A Novel Lateral Organ Boundary-domain Factor CmLBD2 Positively Regulates Pollen Development by Activating CmACOS5 in Chrysanthemum morifolium.

Male sterility, as a common reproductive characteristic in plants, plays an important role in breeding, in which pollen abortion is a key factor leading to male sterility. Here, based on a low expression level gene CmACOS5 in transcriptome of pollen abortive chrysanthemum, a new transcription factor CmLBD2 of the Lateral Organ Boundaries Domain family, which could bind the promoter of CmACOS5 by yeast one-hybrid library was screened. This study revealed the origin and expression pattern of CmLBD2 in chrysanthemum and verified the functions of two genes in pollen development by transgenic means. Inhibiting the expression of CmACOS5 or CmLBD2 can lead to a large reduction in pollen and even abortion in chrysanthemum. Using yeast one-/two-hybrid, electrophoretic mobility shift assays, and luciferase reporter assays, it was verified that CmLBD2 directly binds to the promoter of CmACOS5. These results suggest that LBD2 is a novel, key transcription factor regulating pollen development. This result will provide a new research background for enriching the function of LBD family proteins and also lay a new foundation for the breeding of male sterile lines and the mechanism of pollen development.

Comparison of allelopathic effects of two typical invasive plants: Mikania micrantha and Ipomoea cairica in Hainan island.

Mikania micrantha and Ipomoea cairica are two invasive plants widely distribute and seriously damage in Hainan island. In this study, the leaves extracts of two weeds were collected and determined for their allelopathic potentials on Chrysanthemum coronarium. The phytotoxicity bioassay showed that when the extract concentration was 50 and 100 mg/ml, the inhibited effects of M. micrantha on growth of C. coronarium were greater than by I. cairica. However, when the extract concertation at 400 mg/ml, the opposite inhibited effects were observed. We speculated this phenomenon was caused by different allelopathic compounds. Therefore, using gas chromatography-mass spectrometry, 19 and 23 compounds were identified respectively, benzoic acid and cinnamic acid were the main components in the two leaves extracts, which were selected to carry out the further bioassays. Subsequent bioassay results showed the effects of two allelochemicals on morphological index and chlorophyll content and POD activity were all negative to C. coronarium, whereas the content of MDA and activity of SOD, CAT represented adverse changes. Moreover, the inhibitions by cinnamic acid were generally greater than those by benzoic acid. Thus, the phenolic acids played the most crucial roles in the allelopathic effccts of M. micrantha and I. cairica leaves extracts.

The flower head of Chrysanthemum morifolium Ramat. (Juhua): A paradigm of flowers serving as Chinese dietary herbal medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Dietary herbal medicines are widely used for the prevention and treatment of a variety of diseases due to their pharmacological activities in China. Juhua (the flower head of Chrysanthemum morifolium Ramat.), the most representative flower-derived one, which is mainly used for the treatment of respiratory and cardiovascular diseases, shows significant activities, such as antimicrobial, anti-inflammatory, and anticancer, and, neuroprotective, as well as effects on the cardiovascular system. AIMS OF THIS REVIEW: This review aims to provide an overview of the crucial roles of flowers in Chinese dietary herbal medicine, and the pharmaceutical research progress of Juhua (the paradigm of dietary herbal medicine derived from the flower) including its applications in Traditional Chinese medicine and diet, cultivars, phytochemistry, quality control, pharmacology, and toxicity, along with chrysanthemum breeding and biotechnology. METHOD: The information associated with Chinese dietary herbal medicine, flower-derived medicine, dietary flower, and pharmaceutical research of Juhua, was collected from government reports, classic books of Traditional Chinese medicine, the thesis of doctors of philosophy and maters, and database including Pubmed, Scifinder, Web of Science, Google Scholar, China National Knowledge Internet; and others. RESULT: All flower-originated crude medicines recorded in Chinese pharmacopeia and their applications were summarized for the first time in this paper. The edible history and development of flowers in China, the theory of Chinese dietary herbal medicines, as well as flowers serving as dietary herbal medicines, were discussed. Moreover, applications in Traditional Chinese medicine and diet, cultivars, phytochemistry, quality control, pharmacology, and safety evaluation of Juhua, together with chrysanthemum breeding and biotechnology, were summarized in this paper. CONCLUSION: The theory of dietary herbal medicines, which are an important part of the Traditional Chinese medicine system, has a history of thousands of years. Many herbal flowers, serving as dietary herbal medicines, contribute significantly to the prevention and treatment of a variety of diseases for Chinese people. To better benefit human health, more effective supervision practice for dietary herbal medicines is needed. Although various investigations on Juhua have been done, there is a lack of analytical methods for discrimination of cultivar flowers and identification of authenticity. Research on the major compounds with bioactivities, especially those related to its clinical application or healthcare function, as well as their possible mechanize, need be strengthened. More safety evaluation of Juhua should be carried out. The research limitations Juhua is facing exist in all dietary herbal medicine.

