The preparation in vitro of chrysanthemum for transplantation to soil

Plantlets of Dendranthema grandiflora Pennine Reel were grown from nodal sections on Sorbarods saturated with liquid medium containing 0–3 mg 1^–1 of various growth retardants. After 4 weeks they were transferred to compost and maintained at a relative humidity of 42% at 27.5°C. Wilting was assessed over a period of 3 h. Plantlets treated with paclobutrazol, flurprimidol, triapenthenol, chlorphonium chloride, uniconazol and ancymidol showed dose-related reductions in wilting up to a concentration of 3 mg 1^–1. Responses to tetcyclacis and mepiquat chloride were weaker, and no responses to chlormequat chloride, BTS 44584 or diaminozide could be detected. These observations are compatible with an hypothesis that resistance to wilting derives from inhibited synthesis of gibberellins.     

国产五种菊属植物的核型研究

本文对国产5种菊属植物的核型进行了研究,结果为:D. indicum 2n=2x=18=16m 2st,2n=4x=36=28m 6sm 2st;D. lavandulifolium 2n=2x=18=14m 4sm,2n=4x=36=28m 6sm 2st;D. lavandulifolium var.seticuspe 2n=2x=18=12m 6sm;D. chanetii 2n=4x=36=20m 14sm 2st,2n=6x=54=38m 14sm 2st;D. potentilloides2n=2x=18=14m 2sm 2st;D. vestitum 2n=6x=54=38m 16sm.核型分析的结果表明,本文所研究类群中出现的多倍体多为异源多倍体;根据对核型资料、形态特征及地理分布特点的综合分析,作者认为多倍化是菊属野生种进行的主要途径。     

神农香菊干花净油成分的研究

神农香菊全草提取的香浸膏香气浓郁独特,可用于调配多种高档化妆用香精,也可直接用于饮料中,在香精香料工业中具有较大的实用价值。本文首次报告了我们用毛细管气相色谱仪和色谱/质谱/计算机联用分析仪,对神农香菊干花净油成分进行分析的初步结果。鉴定出的已知成分包括脂肪族类,含氧或非含氧的单萜及倍半萜类化合物32个。     

Agrobacterium rhizogenes mediated induction of apparently untransformed roots and callus in chrysanthemum

The agropine type Agrobacterium rhizogenes strain LBA9402 induced callus and roots on stems of greenhouse grown plants and on leaf disks of in vitro grown plantlets of chrysanthemum (Dendranthema grandiflora Tzvel.). In this callus and roots no opines were detected, nor were any of the other features of the hairy root syndrome observed. Experiments aimed to identify the nature of the tumour-like growth revealed that induction was correlated with the presence of the TR-DNA on the Ri-plasmid. Root induction was probably the result of auxin synthesis following transient expression of iaaM and iaaH genes, present on the TR-DNA. The chrysanthemum cultivar used, cv. Parliament, showed a high auxin sensitivity compared to tobacco. Analysis of early transformation events using the GUSintron reporter gene revealed that low efficiency gene transfer and transient gene expression took place, but most probably without stable integration of the T-DNA in the plant genome. The results presented here stress the fact that callus formation or root induction as measures for transformation efficiency should be used with caution.     

Density, dispersal, and feeding impact of western flower thrips (Thysanoptera: Thripidae) on flowering chrysanthemum at different spatial scales

Abstract.  1. This study evaluated the effect of dispersal on the density and feeding impact of a phytophagous insect in relation to the spatial distribution of its host plants.
2. The interaction between density, dispersal, and feeding impact of western flower thrips on flowering chrysanthemum was quantified at three spatial scales, with infested and uninfested plants either isolated in 0.25 m² individual cages, or enclosed together in 2.25 m² communal cages or 75 m² greenhouses.
3. In individual cages, the rate of dispersal from chrysanthemum plants to blue sticky traps increased with the density of thrips for females but not males. Uninfested plants consistently had fewer thrips when they were individually caged rather than enclosed with plants infested with adults, indicating that dispersal mediates inter-plant distribution of thrips.
4. The feeding impact of thrips on inflorescences was evaluated using the absorbance of ethanol extracts at wavelengths characteristic of yellow carotenoid pigments associated with chrysanthemum inflorescences (415, 445, and 472 nm). Increasing absorbance of extracts with increasing density of thrips per inflorescence suggests that feeding by thrips results in ruptured cells leaching carotenoid pigments.
5. In communal cages, the distribution of thrips was uniform for infested and uninfested plants, whereas the density and feeding impact of thrips in greenhouses were higher for infested than uninfested plants. These results suggest that short-range dispersal by adults homogenises the density and feeding impact of thrips among host plants only on a small spatial scale.     

