered‐rock substrates; in bare‐ground plots than in vegetated plots; and in tree‐compatible (low‐competition) seeding than in more‐competitive conventional seeding. No treatment precluded autumn olive establishment. However, our results show that strategic use of beginning substrates and planting mixes can have strong inhibitory effects on invasive plants, but also that substrate and herbaceous‐plant community conditions favorable to establishment of native trees are also favorable to autumn olive.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号