Rapid mass propagation of Chrysanthemum cinerariaefolium Vis. by callus culture and ability to synthesise pyrethrins

 Rapid mass propagation of Chrysanthemum cinerariaefolium from young flower heads was developed to compare the ability of callus, in vitro shoots and rooted plants, and original plants to synthesize pyrethrins. The ability to synthesise all six pyrethrin components increased with differentiation. Jasmolin II and cinerin II were the main products present in mother plant shoots, whereas pyrethrin I was the greater component present in callus and in vitro plants. Clonal propagation increased the pyrethrin I content compared to that of plant shoots and young flowers. Total pyrethrin content was the same in in vitro and plant shoots, but lower in these shoots than in young flowers. The pyrethrin I/pyrethrin II ratio, which is directly related to insecticidal activity, varied from 3.4 in in vitro shoots to 0.87 in mother plant shoots and young flowers. Received: 11 July 1998 / Revision received: 10 March 1999 / Accepted: 12 April 1999     

Chemical Diversity of the Natural Populations of Dalmatian Pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch.Bip.) in Croatia

Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevir. ) Sch.Bip. ) is a plant species endemic to the east Adriatic coast. The bioactive substance of Dalmatian pyrethrum is a natural insecticide, pyrethrin, a mixture of six active components (pyrethrins I and II, cinerins I and II, and jasmolins I and II). The insecticidal potential of pyrethrin was recognized decades ago, and dried and ground flowers have traditionally been used in Croatian agriculture and households. A total of 25 Dalmatian pyrethrum populations from Croatia were studied to determine the pyrethrin content and composition, and to identify distinct chemotypes. The total pyrethrin content ranged from 0.36 to 1.30% (dry flower weight; DW) and the pyrethrin I/pyrethrin II ratio ranged from 0.64 to 3.33%. The statistical analyses revealed that the correlations between the percentage of pyrethrin I and of all the other components were significant and negative. The total pyrethrin content was positively correlated with the percentage of pyrethrin I and negatively correlated with cinerin II. The multivariate analysis of the chemical variability enabled the identification of five chemotypes among 25 Dalmatian pyrethrum populations. The chemical characterization of indigenous Dalmatian pyrethrum populations may serve as a good background for future breeding and agricultural exploitation.     

Pyrethrin accumulation in elicited hairy root cultures of <Emphasis Type="Italic">Chrysanthemum cinerariaefolium</Emphasis>

The flowers of Pyrethrum (Chrysanthemum cinerariaefolium) are known to contain Pyrethrins that are naturally occurring potential insecticide. Hairy roots were induced from leaves of C. cinerariaefolium using Agrobacterium rhizogenes strain A4. The root clones were characterized in to four groups i.e. thick, unbranched (D2 and D5), thin, highly branched (D3), thick, branched (B2) and thick, highly branched (D1, D6). Six established hairy root clones showed the presence of pyrethrin and were selected for elicitation studies. Growth kinetics studies revealed highest growth index in hairy root clone D1 (592.0) followed by D6 and D3 on dry weight basis after 40 days of culture. The maximum pyrethrin content was found in the clone D3 (7.2 mg/g dw) which is comparable to the flowers obtained from the variety “Avadh”. Hairy root clone D2 (5.2 mg/g dw) and D6 (1.3 mg/g dw) contained pyrethrin but in less amount as compared to clone D3. The PCR analysis showed the presence of rol B and rol C genes in all the six hairy root clones while rol A was detected only in D2 clone. The methanolic extract of D3 clone showed antifungal activities against phytopathogenic fungal strains which were found maximum against Curvuleria andropogonis followed by Colletotrichum acutatum and Rhizoctonia solani. Hairy root clones D2, D3 and D6 were elicited with culture filtrate of endophytic fungus (Fusarium oxysporum) and bacteria (Bacillus subtilis). The culture filtrate (4.0?%v/v) of both the fungal and bacterial origin was found to be effective in enhancing the pyrethrin content in all the tested hairy root clones. Clone D3 showed maximum pyrethrin content on elicitation with F. oxysporum (9.7 mg/g dw) and B. subtilis (9.7 mg/g dw) culture filtrate, which is 32?% higher than the non elicited D3 hairy roots (7.2 mg/g dw). F. oxysporum also enhanced the hairy root growth resulting into the higher biomass yield of D3 (50?%) and D2 (76?%) in comparison to control non elicited hairy root clones of D3 and D2, respectively leading to higher pyrethrin yield.     

