Factors affecting quantity of pollen dispersal of spray cut chrysanthemum (Chrysanthemum morifolium)
© Wang et al.; licensee BioMed Central Ltd. 2014
Received: 27 May 2013
Accepted: 2 January 2014
Published: 6 January 2014
Spray cut chrysanthemum is a vital flower with high ornamental value and popularity in the world. However, the excessive quantity of pollen dispersal of most spray cut chrysanthemum is an adverse factor during its flowering stage, and can significantly reduce its ornamental value and quickly shorten its vase life. More seriously, excessive pollen grains in the air are usually harmful to people, especially for those with pollen allergies. Therefore, in order to obtain some valuable information for developing spray cut chrysanthemum with less-dispersed or non-dispersed pollen in the future breeding programs, we here investigated the factors affecting quantity of pollen dispersal of spray cut chrysanthemum with four cultivars, i.e. ‘Qx-097’, ‘Noa’, ‘Qx-115’, and ‘Kingfisher’, that have different quantity of pollen dispersal.
‘Qx-097’ with high quantity of pollen dispersal has 819 pollen grains per anther, 196.4 disk florets per inflorescence and over 800,000 pollen grains per inflorescence. The corresponding data for ‘Noa’ with low quantity of pollen dispersal are 406, 175.4 and over 350,000, respectively; and 219, 144.2 and nearly 160,000 for ‘Qx-115’ without pollen dispersal, respectively. ‘Kingfisher’ without pollen dispersal has 202.8 disk florets per inflorescence, but its anther has no pollen grains. In addition, ‘Qx-097’ has a very high degree of anther cracking that nearly causes a complete dispersal of pollen grains from its anthers. ‘Noa’ has a moderate degree of anther cracking, and pollen grains in its anthers are not completely dispersed. However, the anthers of ‘Qx-115’ and ‘Kingfisher’ do not crack at all. Furthermore, microsporogenesis and pollen development are normal in ‘Qx-097’, whereas many microspores or pollen degenerate in ‘Noa’, most of them abort in ‘Qx-115’, and all of them degrade in ‘Kingfisher’.
These results suggest that quantity of pollen dispersal in spray cut chrysanthemum are mainly determined by pollen quantity per anther, and capacity of pollen dispersal. Abnormality during microsporogenesis and pollen development significantly affects pollen quantity per anther. Capacity of pollen dispersal is closely related to the degree of anther dehiscence. The entire degeneration of microspore or pollen, or the complete failure of anther dehiscence can cause the complete failure of pollen dispersal.
Chrysanthemum (Chrysanthemum morifolium (Ramat.) Kitamura) is among the ten most popular traditional flowers in China and one of the four most popular cut flowers in the world. Thus, this species occupies a vital position in production of flowers due to its high ornamental value [1, 2]. Spray cut chrysanthemum is a type of chrysanthemum important in chrysanthemum production. It has become the most important cut flower in China, and the second largest type of cut flowers in the United States and Europe, due to richness in floral colors and shapes, uniform flowering, and plentiful spray flowers as well [3, 4]. However, the ornamental value and vase life of spray cut chrysanthemum usually drop with the increase in quantity of pollen dispersal of middle tubular bisexual flowers at the flowering stage. More seriously, plenty of pollen grains produced by spray cut chrysanthemum at the flowering stage will float in the air and may cause severe allergic reactions that could be harmful to people, in particular those with pollen allergies [5–7]. Therefore, it is very necessary and urgent to solve the problem of pollen contamination during flowering of spray cut chrysanthemum.