[Effects of planting density on yield and quality of Chrysanthemum morifolium].

In this paper, five field density treatments were set up in the field plot experiment, which were 2 500,3 000,5 000,6 660,8 000 plants/mu(1 mu≈667 m~2). The agronomic traits, economic traits, mineral element absorption and the content of effective components of Chrysanthemum morifolium under different densities were studied. The results showed that dense planting could significantly reduce the number of secondary branches of Ch. morifolium and the yield per plant, but significantly increase the population yield of Ch. morifolium. The yield of Ch. morifolium was the highest when the density was 8 000 plants/mu, but the effect of increasing yield would gradually decrease with the increase of planting density. With the increase of planting density, the N, P and Mg elements in flowers firstly increased and then decreased. The N element content in leaves increased gradually, which showed that increasing the planting density within a certain range could increase the absorption of N, P and Mg elements in flowers and leaves of Ch. morifolium. The contents of rutin, chlorogenic acid and 3,5-O-dicaffeoyl quinic acid in Ch. morifolium showed a trend of first increasing and then decreasing with the increase of planting density. When the planting density was 5 500,5 000,3 750 plants/mu, the content of chlorogenic acid, rutin and 3,5-O-dicaffeyl quinic acid had the maximum value. The content of luteolin in Ch. morifolium decreased gradually with the increase of planting density. When the planting density was 7 143 plants/mu, the content of luteolin was the minimum. Considering factors such as yield and active ingredient content, the cultivation density of 5 000 plants/mu(row spacing 40 cm×30 cm) can be selected for standard planting of Ch. morifolium.

[Changes of growth and yield characters of five varieties (lines) of tea-applied chrysanthemum under different planting dates and pinching patterns]. / 不同定植期和摘心方案下5个品种(系)茶用菊生长和产量性状的变化.

To identify the high yield planting date and pinching pattern, we compared the yields of five new varieties (lines) of tea-applied chrysanthemum, the ‘Suju 10’, ‘Suju 12’, ‘Suju 13’, ‘CH1-44’ and ‘CH5-13’. A field experiment with split-split plot design was carried out. The main plot treatments including three (early, middle and late) planting dates, split-plot treatments including 5 new varieties (lines), and split-split-plot treatments including four different kinds of pinching schemes. The results showed that the yield of ‘CH5-13’ and ‘Suju 13’ was relatively higher among the five varieties (lines), followed by ‘CH1-44’ and ‘Suju10’, and ‘Suju 12’ showed the lowest yield. Among the five varieties (lines), planting date on May 27th and two-time pinching treatments showed the highest values of plant height, crown width, flower number, flower diameter, fresh mass, yield per plant and yield per unit area. Compared with the planting date on May 7th and June 13th, the above indexes increased by 16.0% and 19.0%, 18.0% and 22.8%, 36.7% and 42.2%, 11.1% and 2.3%, 13.0% and 4.0%, 47.8% and 36.6%, 48.5% and 36.7%, respectively. With the pinching time postponed, plant height decreased. Compared with the no pinching treatment, plant height of the two-time pinching treatment decreased by 50.2%, and values of crown width, flowers number, the flower fresh mass, the yield per plant and the yield per unit area were highest, with increases of 17.0%, 29.1%, 5.5%, 34.0% and 34.8%, respectively. The impact performance of three main factors on the growth and yield of the tea-applied chrysanthemum was in order of planting date>varieties>pinching time.

[Quality assessment of soil fertility of planting Chrysanthemum morifolium areas of Macheng city based on minimum data set].