三种植物源药剂对红火蚁的防治效果评估及其对本地蚂蚁群落影响

红火蚁Solenopsis invicta Buren是一种危险性入侵害虫,可对人类健康、农林业生产、公共安全和生态系统产生严重的负面影响。目前,化学农药是防治红火蚁的主要方法。然而,大多数化学农药并不适用于有机农场、水产养殖区等生态敏感区。为筛选出用于生态敏感区红火蚁防治的药剂,本文结合室内和田间试验评估了植物源杀虫剂苦参碱Matrine、鱼藤酮Rotenone和除虫菊素Pyrethrin对红火蚁的防治效果。室内试验结果表明,苦参碱、鱼藤酮和除虫菊素对红火蚁均具有较高的毒性。田间试验表明,25.00 mg/L和12.50 mg/L苦参碱、250.00 mg/L 和125 mg/L鱼藤酮、75.00 mg/L和37.50 mg/L除虫菊素灌巢处理,红火蚁蚁巢减退率分别达到100%、81.25%、87.50%、79.17%、71.73%和66.67%。然而,除25.00 mg/L苦参碱外,其他处理均导致在被灌巢的蚁巢周围短期内出现新蚁巢。灌巢处理后,处理区的蚂蚁多样性指数和均匀度指数升高,优势度指数下降。综上所述,苦参碱、鱼藤酮和除虫菊素适合灌巢处理防治红火蚁,其中0.5%苦参碱可溶性液剂能有效降低红火蚁种群数量,使得蚁巢减退率达100%,同时对本地蚂蚁群落没有负面影响,因此该商品制剂在红火蚁防治方面具有较好的开发潜力。     

Identification and characterization of a GDSL lipase-like protein that catalyzes the ester-forming reaction for pyrethrin biosynthesis in Tanacetum cinerariifolium- a new target for plant protection

Although natural insecticides pyrethrins produced by Tanacetum cinerariifolium are used worldwide to control insect pest species, little information is known of their biosynthesis. From the buds of T. cinerariifolium, we have purified a protein that is able to transfer the chrysanthemoyl group from the coenzyme A (CoA) thioester to pyrethrolone to produce pyrethrin I and have isolated cDNAs that encode the enzyme. To our surprise, the active principle was not a member of a known acyltransferase family but a member of the GDSL lipase family. The recombinant enzyme (TcGLIP) was expressed in Escherichia coli and displayed the acyltransferase reaction with high substrate specificity, recognized the absolute configurations of three asymmetric carbons and also showed esterase activity. A S40A mutation in the Block I domain reduced both acyltransferase and esterase activities, which suggested an important role of this serine residue in these two activities. The signal peptide directed the localization of TcGLIP::enhanced green fluorescent protein (EGFP) fusion, as well as EGFP, to the extracellular space. High TcGLIP gene expression was observed in the leaves of mature plants and seedlings as well as in buds and flowers, a finding that was consistent with the pyrethrin I content in these parts. Expression was enhanced in response to wounding, which suggested that the enzyme plays a key role in the defense mechanism of T. cinerariifolium.     

The pollination ecology of Paraboea rufescens (Gesneriaceae): a buzz-pollinated tropical herb with mirror-image flowers

BACKGROUND AND AIMS: Gesneriaceae is a pantropical plant family with over 3000 species. A great variety of pollination mechanisms have been reported for the neotropical members of the family, but the details of buzz-pollination and enantiostyly for the family have not been described. We investigated the floral biology and pollination ecology of Paraboea rufescens in Xishuangbanna, south-west China, considering three aspects: (1) the type of enantiostyly exhibited; (2) whether the species is self-compatible; and (3) whether pollinator behaviour could enhance the precision of pollen transfer between flowers of contrasting stylar orientation. METHODS: Flowering phenology was monitored once a month during vegetative growth, and once a week during flowering both in the field and under cultivation. Pollination manipulations and pollinator observation in the field were conducted. KEY RESULTS: Anthesis occurred early during the morning, and flowers remained open for 1-5 d, depending on weather conditions. Controlled pollinations revealed that P. rufescens is self-compatible, and exhibited inbreeding depression in seed set. Plants were pollinator limited in natural populations. The similar stylar deflection among flowers within a plant limits autonomous self-pollination as well as pollination between flowers. Two species of bumble bees (Bombus spp.), Amegila malaccensis and Nomia sp. effectively pollinated P. rufescens. These pollinators visited flowers in search of pollen with almost the same frequency. None of the pollinators appeared to discriminate between left- or right-handed flowers. CONCLUSIONS: Paraboea rufescens exhibits monomorphic enantiostylous flowers and a buzz-pollination syndrome. Floral morphology in P. rufescens and pollinator foraging behaviour seems likely to reduce self-pollination and pollinations between flowers of the same stylar deflection.     