It will be very useful to have some important information on factors influencing quantity of pollen dispersal of spray cut chrysanthemum before starting to develop new cultivars that disperse less pollen or do not disperse pollen at all through breeding methods. However, such information is not available by now. Therefore, we are the first time to carry out a systematic investigation on factors controlling quantity of pollen dispersal of spray cut chrysanthemum in this study using four cultivars with different quantity of pollen dispersal, i.e. ‘Qx-097’ with high quantity of pollen dispersal, ‘Noa’ with low quantity of pollen dispersal, ‘Qx-115’ and ‘Kingfisher’ without pollen dispersal. Our overall aim was to reveal the main causes influencing quantity of pollen dispersal of spray cut chrysanthemum, and the expected outputs will provide valuable information for effectively developing new cultivars with less-dispersed or non-dispersed pollen in the near future.
According to our previous observations on morphological characteristics of pollen dispersal, four spray cut chrysanthemum cultivars with different quantity of pollen dispersal were screened and grown in the Chrysanthemum Germplasm Resource Preserving Center, Nanjing Agricultural University, China (32°05’ N, 118°90’ E). They were ‘Qx-097’ with high quantity of pollen dispersal, ‘Noa’ with low quantity of pollen dispersal, ‘Qx-115’ and ‘Kingfisher’ without pollen dispersal, respectively (Figure 1).
Determination on pollen quantity per inflorescence
Because each chrysanthemum inflorescence usually consists of 20-30 peripheral ray florets which contain only a pistil and 100-200 small central disk florets with both pistil and stamen, thus only central disk florets can produce pollen and disperse pollen . Therefore, ten inflorescences at the full flowering stage of each cultivar were randomly sampled for determining the number of central disk florets per inflorescence. In addition, ten central disk florets were randomly selected for determining the number of anther per disk floret. Furthermore, 60 anthers just before dehiscence were randomly sampled from each cultivar for estimating the number of pollen per anther. The anthers were put in a 10 ml centrifuge tube, and then stored at 50°C for around 24 hours. Afterwards, 6 ml of 20% (NaPO3)6 solution (w/v) was added into the centrifuge tube, and then the tube was shaken and inverted completely to produce pollen suspension. 2 μl of pollen suspension was added on a hemocytometer and pollen amount was counted under an Olympus BX41 microscope. Pollen quantity per anther was calculated with the formula [pollen quantity per anther (pollen grains/anther) = the number of pollen grains in 2 μl suspension × 3000/60]. Each experiment was repeated six times. Pollen quantity per inflorescence was calculated according to pollen quantity per anther, number of anthers per disk floret, and number of disk florets per inflorescence, i.e. pollen quantity per inflorescence = pollen quantity per anther × number of anthers per disk floret × number of disk florets per inflorescence.
Determination on pollen dispersal
At the full flowering stage of each cultivar, the images of pollen on stigmas were captured for the purpose of assessing morphological characteristics of pollen dispersal. In addition, the anthers after their pollen dispersal were collected for determining the level of anther cracking and the amount of pollen left per anther by the above-mentioned method. Furthermore, some of the anthers after their pollen dispersal were subject to the following microscopy technology.
Microsporogenesis and pollen development
Microsporogenesis and pollen development of the four cultivars were examined according to the paraffin section method of [11, 12] with some modifications. Flower buds and disk florets of each cultivar at different development stages were collected, and immediately immersed in FAA solution (formalin 5 ml, acetic acid 5 ml, alcohol 70% 90 ml) until use. The samples were dehydrated through a graded series of ethanol solutions, and then embedded in paraffin wax. Sections were cut to a thickness of 8 μm and stained with Heidenhain’s hematoxylin. Then the sections were observed and imaged under an Olympus BX41 microscope. Digital images were captured using an Axiocam MRC camera.
