Interspecific hybridization between three closely related ornamental Eucalyptus species: E. macrocarpa,E. youngiana and E. pyriformis

Summary

Interspecific hybridization between thre Eucalyptus species with horticultural merit, E. macrocarpa, E. pyriformis and E. youngiana, was undertaken to investigate the likelihood of success of such crosses. All combinations produced fertile seed, with interspecific crosses as successful as intraspecific. There were no differences between male species in fertility but there were differences between female trees within a species. Discriminant analysis of each cross indicated a high degree of interspecific hybridization for hybrid 166 seedlings, with all except two seedlings clustering separately from a mixture of selfed and outcrossed seedlings of either parent, when measured for a range of leaf and stem characters at three different nodes. The success of this programme in producing both large numbers of seed and large numbers of hybrids indicated that it is possible that these species could hybridize naturally if they were growing in the same location. It also demonstrated the potential of controlled pollination, between closely related species of similar floral morphology, and seedling-based hybrid recognition as a method to produce eucalypt hybrids for further evaluation for commercial horticulture.     

人工栽培条件下3种野生葱属植物形态及年生活史特征

掌握国内仅分布于新疆的3种野生葱属植物人工栽培过程中形态及年生活史特征,为人工栽培条件下的环境控制提供依据。以新疆野生分布的新疆蒜、健蒜和多籽蒜为研究对象,在人工栽培条件下,于开花期观察形态指标;基于物候观察方法,在田间详细记录其年生长发育动态。结果表明,供试材料均为多年生草本植物,鳞茎单生,伞形花序,无珠芽。花梗基部无小苞片,花完全开放时,花被片成辐射状,具6枚花被片、6枚雄蕊和1枚雌蕊,子房扁球状,绿色,具疣突,子房3心室,除新疆蒜无蜜穴外,其余均具蜜穴。其中,新疆蒜具25~92枚小花,小花白色,每心室具4~8枚胚珠,年生活史85 d,其中从开始抽薹到种子散落约52 d。健蒜具20~66枚小花,小花深紫红色,子房腹缝线处有具帘蜜穴,每心室具4~6枚胚珠,年生活史96 d,其中从开始抽薹到种子散落约66 d。多籽蒜具18~64枚小花,小花粉红至紫红色,每心室具4~6枚胚珠,年生活史97 d,其中从开始抽薹到种子散落约56 d。新疆气候条件下的3种葱属植物具有早春萌动特征,具有一定的抗寒、抗旱能力,人工栽培条件下完成生殖生长,夏季高温来临前完成年生活史。可以作为早春露地栽培蔬菜和观赏花卉进行驯化栽培。     

An evaluation of pre-emergent herbicides for container-grown ornamental plants

Two applications of 5 herbicides were evaluated during spring and summer for weed control and phytotoxicity on 25 species of trees, shrubs and herbaceous perennials. Weed control was considered to be effective if herbicide-treated pots contained at most 20% of the weeds in untreated pots. Oxyfluorfen applied at 1.25, 2.5 and 5.0 kg ha^?1 provided effective control of grass and broad-leaved weeds for 8 weeks after the first application, and the 2 higher rates effectively controlled all weeds for 12 weeks after the second application. Oxadiazon at 2.0, 4.0 and 8.0 kg ha^?1 effectively controlled all weeds for 8 weeks after the first application, but only the highest rate was effective 12 weeks after the second application. Napropamide at 5.0, 10.0 and 20.0 kg ha^?1 effectively controlled grasses for up to 12 weeks, but only effectively controlled broad-leaved weeds at the 2 higher rates for 8 weeks after the first application and failed to control them after the second application. Alachlor at 4.0, 8.0 and 16.0 kg ha^?1 and oryzalin + trifluralin at 0.5, 1.0 and 2.0 kg ha^?1 provided effective control of grasses for 8 weeks after the first application. These herbicides at the highest rate also controlled broad-leaved weeds for 8 weeks after the first application. However alachlor and oryzalin + trifluralin failed to provide effective control of any weeds after the second application.Competition from weeds reduced the shoot dry weight (SDW) of unweeded control pots by 20% compared with hand-weeded control pots. None of the herbicides produced visible clamage in any plants. The SDW of 8 species treated with some of the herbicides was significantly lower than the corresponding hand-weeded control plants, and for 6 of these species some herbicide treatments were identified as being possibly phytotoxic. Oxyfluorfen appeared to inhibit the growth of Photinia and Coleonema, and alachlor inhibited the growth of Photinia, Eriostemon, Azalea ‘Splendens’, Lavendula and Coleonema. Oryzalin + trifluralin appeared to inhibit the growth of Bauhinia, and napropamide and oxadiazon inhibited the growth of Coleonema.     