罗汉果雄株不足、花期不遇研究

<正> 罗汉果为雌雄异株植物,栽培品种均需人工授粉才能结实。当前,区内外罗汉果生产上,普遍存在着雄株不足,花期不遇的问题,新区更为严重,给生产带来严重的损失,成为目前急待解决的问题。 1981年以来,在科委、外贸,供销等部门大力支持下,我们通过新老产区雄株生长情况、     

Nymphal performance correlated with adult preference for flowering host plants in a polyphagous mirid bug, Apolygus lucorum (Heteroptera: Miridae)

Apolygus lucorum (Heteroptera: Miridae), a polyphagous mirid bug, often shows a strong preference for flowering host plants. It is hypothesized that host plant selection by phytophagous insects results in a variety of behavioral trade-offs. In this study, the relationship between adult preference and nymphal performance was examined on host plants with their flowers left intact and with flowers removed to investigate potential trade-offs in A. lucorum’s preference for flowering plants. Field trials in 2010 and 2011 showed that adults and nymphs were significantly more abundant on plants with flowers left intact than on those with flowers removed, while oviposition choice trials in field cages revealed that female adults preferred to lay eggs on plants with flowers. Laboratory performance trials demonstrated that adult lifespan and fecundity and nymphal development rate and survival were all significantly higher on plants with flowers compared with plants without flowers. In contrast, sex ratio was not significantly different. Simple linear regression analysis showed positive correlations between (1) adult and nymphal abundances in the field, (2) nymphal development rates and survival with adult fecundity in the laboratory, and (3) adult lifespan with fecundity in the laboratory. Since a positive preference–performance correlation was found for A. lucorum, we conclude that there are no evident behavioral trade-offs for host plant selection by this polyphagous mirid bug.     

THE BALANCE BETWEEN CHASMOGAMY AND CLEISTOGAMY IN COLLOMIA GRANDIFLORA (POLEMONIACEAE)

The extent of cleistogamy (CL) and chasmogamy (CH) was investigated in natural populations of Collomia grandiflora Dougl. ex Lindl. The ubiquitous occurrence of CL flowers was documented in 18 populations from throughout the geographic range of the species. The interrelationship of environmental perturbation, vegetative weight, and the balance between CH and CL flowers was investigated by means of a factorial experiment which varied plant density, incident light and soil mix. An ANOVA revealed that total plant weight increased significantly under conditions of low density, low light and low sand content, with density accounting for most of the variance in plant weight. Interactions involving density were not significant. The number of CH and CL flowers and estimated percent outcrossing increased significantly with increased plant weight, low density, low light, and low sand content, although an analysis of covariance showed that plant weight and density accounted for most of the variance in these traits. Among large, multibranched plants, the proportion of CL flowers increased in a basipetal pattern, whereas most of the CH flowers were restricted to the terminal and upper inflorescences. The smallest plants produced only a single terminal inflorescence comprising entirely CL flowers. The proportion of reproductive effort allocated to outcrossing was dependent upon plant size as estimated from total weight, whereas the proportion allocated to ***selfing was relatively independent. Studies of outcrossed vs. inbred progenies of five populations revealed little evidence for immediate inbreeding depression with respect to plant weight and the number of CH or CL flowers, but indicated that significant quantitative genetic differences exist for these traits among populations of diverse ecological or geographical origin.     