In addition, the anthers of ‘Qx-097’ and ‘Noa’ at different development stages were also subject to transmission electron microscopy (TEM) by [13, 14] with some modifications. Fresh anthers were stripped from central disk florets and immediately immersed in 2.5% (v/v) glutaraldehyde (in 0.1 mol/L phosphate buffer, pH 7.2), gently expelled using a syringe, and then stored at 4°C until use. Then the anthers were washed five times with the same phosphate buffer and post-fixed in 1.5% osmium tetroxide for 5 h. Afterwards, they were treated through a graded series of PHEM buffer (60 mmol/L pipes; 25 mmol/L Hepes; 10 mmol/L EGTA; 2 mmol/L MgCl2; pH 7. 0) and ethanol solutions, and then embedded in Epon 812. Sections were cut to a thickness of 80 nm using an LKB-V ultra-microtome (Bromma, Sweden) and stained with uranyl acetate and lead citrate. The sections then were observed and imaged under a transmission electron microscope (Hitachi H-7650) at 80 kV.
The data were subjected to a one-way analysis of variance using the SPSS software 16.0 (SPSS Inc, Chicago, IL, USA), and the means were compared using the Bonferroni t-test with alpha = 0.05.
Pollen quantity per inflorescence
Inflorescence traits of four spray cut chrysanthemum cultivars
Disk florets per inflorescence
Anthers per floret
Pollen quantity per anther
Pollen quantity per inflorescence
Apparent pollen quantity
Anther dehiscence degree
Percentage of pollen dispersal (%)
196.4 ± 9.0ab
819 ± 30a
175.4 ± 2.9b
406 ± 31b
144.2 ± 7.0c
219 ± 19c
202.8 ± 9.3a
No pollen in anther
Pollen dispersal per inflorescence
The apparent pollen quantity is a morphological parameter that grossly indicates the amount of pollen grains gathering on stigmas during anther dehiscence of spray cut chrysanthemum. In other words, this parameter is an intuitive reflection of quantity of pollen dispersal, or can be regarded as a criterion assessing the capacity of chrysanthemum pollen dispersal. For example, mass of pollen grains on stigmas of ‘Qx-097’ during anther dehiscence were clearly visible and large in volume (Figure 1A-D), so ‘Qx-097’ is a cultivar with high quantity of pollen dispersal. There are also mass of pollen grains on stigmas of ‘Noa’ during anther dehiscence, but pollen mass is much smaller in volume compared with that of ‘Qx-097’ (Figure 1E-H). Thus, ‘Noa’ is considered as a chrysanthemum cultivar with low quantity of pollen dispersal. ‘Qx-115’ does not disperse pollen during anther dehiscence and no any pollen grains can be observed on its stigmas (Figure 1I-L). Therefore, ‘Qx-115’ is regarded as a cultivar without pollen dispersal, although it has 219 pollen per anther and nearly 160,000 per inflorescence (Table 1). ‘Kingfisher’ does not dispersal pollen at all during anther dehiscence (Figure 1M-P), as its anther or inflorescence does not contain any pollen (Table 1), thus it is a cultivar with non-dispersed pollen.
Microsporogenesis and pollen development of ‘Qx-097’
Because ‘Qx-097’ is a cultivar with high quantity of pollen dispersal, thus the detailed reproductive processes of microsporogenesis and pollen development were presented here, which will provide some useful information for revealing the reason of its high quantity of pollen dispersal from reproductive aspect.
Microsporogenesis and pollen development of ‘Noa’, ‘Qx-115’ and ‘Kingfisher’
Comparisons of microsporogenesis, pollen development and pollen dispersal among four spray cut chrysanthemum cultivars
Major events in pollen development and pollen dispersal of ‘Qx-097’
The differences of ‘Noa’, ‘Qx-115’ and ‘Kingfisher’ compared with ‘Qx-097’
Microsporocyte formation stage
Tissue differentiation, microspore mother cells in irregular shape, tightly abutting, relatively large nuclei, formation of 4 complete anther walls.
Microsporocyte meiosis stage
Oval-shaped microspore mother cells, meiosis, microspores in tetrahedral tetrads, microspore mother cells and tetrads surrounded by callose and abundant cytoplasm contains mitochondria, plastids, endoplasmic reticulum, small vacuoles, vacuolation of cytoplasm of endothecium layer and epidermal layer cells, condensed cytoplasm of tapetal layer cells.