Effect of growth inhibitors on three ornamental species

Foliar sprays of the growth inhibitors sodium 2, 3:4, 6-di-O-isopropylidine-α L-xylo-2-hexulofuranosonate (dikegulac-sodium), N-[2,4-dimethyl-5-] [tri-fluromethyl) sulfonyl] amino] phenyl] acetamide (mefluidide); methyl-2-chloro-9-hydroxyfluorene-9-carboxylate (chlorflurenol) and 2,3 dihydro-5-6-diphenyl-1,4-oxathiin (UBI-P293) were applied to Ligustrum japonicum, Pyracantha coccinea and Osmanthus heterophylla. Results indicate that growth inhibitors differ in their capacity to inhibit vegetative growth, and the level of inhibition and plant phytotoxicity depend on both the chemical and the rate of concentration.     

Interspecific hybridization in Lonicera caerulea and Lonicera gracilipes: The occurrence of green/albino plants by reciprocal crossing

Lonicera caerulea L. var. emphyllocalyx (Maxim.) Nakai is a berry crop cultivated in cold regions. So far, commercial cultivars have been mainly introduced from selection of wild plants. Therefore, fruit traits and other agricultural characteristics have been limited. In this study, interspecific crosses between L. caerulea var. emphyllocalyx and Lonicera gracilipes var. glabra Miquel were examined to increase genetic variability of L. caerulea var. emphyllocalyx. Seedlings were obtained from reciprocal crosses between L. caerulea var. emphyllocalyx and L. gracilipes var. glabra. The hybrid nature of seedlings was confirmed with random amplified polymorphic DNA analysis. Viable green plants were obtained efficiently from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx. In contrast, all plants produced from L. caerulea var. emphyllocalyx × L. gracilipes var. glabra were albino. These albino plants were very weak and only survived in culture condition. The chlorophyll deficiency was unilaterally observed, suggesting the occurrence of nuclear–cytoplasmic incompatibility. Viable F₁ hybrids obtained from L. gracilipes var. glabra × L. caerulea var. emphyllocalyx are amphidiploid (2n = 4x = 36) as showing same to both parents. The hybrid plants are expected to increase the variability of fruit traits, and may have heat tolerance from L. gracilipes var. glabra.     

不同观赏海棠品种的花粉及授粉特性研究

以14个观赏海棠品种为试材,进行了花粉萌发率和耐贮藏能力、热激处理诱导2n花粉和观赏海棠与国光苹果杂交亲和力测定等试验。结果表明,14个品种的花粉在-20℃条件下贮藏1~2个月后,除个别品种外,均能保持一定的萌发率,具有一定的耐贮藏能力;38℃/6小时热激处理可以提高观赏海棠2n花粉的发生率;大部分品种观赏海棠与国光苹果有较强的杂交亲和力,坐果率达30%以上,高于红星,可作为苹果杂交育种亲本使用。     

