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21.
三种观赏植物水培营养液配方初步研究 总被引:1,自引:0,他引:1
采用不同配方的营养液对彩叶凤梨、小叶榕和天竺葵进行了水培试验.结果表明:3 种植物对不同配方营养液有不同的适应性,大量元素为11.5 mg/L(以下单位同)NH4 -N 140.2 NO3--N 93.0 P 312.0 P 80.0 Ca 18.3 Mg 45.0 S的营养液(pH 6.12,EC 为1.32 ms/cm)较适合彩叶凤梨和小叶榕的生长,而天竺葵在大量元素为21.0 NH4 -N 137.2NO3--N 44.5 P 265.2 K 92.0 Ca 36.0 Mg 48.0 S的营养液(pH5.60,EC 为 1.35 ms/cm)中生长最好. 相似文献
22.
Relationships between land use, fertility and Andisol behaviour: examples from volcanic islands 总被引:1,自引:0,他引:1
Abstract. Soils developed on volcanic parent materials have many intrinsic qualities favourable to cropping. However, fertility decreases dramatically when they are badly managed. A short review and case studies from Réunion and Guadeloupe highlight the special characteristics of these soils, and their response to management.
The interplay of cropping systems and physical characteristics of Andisols is first considered through the example of Pelargonium and food crop systems in Réunion. Progressive decrease in production and cropping potential shows in falling yields as well as in the overall decline of the system. The example of banana production in Guadeloupe highlights the increase in inputs needed to realise the land's potential and to maintain yields, in particular more tillage and pest treatment.
In both cases, these trends are connected to the co-evolution of soil characteristics and cropping systems. They lead to an increase of risks with less security and less scope in the choice of cropping systems. Technical solutions in the form of erosion-control measures, rotation and planting techniques have been developed and prove to be relevant and consistent in their benefit. 相似文献
The interplay of cropping systems and physical characteristics of Andisols is first considered through the example of Pelargonium and food crop systems in Réunion. Progressive decrease in production and cropping potential shows in falling yields as well as in the overall decline of the system. The example of banana production in Guadeloupe highlights the increase in inputs needed to realise the land's potential and to maintain yields, in particular more tillage and pest treatment.
In both cases, these trends are connected to the co-evolution of soil characteristics and cropping systems. They lead to an increase of risks with less security and less scope in the choice of cropping systems. Technical solutions in the form of erosion-control measures, rotation and planting techniques have been developed and prove to be relevant and consistent in their benefit. 相似文献
23.
Judith L. Fisher William A. Loneragan Kingsley Dixon Julie Delaney Erik J. Veneklaas 《Biological conservation》2009,142(10):2270-2281
Relationships between fire history, vegetation structure and composition, and invasion by introduced plant species have received limited attention in Australian woodlands. A study in a Mediterranean, fire adapted urban Banksia woodland remnant in the biodiversity hotspot of southwest Australia investigated: (1) Have significant changes occurred in the woodland tree canopy between 1963 and 2000? (2) Do correlations exist between fire frequency and canopy cover? (3) If there is a difference in the vegetation composition of Banksia woodland invaded by the South African Ehrharta calycina (PCe) and Pelargonium capitatum (PCp) compared to largely intact remnants (GC)? and (4) Do correlations exist between vegetation condition, composition, fire frequency and invasion? Aerial photography, processed in a Geographical Information System, was used to establish fire history and changes in canopy cover over time (1963–2000). PCe and PCp sites experienced the greatest number of fires, with a net reduction in canopy cover in all areas experiencing four or more fires (60% of all woodlands). Frequent fire corresponded with a decline in native cover, richness and diversity, a shift from native to introduced species, changes in the relative importance of fire response categories, and loss of native resprouting shrub cover. Life forms of introduced species, which included no trees, shrubs and perennial sedges, contrasted strongly with those of native species, which had poor representation of annual and perennial grasses. Clear ecological and conservation consequences due to the loss of species diversity, changes in fire ecology and invasion have occurred in the Banksia woodlands. This study provides an understanding of the invasion process, enhancing conservation knowledge to improve the adaptive management of the key threatening process of invasion in biodiverse communities. 相似文献
24.
驱蚊香草快繁体系的建立及工厂化育苗主要影响因素研究 总被引:2,自引:2,他引:0
以驱蚊香草的幼嫩叶片作外植体,在含不同激素的不同培养基上进行丛生芽的诱导、芽的继代增殖、芽生根与移栽研究,以快速获得再生植株。结果表明,丛生芽诱导培养基以MS+6-BA1.0mg/L+NAA0.1mg/L较好,诱导率为96%;增殖培养基以MS(B5)+6-BA0.5mg/L +NAA0.1mg/L较好,增殖系数达8倍以上,且增殖芽生长好;壮苗培养基为MS(B5)+6-BA0.1mg/L+NAA0.2mg/L为好;生根培养基以1/2MS+NAA0.1 mg/L和MS+IBA0.2 mg/L为最佳,生根率达100%,幼苗生长势旺。影响工厂化育苗的主要因素有激素浓度、继代次数和移栽管理 相似文献
25.
26.
不同月份香叶天竺葵精油的含有率与成分变化分析 总被引:3,自引:0,他引:3
对生长在上海地区的香叶天竺葵(Pelargonium graveolensL.)不同月份的精油的含有率及其成分变化进行研究。采样后,用水蒸馏法提取精油,用GC-MS对精油成分进行分析;结果显示,在6月份和9月份精油含有率最高,精油含有率最低的是在1月份。无论哪个月份的精油,在它们的成分中,香茅醇及它的酯类的含量最高,其次是香叶醇和它的酯。 相似文献
27.
F. Pohlheim 《Plant Breeding》1986,97(1):93-96
In reciprocal crosses between Pelargonium zonale and Pelargonium inquinans uniformly green, uniformly bleached and variegated plants occurred among the F1 progeny. The effect has been described as hybrid variegation and also as hybrid bleaching. Because of the differences among the reciprocal crosses, it is assumed that the zonale-plastids undergo normal development in hybrids, while the plastids of Pelargonium inquinans do not develop normally due to their interaction with the nucleus of the hybrid. Using the results obtained in the experiments, the development of zonale-hybrids from Pelargonium is discussed. 相似文献
28.
W. Horn 《Plant Breeding》1994,113(1):3-17
Different Pelargonium hybrids are of great importance to horticulture. Breeding; for F1 hybrid and clonal eultivars is particularly prevalent in Europe, Japan and North America. The results of a great deal of breeding research are scattered throughout different journals and published in several different languages. The aim of this review is to summarize the results of research on interspecific crosses and the inheritance of flower and leaf colour, plant habit, resistance and floret type. 相似文献
29.
30.
为了研究‘地平线’天竺葵的花芽分化特性及光周期对其生长发育的影响,采用石蜡切片
方法观察了花芽分化的过程,探讨了7 种光周期处理对始花期及开花质量的影响。结果表明:(1)‘地平
线’的花芽分化过程可以划分为8 个时期,持续时间大约为9 周;(2)‘地平线’花芽分化时期与各生长
指标(株高、株幅、真叶数和播种周数)均极显著相关,通过回归方程判断其幼龄期在5 片真叶前结束;
(3)‘地平线’为量性短日照植物,促其早花的最佳光周期为昼12 h/夜12 h;(4)较长日照下‘地平线’
的株形高大松散,较短光周期下矮小紧凑。‘地平线’天竺葵在5 片真叶前,采用16 h 日照栽培,可得到
健壮幼苗;5 叶期后,12 h 日照诱导,可促进分枝开花。 相似文献