Evaluation of radical scavenging potential and total phenol content in Woodfordia fruticosa from different altitudes

Woodfordia fruticosa Kurz is a member of family Lythraceae, commonly used in the treatment of diseases like leucorrhoea, dysentery, leprosy and menorrhagia. The plant material such as leaves, bark and flowers were collected from three different (200, 402 and 600?m) altitudes of Khandala (M.S. India) and the extracts were prepared in solvents like methanol, ethanol and distilled water. The radical scavenging potential and total phenolic content of the extracts were evaluated. The methanol extract of bark collected from the location one (200?m) showed high radical scavenging activity (96.52?±?0.02) than distilled water and ethanol extracts (57.80?±?0.2 and 86.52?±?0.03). The bark of the plant showed highest (663?±?37.85) total phenolic content that of flowers and leaves. The methanol extracts of leaves, bark and flowers showed high tannic acid content, while TBARS assay of ethanol extract of flowers showed maximum protection (27.65). It was observed that there is no significant difference in percent scavenging activity in different plant parts collected from three different altitudes but showed difference in the solvent system used. The results obtained are in support of extensive use of Woodfordia fruticosa in traditional medicine and endorses the use of bark, while it needs further investigations on the plants growing in different geographic areas.     

Remote perception of floral nectar by bumblebees

Summary On both artificial flowers in the laboratory and certain plant species in the field, bumblebees often closely approached flowers and then departed without probing for nectar. In laboratory experiments where nectar rewards were associated with subtle visual or olfactory cues, bumblebees approached and avoided non-rewarding flowers. Flowers that bees entered and probed for nectar contained rewards much more frequently than predicted by chance alone. When there were no external cues associated with nectar content, bees visited rewarding flowers by chance alone, provided rewarding flowers were not spatially clumped. In the field, bumblebees approached and rejected a large proportion of dogbane flowers and red clover inflorescences. On both species, flowers or inflorescences probed by bees contained more nectar than those rejected by bees or those that I chose at random. On fireweed and monkshood, bees rarely or never approached and rejected healthy-looking flowers. Predictions generated by an optimal foraging model were tested on data from four bumblebee species foraging on red clover. The model was highly successful in qualitatively predicting the relationship between handling time and proportion of inflorescences rejected by individual bees, and the relationship between threshold nectar content for acceptance by bees and average resource availability. Thus, bees appeared to use remotely perceived cues to maximize their rates of nectar intake.     

Light effects on pyrethrum shoot cultures

Light consistently increased the pyrethrin content of pyrethrum shoot organ cultures. Under the experimental conditions used, the pyrethrin increase was not dependent upon a constant light supply.     

Sugar Composition of Nectars and Fruits Consumed by Birds and Bats in the Tropics and Subtropics1

Several characteristics of flowers and fruits have been suggested as comprising syndromes of characters that indicate particular classes of pollinators and fruit dispersers. Common phylogenetic history among species, however, may also significantly influence these characters and obscure or enhance perceived patterns of plant syndromes. We analyzed the proportions of glucose, fructose, and sucrose by paper chromatography in the nectar and fruit juice of 525 tropical and subtropical plant species to test whether sugar chemistry was correlated with volant vertebrate pollinator or fruit disperser classes. Samples were taken from Old World and New World species and the calculations kept separate. Kruskal-Wallis tests of family means showed significant deviations in the percent sucrose content among pollinatorl disperser classes. Mann-Whitney U-tests showed significant differences among nectars of all pollinator classes but fruit juices differed only due to the high sucrose content of megachiropteran dispersed fruits. In addition, sign tests of samples occurring within families showed significant correlations between percentage sucrose content and pollinator/disperser classes. Passerine nectars had low sucrose content. In striking contrast, the nectar of hummingbird flowers had very high sucrose content. The Microchiroptera nectars showed hexose richness with a sucrose content somewhat greater than that of passerine flowers. Megachiroptera flowers showed sucrose-rich nectars. The results for fruits were comparable to those for nectars. Passerine fruits were hexose dominated, microchiropteran fruits had a sucrose content similar to passerine fruits, and megachiropteran fruits were sucrose-rich. We speculate on the evolutionary sequence of changes in nectar and fruit juice sugar composition and suggest that future investigations consider the chemistry of other food sources such as pollen and leaves. Only with these additions and other ecological studies can the full interplay of such plant-animal interactions be anticipated.     