Estimation of relative water use among ornamental landscape species

Low water use plantings may enhance water conservation in dry landscapes. However, appropriate plant selection is hindered by the dearth of information available on the water needs of different species. A direct method of classification was tested under the hypothesis that relative water use by woody landscape species growing in 3.8 l containers would be representative of the water use of the same species in the landscape. Four species of distinctly different ecological origin (Leucophyllum frutescens, Spiraea vanhouteii, Viburnum tinus, Arctostaphylos densiflora) were chosen in order to obtain a wide range of responses, and their water use was measured in plants growing in 3.8 l containers and compared to that of the same species growing in drainage lysimeters, representative of landscape conditions. Half of the plants were subjected to successive cycles of stress by withholding water after irrigation to container capacity in containers, or applying a fraction of the potential evapotranspiration in lysimeters. The good fit of the regression of average daily water use by lysimeter plants on average daily water use by container plants (R²=0.87,P<0.01) reflects the consistency of relative water use of the four species. Measurement of water use at the end of nursery production may be useful for predicting the relative water use of various species after establishment in the landscape.     

A scheme for commercial propagation of ornamental plants by tissue culture

The use of tissue culture for cloning ornamentals is expensive and presently limited to a certain number of species. However, the introduction of some additional new techniques may possibly reduce the cost and broaden the range of plants that can be propagated economically in vitro. In this report, a survey is given of the methodology followed in our laboratory and its adaptation to commercial practices.Stock plants are grown under controlled conditions prior to in vitro culture in order to obtain healthier explants and uniform response (stage 0). After the establishment of aseptic cultures (stage I), buds are propagated (stage II), and are then prepared to harvest uniform cuttings (stage IIIa). Those cuttings are rooted under in vivo conditions (stage IIIb).     

日本樱花品种观赏性状多样性考察

日本樱花的原始分布种即野生种通常认为有9种：‘山樱’、‘大山樱’、‘霞樱’、‘江户彼岸’、‘丁子樱’、‘深山樱’、‘大岛樱’、‘豆樱’、‘高岭樱’。无论来自哪个种，凡山野自生的品种称为山樱。种间杂种、野生种的突然变异形成的品种、人工育成品种等统称为里樱。现有品种估计500个左右，观赏性状多样性丰富，双季花品种约有十数个。花瓣数量在60枚以上的菊(瓣)樱品种30余个，其中300枚以上的品种4个。黄色或绿色品种6个。芳香品种总数约30个左右，多数来自‘大岛樱’系统。垂枝型品种20个左右，曲枝型品种2个。自主选育适合地方风土条件的优良品种，形成性状互补的品种群体，是我国樱花产业健康、可持续发展的基础条件。     

Morphological analysis to identify the pollen parent of an ornamental interspecific hybrid eucalyptus

Eucalyptus ‘Urrbrae Gem’ is an attractive amenity tree which is believed to be a spontaneous F₁ hybrid with Eucalyptus erythronema var. erythronema the known female parent. Previous observations based on adult morphology led to suggestions that either E. gomphocephala or E. stricklandii could be the male parent. Multivariate analysis of 54 adult morphological characters placed E. ‘Urrbrae Gem’ between E. erythronema var. erythronema and E. stricklandii, with minimum spanning tree values of 0.21 and 0.27, respectively. Controlled hybridisation between E. erythronema var. erythronema and both E. stricklandii and E. gomphocephala were undertaken, and the resulting seedlings were compared to each other, and to open pollinated seedlings of the putative parent species and of the F₁ and second generation E. ‘Urrbrae Gem’ trees. Based on 14 morphological characters, seedlings clustered into eight groups, with E. erythronema var. erythronema × E. stricklandii seedlings most similar to open pollinated seedlings of the F₁ and second generation E. ‘Urrbrae Gem’ trees. In contrast, E. erythronema var. erythronema × E. gomphocephala seedlings clustered into a number of groups, with the majority close to E. gomphocephala open pollinated seedlings. The results indicated that E. stricklandii is the male parent of E. ‘Urrbrae Gem’.     