菊花病虫害综合防治研究

系统调查鉴定了菊花病毒病、霜霉病、叶斑病、叶面害虫、蚜虫天敌种类及其流行规律,研究了组培脱毒苗、地膜覆盖移栽、与高秆作物套作、摘顶稍、利用昆虫天敌及化学防治等综合治理效果.测定了农药残留量.结果表明,菊花组培苗脱毒率在60%左右,脱毒苗增产50%以上,叶枯病、霜霉病病叶率下降28%～30%,虫口密度下降40%,在收菊花前1个月使用拟菊酯杀虫剂,农药残留量低于允许值,不会对菊花和环境造成污染.     

A protoplast to plant system for the chrysanthemum Dendranthema zawadskii x D. grandiflora

Summary Plantlets were regenerated from protoplasts of in vitro shoot cultures and leaf-derived de novo shoots of the chrysanthemum Dendranthema zawadskii x D. grandiflora. Isolated protoplasts reformed cell walls and then began to divide within 24 hours of culture in streaky plate agarose lenses surrounded by liquid V-KM medium. Twenty one days after isolation, 1 mm diameter callus clumps were transferred to shoot regeneration medium. After a further 33 days leaves became visible. Elongated shoots were rooted on half strength hormone-free MS medium.Abbreviations BAP 6-benzylaminopurine - IAA 3-indoleacetic acid - MS Murashige and Skoog (1962) - NAA 1-naphthylacetic acid - Pfr Photon fluence rate - V-KM Binding and Nehls (1977)     

<Emphasis Type="Italic">In vitro</Emphasis> selection and regeneration of chrysanthemum (<Emphasis Type="Italic">Dendranthema grandiflorum</Emphasis> Tzelev) plants resistant to culture filtrate of <Emphasis Type="Italic">Septoria obesa</Emphasis> Syd

Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About 30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates.     

中国菊属一些种的分支分类学研究

运用分支分析方法研究了12种原产中国的野生菊属植物的系统发育关系,并引入了若干栽培品种及部分杂种一代植株作为分析材料。研究结果表明：分支分析方法有效而准确地将分类群分类,并揭示出毛华菊（Dendranthemarestitum）与菊花（Dendranthema×gran-diflorum）同为菊属植物中进化程度较高的种,部分种间杂种也已进入栽培类群。同时还发现不同性状在各品种间平行进化的现象。根据上述结果,作者讨论了中国菊属植物的系统进化及菊花起源问题。     

Influences of fertilization on Aphis gossypii and insecticide usage

Abstract: Fertilization levels for ornamental crops may influence pest population dynamics, crop quality, and pest management strategy. We examined the effect of fertilization on population growth and within‐plant distribution of melon or cotton aphid, Aphis gossypii Glover, on potted chrysanthemum, Dendranthema grandiflora (Tzvelev). In terms of pest management implications, we also investigated the effect of fertilization on the number of insecticide applications needed to control A. gossypii on potted chrysanthemum. Population growth rate of A. gossypii increased with fertilization levels from 0 to 38 ppm N and reached a plateau from 38 to 488 ppm N. Increased fertilization beyond 38 ppm N, 10% of the commercial standard, did not result in higher aphid number. Aphids responded to nutrient availability of plants by distributing themselves in areas with higher level of nitrogen. More aphids were found in the apical and middle strata of the plants than the basal stratum, which had the lowest nitrogen content. Leaf nitrogen content increased with increased fertilization level and was consistently higher in the apical and middle strata than the basal stratum. Increased fertilization from 0 to 375 ppm N did not result in higher number of insecticide applications. All three insecticides (bifenthrin, kinoprene or pymetrozine) were effective in keeping the aphid infestation below a pre‐determined level, five aphids per plant, but pymetrozine required the least number of applications. For chrysanthemum, a fast‐growing crop and heavy utilizer of nitrogen, increased fertilization shortened the time to flowering, which would allow growers to harvest their crop sooner and reduce the time for aphid population growth. Reduction in time to harvest could result in significant reduction of insecticide usage by reducing the time for aphid population growth. As a result, high fertilization together with minimal runoff may be a useful tactic to an integrated pest management (IPM) programme for managing A. gossypii on potted chrysanthemums.