A minimal data set( MDS) for soil fertility evaluation of Chrysanthemum plantation areas of Macheng city was established by principal component analysis( PCA) combined with Norm values of soil fertility indices and correlation coefficients among indices. A radar map was used to visually reflect the fertility level of individual indicators. Then,the comprehensive index model was used to calculate the soil fertility quality index( SFQI),and the values of SFQI was used to cluster,and the results showed that MDS was composed of five indicators: organic matter( OM),total phosphate( TP),available phosphorus( Av P),available magnesium( Av Mg) and available ferrum( Av Fe). Radar maps showed that the fertility of available phosphorus( Av P) and available copper( Av Cu) was mostly different in the two town,and the fertility of available ferrum( Av Fe) is smallest different. Except for the effective manganese( Av Mn) fertility level of Huangtugang town was higher than that of Futianhe town,the rest were lower than that of Futianhe town. Through analysis,the sensitivity of SFQI value calculated by taking the contribution rate of MDS index in the principal component of the whole data set( TDS) as the weight was the highest,MDS could better replace TDS. The value of SFQI-MDS ranged from 0. 353 to 0. 833,with an average value of 0. 604 and a coefficient of variation of 22%. The results of SFQI-MDS clustering showed that soil fertility could be divided into four categories: grade Ⅰ( 0. 727-0. 833) was superior,accounting for 25. 0%,grade Ⅱ( 0. 615-0. 681)was good,accounting for 29. 2%,mainly distributed in Futianhe Town,grade Ⅲ( 0. 494-0. 589) was medium,accounting for29. 1%,and grade Ⅳ( 0. 353-0. 419) was poor,accounting for 16. 7%,mainly distributed in Huangtugang town. Soil fertility of Futianhe town was better than that of Huangtugang town. It is suggested that boron fertilizer and potassium fertilizer should be supplemented to Chrysanthemum morifolium in production practice,and the amount of phosphate fertilizer,magnesium fertilizer and nitrogen fertilizer should be increased appropriately. At the same time,the amount of organic fertilizer should be increased to enhance soil fertility and improve soil physical and chemical properties.

The Chrysanthemum nankingense Genome Provides Insights into the Evolution and Diversification of Chrysanthemum Flowers and Medicinal Traits.

The Asteraceae (Compositae), a large plant family of approximately 24 000-35 000 species, accounts for ∼10% of all angiosperm species and contributes a lot to plant diversity. The most representative members of the Asteraceae are the economically important chrysanthemums (Chrysanthemum L.) that diversified through reticulate evolution. Biodiversity is typically created by multiple evolutionary mechanisms such as whole-genome duplication (WGD) or polyploidization and locally repetitive genome expansion. However, the lack of genomic data from chrysanthemum species has prevented an in-depth analysis of the evolutionary mechanisms involved in their diversification. Here, we used Oxford Nanopore long-read technology to sequence the diploid Chrysanthemum nankingense genome, which represents one of the progenitor genomes of domesticated chrysanthemums. Our analysis revealed that the evolution of the C. nankingense genome was driven by bursts of repetitive element expansion and WGD events including a recent WGD that distinguishes chrysanthemum from sunflower, which diverged from chrysanthemum approximately 38.8 million years ago. Variations of ornamental and medicinal traits in chrysanthemums are linked to the expansion of candidate gene families by duplication events including paralogous gene duplication. Collectively, our study of the assembled reference genome offers new knowledge and resources to dissect the history and pattern of evolution and diversification of chrysanthemum plants, and also to accelerate their breeding and improvement.

Transcriptome analysis of differentially expressed unigenes involved in flavonoid biosynthesis during flower development of Chrysanthemum morifolium 'Chuju'.