桂林植物园苦苣苔科观赏植物及其园林应用

苦苣苔科观赏植物是近年来国际上较为流行的观赏花卉。我国苦苣苔科植物资源丰富,类型众多,对其观赏价值的开发基本是一片空白。本文对桂林植物园苦苣苔科观赏植物资源、生态习性、生物特性及园林应用种类进行了论述,并对其在园林中的应用作了初步的探讨。     

常见易混淆园林植物的识别

在园林绿化工程中很可能因不能准确识别植物种类而造成工程质量不符合合同要求,从而带来巨大损失。工程中出现品种混乱的原因很多,文章着重论述华中地区一些常见易混淆园林植物的分辨要点。     

Interspecific hybridization in vanilla and molecular characterization of hybrids and selfed progenies using RAPD and AFLP markers

Vanilla, Vanilla planifolia Andrews, is native to Mexico and Central America, but is now cultivated in other parts of the tropics. Continuous clonal propagation has resulted in very little variability for crop improvement programmes in vanilla. In this study, an attempt has been made to increase the spectrum of variation by interspecific hybridization with Vanilla aphylla, an Indian species which is tolerant to Fusarium. Interspecific hybrids were successfully produced and morphological characters and molecular profiles revealed the true hybridity of the progenies. Ten seedling progenies of V. planifolia, and four interspecific hybrids obtained from crosses between V. planifolia (female) and V. aphylla (male) using a number of different loci as markers were evaluated and 319 amplified fragment length polymorphisms (AFLPs) and 83 random amplified polymorphic DNAs (RAPDs) loci were marked. The profiles indicate similarity between the parents, selfed progenies and interspecific hybrids and that all the progenies tested were variable when compared to each other, which can be exploited for crop improvement in vanilla. This is the first report in vanilla, indicating that RAPD and AFLP profiles coupled with morphological characters can be utilized to assess the variability and hybrid nature of genotypes and of successful interspecific hybridization and production of hybrids between V. planifolia and V. aphylla.     

部分栽培葱属植物叶绿体基因组的RAPD分析

  提取我国栽培的几种主要葱属植物的叶绿体DNA , 利用RAPD 技术进行遗传关系分析。从56 个10 bp 随机引物中筛选出18 个多态性引物进行扩增分析, 14 个材料共扩增出270 条带, 其中246 条具多态性。UPGMA 聚类将供试葱属品种分成4 个组。葱属在进化上存在两个方向, 分别形成了管状叶和扁平叶两种类型。     

Direct somatic embryogenesis and plant regeneration from leaf cultures of ornamental species of Dianthus

Protocol for direct somatic embryogenesis from leaf explants of economically important species of Dianthus, viz. D. caryophyllus, D. barbatus and D. chinensis has been developed. Murashige and Skoog’s (MS) liquid medium supplemented with 2,4-D (1 mg/l) was used for direct induction of somatic embryogenesis without an intervening callus phase. Initially globular structures were observed after 21 days of culture of leaf explants in liquid medium. Development of embryos to heart and torpedo stages was achieved in the liquid medium incorporated with polyethylene glycol (PEG 6000) at a concentration of 2.5%. Embryo maturation was further promoted by addition of casein hydrolysate (CH) (200 mg/l) in MS liquid medium. Embryos germinated to form plantlets on solid MS medium supplemented with GA₃ (1 mg/l). Regenerated plants with well-developed root and shoot systems were successfully transferred to field conditions.     

植物调节剂对菊花观赏性状及相关特性的影响

以菊花优良品种冈玉为实验对象,分别用300 mg/kg、600 mg/kg、900 mg/kg(毫克/公斤)浓度的植物调节剂(比久)溶液作叶面喷施,以清水为对照.结果表明:植物调节剂(比久)能使菊花株型矮化,根系发达,叶绿素含量提高,推迟花期,延长花时,增加花数,提高了菊花的观赏价值.     