A film technique for the biological evaluation of pyrethrum-in-oil insecticides for use against stored product insects in warehouses

There is need for a technique whereby a given insecticidal preparation can be compared with a standard containing 0.8% (w/v) pyrethrin 1 in a heavy white oil and pronounced biologically equal or inferior to the standard within known and reasonable limits. A film method was investigated, Tribolium castaneum beetles being used as the test insects.
Numerous factors which may influence the kill achieved are discussed. The results of preliminary work, planned to help in the standardization of some of these factors, are summarized.
Several materials were tested to ascertain their suitability for reception of the insecticidal film and, as thin greaseproof paper showed promise, its possibilities were explored. Although 0.3 % pyrethrin I could be distinguished from 0.4%, 0.5% could not be distinguished from 0.8%, and the results throughout were very heterogeneous.
Woven Nylon proved more satisfactory, since the test just failed to establish a significant difference between 0.6 and 0.8% pyrethrin 1. The origin of a pink coloration of the substrate, when T. castaneum beetles were confined on Nylon sprayed with pyrethrum in oil, was investigated.
Whatman filter paper no. 544 proved the best substrate, and a comparative test on it will distinguish 0.65% pyrethrin 1 from the standard 0.8%; the limit could probably be raised to 0.7%.
The influence of several factors on the homogeneity of the results was investigated, and the importance was shown of allowing beetles time to recover from the mechanical shock inherent in the method of counting into batches.
Directions are given for carrying out the film technique for comparing preparations of relatively high pyrethrin content. The method does not measure the direct spray or fumigant action of the insecticide.
The technique described is compared with the Peet-Grady method for evaluating liquid household insecticides of low pyrethrin content. A simplified, but less accurate, design for the test is indicated.     

How long to stay on a plant: the response of bumblebees to encountered nectar levels

This field study shows that the number of flowers visited per bee per plant (Anchusa officinalis) increases with the instantaneous nectar level at the plant. Observations during the season showed that a bee visits more flowers per plant of given nectar level, the lower the overall mean nectar level in the study area. These results agree with predictions from a model based on the ‘marginal value theorem’, but with assumptions and constraints adapted for nectar-foraging bees. It suggests that bumblebees assess the nectar level at a plant by sampling one or a few flowers, which is possible because within-plant nectar volumes are correlated. The bees compare encountered gains to an optimal plant switching threshold equal to the overall mean nectar level and leave an unrewarding plant as soon as possible, but continue to visit the flowers on a rewarding plant. However, the bees leave before having visited all flowers due to a searching constraint. The bees’ response to plant nectar levels results in systematic flower visitation, because visitation to recently depleted flowers is reduced, which reduces the variation of the inter-visit time per flower. Systematic flower visitation implies that the overall mean encountered gain per flower is higher than the overall mean standing crop, as predicted by a model of systematic foraging. However, the sampling and searching constraints on the bees’ response to plant nectar levels increase the variation of the inter-visit time per flower, and thereby limit the degree of systematic flower visitation and the effect on the mean encountered gain.     

Sexual dimorphism in pollen grain size in cryptically dioecious Thalictrum macrostylum

While several plant species are initially described as androdioecious, upon more thorough investigation, many of these are found to be cryptically dioecious with functionally male flowers and perfect flowers that produce inaperturate pollen or are otherwise functionally female on separate plants. The change in function of pollen produced by perfect flowers opens up the possibility for the evolution of sexual dimorphism in pollen grain size. We found that Thalictrum macrostylum (Ranunculaceae) is cryptically dioecious, and produces apparently inaperturate pollen in perfect flowers. In four field sites throughout North Carolina, inaperturate grains are larger than grains from staminate flowers and also show a greater variance in size. We also found substantial variation in pollen grain size among plants. The sites with lower soil nutrient content also had smaller pollen grains of both types, although local adaptation or genetic drift may also be causing among-site variation.     

Phytoextraction of weathered p,p'-DDE by zucchini (Cucurbita pepo) and cucumber (Cucumis sativus) under different cultivation conditions