Chrysanthemum morifolium is an ornamentally and medicinally important plant species. Up to date, molecular and genetic investigations have largely focused on determination of flowering time in the ornamental species. However, little is known about gene regulatory networks for the biosynthesis of flavonoids in the medicinal species. In the current study, we employed the high-throughput sequencing technology to profile the genome-wide transcriptome of C. morifolium 'Chuju', a famous medicinal species in traditional Chinese medicine. A total of 63,854 unigenes with an average length of 741 bp were obtained. Bioinformatic analysis has identified a great number of structural and regulatory unigenes potentially participating in the flavonoid biosynthetic pathway. According to the comparison of digital gene expression, 8,370 (3,026 up-regulated and 5,344 down-regulated), 1,348 (717 up-regulated and 631 down-regulated) and 944 (206 up-regulated and 738 down-regulated) differentially expressed unigenes (DEUs) were detected in the early, middle and mature growth phases, respectively. Among them, many DEUs were implicated in controlling the biosynthesis and composition of flavonoids from the budding to full blooming stages during flower development. Furthermore, the expression patterns of 12 unigenes involved in flavonoid biosynthesis were generally validated by using quantitative real time PCR. These findings could shed light on the molecular basis of flavonoid biosynthesis in C. morifolium 'Chuju' and provide a genetic resource for breeding varieties with improved nutritional quality.

Effects of arbuscular mycorrhizal fungi on growth and nitrogen uptake of Chrysanthemum morifolium under salt stress.

Soil salinity is a common and serious environmental problem worldwide. Arbuscular mycorrhizal fungi (AMF) are considered as bio-ameliorators of soil salinity tolerance in plants. However, few studies have addressed the possible benefits of AMF inoculation for medicinal plants under saline conditions. In this study, we examined the effects of colonization with two AMF, Funneliformis mosseae and Diversispora versiformis, alone and in combination, on the growth and nutrient uptake of the medicinal plant Chrysanthemum morifolium (Hangbaiju) in a greenhouse salt stress experiment. After 6 weeks of a non-saline pretreatment, Hangbaiju plants with and without AMF were grown for five months under salinity levels that were achieved using 0, 50 and 200 mM NaCl. Root length, shoot and root dry weight, total dry weight, and root N concentration were higher in the mycorrhizal plants than in the non-mycorrhizal plants under conditions of moderate salinity, especially with D. versiformis colonization. As salinity increased, mycorrhizal colonization and mycorrhizal dependence decreased. The enhancement of root N uptake is probably the main mechanism underlying salt tolerance in mycorrhizal plants. These results suggest that the symbiotic associations between the fungus D. versiformis and C. morifolium plants may be useful in biotechnological practice.

Effects of enhanced UV-B radiation on the nutritional and active ingredient contents during the floral development of medicinal chrysanthemum.

The paper mainly studied the effects of enhanced UV-B radiation on the nutritional and active ingredient contents during the floral development of medicinal chrysanthemum. The experiment included two levels of UV-B radiation (0 and 400µWcm(-2)). The contents of hydrogen peroxide (H2O2), anthocyanin, UV-B absorbing compounds, total chlorophyll and carotenoids, and the activities of phenylalanine ammonia lyase enzyme (PAL) and cinnamic acid-4-hydroxylase enzyme (C4H) in flowers significantly decreased with the floral development. However, the contents of soluble sugar, amino acid and total vitamin C in flowers significantly increased with the floral development. The contents of flavonoid and chlorogenic acid were significantly different in the four stages of floral development, and their highest contents were found in the bud stage (stage 2). In the four stages of floral development, enhanced UV-B radiation significantly increased the contents of H2O2, UV-B absorbing compounds, chlorophyll, carotenoids, soluble sugar, amino acid, vitamin C, flavonoid and chlorogenic acid, and the activities of PLA and C4H in flowers. The results indicated that the highest contents of active and nutrient ingredients in flowers were found not to be in the same developmental stages of flowers. Comprehensive analysis revealed that the best harvest stage of chrysanthemum flowers was between the bud stage and the young flower stage (stage 2 and stage 3), which could simultaneously gain the higher contents of active and nutritional ingredients in flowers.

[Comparison of major bioactive components from leaves of Chrysanthemum morifolium].

Leaves of Chrysanthemum morifolium were potential medicinal resource. The present study aims to estimate the main bioactive components: total flavonoids (TF), galuteolin (GA), quercitrin (QU), chlorogenic acid (CA) and 3 ,5-O-caffeoylquinic acid ( CQ), which were considered to be the main effective components, in leaves of C. morfolium cultivars in China. The TF content was estimated hy UV-VIS spectrophotometry, while GA, QU, CA, and CQ were quantitatively determined by HPLC. The highest TF content (7. 13% w/w) was found in cultivar Wan Cong (Shexian county). Cultivar Da Bo ( Bozhou county) had the highest GA content (33. 45 mg - g-1); Cultivar Hong Xin (Sheyang county) contained the highest QU content (29.25 mg · g(-1)); Cultivar Chang Ban (Sheyang county) had the highest CA content (13.14 mg ·(-1)). The maximum CQ content (7.35 mg · g(-1)) was observed in culti- r Da Yang ( Tongxiang county). Different cultivars of C. morfolium had significant difference in components, but the leaf and capitulum of C. morifolium. were found to possess similar chemical compositions. The high content of bioactive components in several cultivars suggested the potential utilization of C. morifolium leaves.