‘Kingfisher: asymmetrical dyad and tetrad formed by inequality meiosis, degradation and vacuolization of microspore cytoplasm in tetrad, abnormal degradation and microspores not released from tetrads.
Early microspore stage
Free microspores released from tetrads, no vacuoles, no germ pores, thin cell wall, uniform and dense cytoplasm, nuclei in center of cells. vacuolation of cytoplasm of tapetal layer with discohesive cells increase, middle layer in further degradation;
‘Kingfisher’: nothing in pollen sacs, pollen abortion completely;
‘Noa’: individual microspore abortion.
Middle microspore stage
Microspore enlargement, germ pores formation, cells wall thickenings formed, spiked protuberances formed and inner wall formed, vacuoles increase and enlargement, degradation of microspore cytoplasm, off-centre of nuclei, tapetal layer cells radial thinning.
‘Qx-115’: large number of microspore abortion, cells broken, degradation of cytoplasm;
‘Noa’: individual microspore abortion;
‘Kingfisher’: nothing in pollen sacs.
Late microspore stage
Cell walls thickened and cells enlargement continues, large central vacuole formation, nuclei and cytoplasm at opposite side of germ pores against outer walls, tapetal layer cells in hill-shaped and further degradation, middle layer almost disappeared.
‘Qx-115’: microspore abortion continues, few complete pollen grains in the late microspore stage;
‘Noa’: individual microspore abortion;
‘Kingfisher’: nothing in pollen sacs.
Early bicellular pollen stage
Inequality mitosis of microspore, vegetative cell and generative cell formation, remains of tapetal layer, endothecium layer cells enlargement.
Anthers start shriveling of ‘Qx-115’ and ‘Kingfisher’.
Late bicellular pollen stage
Bicellular pollen stage enlargement, move of generative cell to vegetative cell, starch accumulation, ‘U’ shaped thickened of endothecium layer cell walls.
Anthers shriveled of ‘Qx-115’ and ‘Kingfisher’.
Mature pollen stage
The contents like starch fill the whole cytoplasm, generative cell dividing, sperm cells and mature pollen formation, non observation of 3-nuclei structure.
Anthers shriveled of ‘Qx-115’ and ‘Kingfisher’.
Anther cracking and pollen dispersing stage
Anther cracking, pollen dispersing, very high degree of anther cracking, pollen dispersing completely.
‘Noa’: the degree of anther cracking inferior to ‘Qx-097’, pollen residue remains after pollen dispersing;
‘Qx-115’: anther non-cracking, non-dispersal of pollen.
Stamen anatomy during anther dehiscence of ‘Qx-097’, ‘Noa’, and ‘Qx-115’
Pollen is produced by plant stamen, the male reproductive organ of flower, and is very important for sexual reproduction of flowering plants [15, 16]. However, pollen is often unwelcome in flower production, as the ornamental value of many flowers including chrysanthemum usually quickly decrease with the increase in quantity of pollen dispersal [17, 18]. In addition, pollen can also create various allergic reactions in people [5, 6, 19, 20]. In this study, four spray cut chrysanthemum cultivars are very different in the quantities of pollen dispersal. ‘Qx-115’ and ‘Kingfisher’ are cultivars with non-dispersing of pollen, ‘Qx-097’ is the cultivar with high quantities of pollen dispersal, and ‘Noa’ is the cultivar with less quantities of pollen dispersal (Figure 1, Table 1). The results presented here indicate that the significant differences in the quantities of pollen dispersal among the four chrysanthemum cultivars are largely due to two factors, pollen quantity per inflorescence and the capacity of pollen dispersal. In other words, the quantity of pollen dispersal is usually positively proportional to pollen quantity per inflorescence and the capacity of pollen dispersal.