Previous studies have shown that zucchini (Cucurbita pepo) and cucumber (Cucumis sativus) under field conditions are good and poor accumulators, respectively, of persistent organic pollutants from soil. Here, each species was grown under three cultivation regimes: dense (five plants in 5 kg soil): nondense (one plant in 80 kg soil): and field conditions (two to three plants in approximately 789 kg soil). p,p'-DDE and inorganic element content in roots, stems, leaves, and fruit were determined. In addition. rhizosphere, near-root, and unvegetated soil fractions were analyzed for concentrations of 11 low-molecular-weight organic acids (LMWOA) and 14 water-extractable inorganic elements. Under field conditions, zucchini phytoextracted 1.3% of the weathered p,p'-DDE with 98% of the contaminant in the aerial tissues. Conversely, cucumber removed 0.09% of the p,p'-DDE under field conditions with 83% in the aerial tissues. Under dense cultivation, cucumber produced a fine and fibrous root system not observed in our previous experiments and phytoextracted 0.78% of the contaminant, whereas zucchini removed only 0.59% under similar conditions. However. cucumber roots translocated only 5.7% of the pollutant to the shoot system, while in zucchini 48% of the p,p'-DDE in the plant was present in the aerial tissue. For each species, the concentrations of LMWOA in soil increased with increasing impact by the root system both within a given cultivation regime (i.e., rhizosphere > near-root > unvegetated) and across cultivation regimes (i.e., dense > nondense > field conditions). Under dense cultivation, the rhizosphere concentrations of LMWOAs were significantly greater for cucumber than for zucchini; no species differences were evident in the other two cultivation regimes. To enable direct comparison across cultivation regimes, total in planta p,p'-DDE and inorganic elements were mass normalized or multiplied by the ratio of plant mass to soil mass. For cucumber, differences in total p,p'-DDE and inorganic element content among the cultivation regimes largely disappear upon mass normalization, indicating that greater uptake of both types of constituents in the dense condition is due to greater plant biomass per unit soil. Conversely, for zucchini the mass normalized content of p,p'-DDE and inorganic elements is up to two orders of magnitude greater under field conditions than under dense cultivation, indicating a unique physiological response of C. pepo in the field. The role of cultivation conditions and nutrient availability in controlling root morphology, organic acid exudation, and contaminant uptake is discussed.     

The preparation of a standard pyrethrum extract in heavy mineral oil, with observations on the relative toxicities of the pyrethrins in oil and aqueous media

The preparation of a pyrethrum extract in highly refined heavy mineral oil, suitable for use as a basis of reference in the biological evaluation of commercial pyrethrum-heavy oil preparations, is described. The solution was standardized with respect to colour, resin content and equal proportions of the pyrethrins. A standard solution containing pyrocatechol remained stable, when judged by the chemical determination of the pyrethrins, over a period of months.
When applied in a heavy mineral oil medium, pyrethrin II was shown to possess a toxicity to Tribolium castaneum Hbst. approaching, if not equal to, that of pyrethrin 1. When applied in an aqueous medium the toxicity of pyrethrin II was very much lower than that of pyrethrin I.     

What colour of flowers do Lepidoptera prefer for foraging?

Food plant preferences of some Lepidoptera species associated with particular colour of the flowers were investigated. Based on 1,329 field observations of 43 Lepidoptera and 66 plant species, Lepidoptera showed a high tendency (G-test, G _adj = 698.6, df = 6, P < 0.001) to use the yellow (29%) and pink (28%) coloured flowers for foraging. Compared to the other colours it was evident that plants with red flowers (2%) were not preferred. Moreover, the plants with red (H = 0.435) and yellow-white (H = 0.543) flowers were not visited by diverse Lepidoptera species. Although yellow and pink flowers were most frequently visited, the highest degrees of the Lepidoptera diversity values were associated with the plants having blue (H = 0.647) and purple (H = 0.634) flowers. Species of Nymphalidae were most numerous (14 spp.) in the study area and the members of this family were observed 430 times on 39 different plant species, but never on plants with red flowers. Pieris rapae was the most abundant species that occurred 136 times on a total of 21 different plant species of which eight had yellow flowers. But, this species has never been seen while feeding on red flowers.     

多效唑和脱落酸对白兰花内源激素及光合速率的影响

以白兰花为试材,采用土施、喷施多效唑和脱落酸的方式对其植株进行处理,观察株高和开花情况,同时结合主要内源激素含量及光合特性进行分析。结果表明：经处理后,白兰花内源激素IAA、GA3、Z、ZR和ABA含量呈现不同的变化规律,且光合速率也出现明显的变化;经处理后的植株明显矮化,盛花期提前,开花数量大幅度增加,且开花次数也显著增多。其中以土施和喷施多效唑与脱落酸的效果最好,处理后的植株只有正常株高的40%～50%,开花数却达到正常植株的2.3倍。