The changes in quality ingredients of Qi chrysanthemum flowers treated with elevated UV-B radiation at different growth stages.

The paper mainly reported the changes in quality ingredients of Qi chrysanthemum flowers treated with elevated UV-B radiation at different growth stages. The experiment included two levels of UV-B radiation (ambient UV-B, a 10% increase in ambient UV-B). Elevated UV-B radiation was carried out for 10-days during seedling, vigorous growth, bud and flower stages of Qi chrysanthemum, respectively. Elevated UV-B treatments applied during four development stages did not significantly affect flower yield, the rate of superoxide radical production and malondialdehyde concentration in flowers, while increased free amino acid concentration. The amino acid concentration induced by elevated UV-B radiation applied during bud stage was higher than that during the other stages. Elevated UV-B radiation applied during vigorous growth (except for flavone), bud and flower stages of chrysanthemum significantly increased hydrogen peroxide concentration, phenylalanine ammonia lyase enzyme activity, vitamin C, chlorogenic acid and flavone concentrations in flowers. These results suggested that active and nutritional ingredients in flowers of chrysanthemum could be increased by elevated UV-B radiation applied during the later growth stages of chrysanthemum. The paper supplied a simple and environmental-friendly method to improve quality of medicinal plants.

Apple pollen as a supplemental food source for the control of western flower thrips by two predatory mites, Amblyseius swirskii and Neoseiulus cucumeris (Acari: Phytoseiidae), on potted chrysanthemum.

It has been shown that pollen as a dietary supplement may increase the establishment (development and reproduction) and survival of phytoseiid predatory mites, and therefore the pest control these mites can provide. In this study, the role of apple pollen as a supplemental food source was assessed as a means to increase the efficiency of two predatory mite species, Neoseiulus cucumeris and Amblyseius swirskii, for control of western flower thrips, Frankliniella occidentalis, under greenhouse conditions. The impact of apple pollen on thrips populations and predator establishment on a greenhouse chrysanthemum crop was determined over a 4-week period. The two mite species were released separately and in combination with and without pollen with two control treatments (thrips only and thrips + pollen). The introduction of A. swirskii together with pollen application provided the best control of thrips (adults and immatures). The establishment of N. cucumeris was very low in the crop during the greenhouse trial. This could be attributable, in part, to their response to extreme temperature ranges that were encountered during the greenhouse cage trials. The use of A. swirskii alone and the mixed population of the two predatory mite species without pollen resulted in the lowest frequencies of plants with heavy damage, followed by the same treatments with the addition of apple pollen.

[Effect of Crop Rotation and Biological Manure on Quality and Yield of "Chuju" Chrysanthemum morifolium and Continuous Cropping Soil Enzyme Activities].

OBJECTIVE: To investigate the effects of chrysanthemum-wheat rotation system and biological manure on continuous cropping soil enzyme activities and quality and yield of Chrysanthemum morifolium. METHODS: Field experiments were conducted at the research base of Anhui Jutai Chuju Chrysanthemum morifolium Herbal Technology Co. , Ltd. ,in Shiji Town, Nanqiao Country, Anhui Province. Samples were collected from treatments under chrysanthemum-wheat rotation system receiving bio-organic manure application of 200 kg/667 m2, conventional chrysanthemum-wheat rotation system and chrysanthemum continuous cropping system. RESULTS: Chrysanthemum-wheat rotation system and biological manure obviously influenced the quality and yield of Chrysanthemum morifolium and continuous cropping soil enzyme activities. Compared with chrysanthemum continuous cropping system, total flavonoids, chlorogenic acid, soluble sugar and free amino acid contents, quantitative of ray floret, inflorescence diameter, diameter of tubular floret, number of branch, number of flower and yield of Chrysanthemum morifolium and the activities of urease, acid phosphatase, invertase and protease in soil were increased to 42.59 mg/g, 2.52 mg/g, 4.04 mg/g, 73.33 mg/100 g, 179.56, 5.57 cm, 1.43 cm, 36.10, 330.00 and 400.09 kg/667 m2, respectively, while hydrogen peroxidase of soil under chrysanthemum-wheat rotation system was decreased. CONCLUSION: Bio-organic manure application of 200 kg/667 m2 is benefit to soil environment establishment of chrysanthemum-wheat rotation system and enhancement of quality and yield of Chrysanthemum morifolium while reducing the obstacles of continuous cropping.