草莓微繁殖苗光合特性研究

以草莓品种全明星和丰香的微繁殖一代苗和二代苗为材料,在日光温室中系统地比较了草莓微繁殖苗和普通苗在光合特性和光合色素质量分数的差异。结果表明,2种性质的微繁殖苗的净光合速率和气孔导度都显著高于普通苗;微繁殖苗的光饱和点和补偿点低于普通苗,其中全明星的一代苗与普通苗差异显著,而丰香的一代苗和二代苗与普通苗差异均显著。在表观量子效率上,微繁殖苗显著高于普通苗。微繁殖苗的叶绿素b质量分数显著高于普通苗;微繁殖苗光合速率的日变化规律与普通苗相似。     

茖葱资源评价初步研究

为选育优质的茖葱品种,本文以七个表型的茖葱为试验材料,测定其形态指标、光合特性指标及品质指标。结果表明:表型7茖葱叶产量高,可溶性蛋白质、游离氨基酸含量最高;表型5总产量高,还原糖,可溶性糖含量最高;表型2维生素C含量最高。     

Enhancing plant diversity and mitigating BVOC emissions of urban green spaces through the introduction of ornamental tree species

Promoting the plant diversity of urban green spaces is crucial to increase ecosystem services in urban areas. While introducing ornamental plants can enhance the biodiversity of green spaces it risks environmental impacts such as increasing emissions of biogenic volatile organic compounds (BVOCs) that are harmful to air quality and human health. The present study, taking Qingdao City as a case study, evaluated the plant diversity and BVOC emissions of urban green spaces and tried to find out a solution to increase biodiversity while reducing BVOC emissions. Results showed that: (1) the species diversity and phylogenetic diversity of trees in urban green spaces were 22% and 16% lower than rural forest of this region; (2) urban areas had higher BVOC emission intensity (2.6 g C m⁻² yr⁻¹) than their rural surroundings (2.1 g C m⁻² yr⁻¹); (3) introducing the selected 11 tree species will increase 15% and 11% of species diversity and phylogenetic diversity, respectively; and (4) the BVOC emissions from green spaces will more than triple by 2050, but a moderate introduction of the selected low-emitting trees species could reduce 34% of these emissions. The scheme of introducing low-emitting ornamental species leads to a win–win situation and also has implications for the sustainable green space management of other cities.     

Pre-conditioning ornamental plants to drought by means of saline water irrigation as related to salinity tolerance

This study examines the feasibility of using saline irrigation water for commercial pot cultivation of three ornamentals: Calceolaria hybrida, Calendula officinalis and Petunia hybrida. Two saline treatments were assayed: irrigation with low saline tap water (electrical conductivity = 1.16 dS m⁻¹), and irrigation with a high saline solution of NaCl 100 mM + CaSO₄ 10 mM + MgSO₄ 2.5 mM (electrical conductivity = 12.5 dS m⁻¹). When the control plants reached marketable size the watering was stopped and the plant response to drought was studied. Petunia and Calceolaria were tolerant to salinity. Petunia saline-treated plants reduced their growth slightly and increased N and chlorophyll contents in the leaves. Calceolaria experienced a strong reduction in growth and a delay in flowering but no toxicity symptoms or mortality was recorded. These species were moderate NaCl accumulators. Calendula was sensitive to salinity: 16% of the plants died and the surviving ones experienced a heavy reduction of growth, a decrease in chlorophyll and a large accumulation of NaCl in the leaves. Saline pre-conditioned plants of Calceolaria and Petunia were tolerant to drought. In these plants, leaf water content and, specifically, leaf relative water content were sustained longer than in non-pre-conditioned plants throughout the drought period. In Calendula, leaf relative water content decreased at the same rate in pre-conditioned and non-pre-conditioned plants. Consequently, salinization did not confer drought resistance upon this species. Possible factors determining the tolerance to drought in saline pre-conditioned plants are discussed.