[Study on combined effects of chemical components for different flowers blossoming degree of yellow medicinal Chrysanthemum morifolium from Zhejiang].

The ingredients of five kinds of Zhejiang's yellow Chrysanthemum morifolium with different flower blossoming stages were comparatively analyzed. Polysaccharides, total flavonoids, volatile oil, alcohol extract, water extract, chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid and fingerprint of the ingredient were determined as indicators. During flower blossoming stages, the ingredients of Ch. morifolium showed a big difference with a certain variation. At the early opening stage, the contents of flavonoids and volatile oil were higher, the content of chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid were higher in the middle of the flowers 50% -80% fowers blossoming degree is the optimal time for harvest.

Phosphate enhances uptake of As species in garland chrysanthemum (C. coronarium) applied with chicken manure bearing roxarsone and its metabolites.

Roxarsone (ROX), a world widely used feed organoarsenic additive in animal production, can be excreted as itself and its metabolites in animal manure. Animal manure is commonly land applied with phosphorous (P) fertilizer to enhance the P phytoavailability in agriculture. We investigated the accumulation of As species in garland chrysanthemum (C. coronarium) plants fertilized with 1% (w/w, manure/soil) chicken manure bearing ROX and its metabolites, plus 0, 0.05, 0.1, 0.2, 0.4, and 0.8 g P2O5/kg, respectively. The results show that As(III) was the sole As compound in garland chrysanthemum shoots, and As(III) and As(V) were detectable in roots. Elevated phosphate level supplied more As(V) for garland chrysanthemum roots through competitive desorption in rhizosphere, leading to significantly enhanced accumulation of As species in plants. As(III) was the predominant As form in plants (85.0∼90.6%). Phosphate could not change the allocation of As species in plants. Hence, the traditional practice that animal manure is applied with P fertilizer may inadvertently increase the potential risk of As contamination in crop via the way ROX → animal → animal manure → soil → crop.

[Effects of nitrogen form on growth and quality of Chrysanthemums morifolium].

This paper is aimed to study the effects of nitrogen form on the growth and quality of Chrysanthemums morifolium at the same nitrogen level. In order to provide references for nutrition regulation of Ch. morifolium in field production, pot experiments were carried out in the greenhouse at experimental station of Nanjing Agricultural University. Five proportions of ammonium and nitrate nitrogen were set up and a randomized block design was applied four times repeatedly. The results showed that the growth and quality of Ch. morifolium were significantly influenced by the nitrogen form. The content of chlorophyll and photosynthesis rate were the highest at the NH4(+) -N /NO3(-) -N ratio of 25:75; The activities of NR in different parts of Ch. -morifolium reached the highest at the NH4(+) - N/NO3(-) -N ratio of 0: 100. The contents of nitrate nitrogen in the root and leaves reached the highest at the NH4(+) -N/NO3(-) -N ratio of 50:50. The activities of GS, GOGAT and the content of amylum increased with the ratio of NO3(-) -N decreasing and reached it's maximum at the NH4 + -N/NO3 - -N ratio of 100: 0. The content of ammonium nitrogen were the highest at the NH4 + -N /NO3 --N ratio of 75: 25, while the content of soluble sugar reached the highest at the NH4(+)-N/NO3(-) -N ratio of 25: 75. The content of flavones, chlorogenic acid and 3,5-O-dicoffeoylqunic acid were 57.2 mg x g(-1), 0.673% and 1.838% respectively, reaching the maximum at the NH4(+) -N /NO3(-) -N ratio of 25:75; The content of luteoloside increased with the ratio of NO3(-) -N increasing and reached it's maximum at the NH4(+) -N/NO3(-) -N ratio of 0: 100. The yield of Ch. morifolium reached it's maximum at the NH4(+) -N /NO3(-) -N ratio of 25:75. Nitrogen form has some remarkable influence on the nitrogen metabolism, photosynthesis and growth, Nitrogen form conducive to the growth and quality of Ch. morifolium at the NH4(+) -N /NO3(-) -N ratio of 25: 75.

[Effect of different treatment on endophytic bacterial communities in continuous cropping of Chrysanthemum morifoliu].

To reveal the effect of rotation cropping and bacterial manure on the growth of Chrysanthemum morifolium and screen the beneficial endophytic, the diversity of endophytic and dominant genera of different treatment groups were analyzed. Four different treatments were continuous cropping, rotation, self-made organic fertilizer and commercially available fertilizer, respectively. Endophytic bacterial diversity and dominant genera in different organs were examined using Terminal Restriction Fragment Length Polymorphism (T-RFLP). The results showed that enzyme Hae III was more appropriate than enzyme Hinfl because the number of TRFs digested by enzyme Hae III was more than that of enzyme Hinfl. In comparison of diversity, the endophytic bacterial communities' diversity index in group of cropping rotation and fertilizer was higher than that of continuous cropping which indicated that the addition of exogenous microorganism in soil could increase the diversity of plant endophyte. 18 dominant species were selected, including 3 kinds of Firmicutes, 4 kinds of Actinomycetes and 11 kinds of Proteobacteria. The results of dominant species comparison showed that the number of dominant species in continuous cropping of Ch. morifolium was significantly less than that of the rotation group. Some dominant bacteria in rotation group and fertilizer group such as Arthrobacter, Streptomyces, Streptomyces, Flavobacterium and Mycobacterium were not found in the continuous cropping of Ch. mortfolium group. Dominant species of fertilizer treatment group was similar with the rotation group, and the continuous cropping group's dominant species was more abundant. It indicates that these bacteria may be able to mitigate hindrance in continuous cropping, especially the Flavobacterium which can decompose the pathogenic fungi is worthy of further attention. Compared with leaves, there are more dominant species in roots and stems. The diversity of edophytic bacterial communities in continuous cropping of Ch. morifolium stays below than that in the rotation of Ch. morifolium, and fertilizer treatment can increase the diversity of continuous cropping so that it could mitigate hindrance in continuous cropping.

[Analysis of trace elements in chrysanthemum from different habitats with ICP-MS].

OBJECTIVE: To establish a method for determination of trace elements in chrysanthemum and analyze trace elements in chrysanthemum from different habitats. METHODS: The preprocessing for determination of trace elements in chrysanthemum was carried out by microwave digestion,the content of trace elements in chrysanthemum was determined by ICP-MS. RESULTS: The content of trace elements of chryscmthemum varied with the habitats. CONCLUSION: The contents of trace elements as well as heavy metals of Chrysanthemum relate to its species and habitats to a certain degree.

Expression profile analysis of genes involved in horizontal gravitropism bending growth in the creeping shoots of ground-cover chrysanthemum by suppression subtractive hybridization.

The molecular mechanisms underlying gravitropic bending of shoots are poorly understood and how genes related with this growing progress is still unclear. To identify genes related to asymmetric growth in the creeping shoots of chrysanthemum, suppression subtractive hybridization was used to visualize differential gene expression in the upper and lower halves of creeping shoots of ground-cover chrysanthemum under gravistimulation. Sequencing of 43 selected clones produced 41 unigenes (40 singletons and 1 unigenes), which were classifiable into 9 functional categories. A notable frequency of genes involve in cell wall biosynthesis up-regulated during gravistimulation in the upper side or lower side were found, such as beta tubulin (TUB), subtilisin-like protease (SBT), Glutathione S-transferase (GST), and expensing-like protein (EXP), lipid transfer proteins (LTPs), glycine-rich protein (GRP) and membrane proteins. Our findings also highlighted the function of some metal transporter during asymmetric growth, including the boron transporter (BT) and ZIP transporter (ZT), which were thought primarily for maintaining the integrity of cell walls and played important roles in cellulose biosynthesis. CmTUB (beta tubulin) was cloned, and the expression profile and phylogeny was examined, because the cytoskeleton of plant cells involved in the plant gravitropic bending growth is well known.