Pollen quantity per inflorescence of spray cut chrysanthemum is jointly determined by pollen quantity per anther and the number of disk florets per inflorescence, but pollen quantity per anther is the main factor. Because the number of disk florets per inflorescence usually ranges from 100 to 200, whereas pollen quantity per anther has a wider range, usually 0-1000 (Table 1). There are many factors affecting pollen quantity per anther. For example, pollen quantity in the anther is influenced by the size of pollen sacs, the number of microspores mother cells, climate and nutrient conditions, and level of cultivation and management [15, 21, 22]. Liu et al.  and Tan et al.  thought that pollen quantity in anthers also depends on whether anthers develop normally. In the present study, we compared microsporogenesis and pollen development of the four cultivars with different quantities of pollen dispersal, and found that abnormalities often occurred during microsporogenesis and pollen development of ‘Kingfisher’, ‘Qx-115’, and ‘Noa’. For instance, nearly all the microspores mother cells degraded at the microsporocyte meiosis stage and asymmetrical dyad and tetrad in ‘Kingfisher’, which is the main reason why anther of this cultivar does not contain any pollen. However, abnormal phenomena were seldom observed in ‘Qx-097’ with lots of pollen grains in anther. Therefore, the reason for difference in pollen quantity per anther of the four chrysanthemum cultivars is mainly attributed to different levels of abnormalities occurring during microsporogenesis and pollen development. The possible reason for different levels of abnormalities is that long-term vegetative propagation of chrysanthemum, mainly cutting, has resulted in chromosome structure variation and abnormal meiosis. Similar phenomena were also observed in lily [25, 26].
The capacity of pollen dispersal is another important factor influencing quantity of pollen dispersal in chrysanthemum, and is closely related to the speed and degree of anther dehiscence. The speed of anther dehiscence is the degree of anther dehiscence per unit time. We hypothesized that the higher the degree of anther dehiscence is, the stronger its capacity of pollen dispersal is. This hypothesis is confirmed by our results (Table 1). For example, ‘Qx-097’ has the highest degree of anther dehiscence among the four cultivars, and its pollen grains in anther disperse completely. ‘Qx-115’ does not disperse any pollen because its anthers do not crack at all, although its anther contains lots of pollen. The reason for anther abnormal cracking in ‘Qx-115’ may be the anther atrophy caused by pollen abortion and the anther walls of this cultivar has no special structure suitable for anther dehiscence. For ‘Qx-097’ and ‘Noa’, the cell walls in endothecium layer are ‘U’ shaped and thickened that may facilitate anther dehiscence, although the difference in degree of anther dehiscence between the two cultivars remains to be further investigated.
Anther dehiscence was once considered a simple process of tissue desiccation [27, 28]. However, many studies showed that anther dehiscence is a complex process which is regulated by different mechanisms in different species [29–33]. For example, water channel protein, carbohydrate and K+ have been reported to be implicated in anther dehiscence by regulating cell osmatic potential which gave rise to dehydration of the tissue of anthers [34–36]. In addition, anther dehiscence was also regulated by hormones including jasmonic acid [37, 38], auxin  and ethylene [39, 40]. The main regulation model is that when anther tissue is under the regulation of hormones such as jasmonic acid etc., pollen grains and septum dehydrate at the right moment, and then K+ and secondary metabolites such as carbohydrate enter pollen grains and cause their rapid swell to produce the pressure on stomium under the help of water channel protein. Meanwhile, hormones such as ethylene promote the rupture of stomium cells by enzymatic hydrolysis to crack the anthers at last [29, 31, 33, 41]. For instance, Sanders et al. and Nagpal et al. found that anthers of Arabidopsis mutant with defection in anther dehiscence could open after treatment with exogenous jasmonic acid and auxin. However, our results (data not shown) indicated that exogenous methyl jasmonate treatment couldn’t accelerate anther dehiscence of ‘Noa’ with incomplete dehiscent anthers and ‘Qx-115’ with non-dehiscent anthers, demonstrating jasmonic acid is possibly not a main factor affecting anther cracking in chrysanthemum. Moreover, external environment factors such as high temperature sometimes can also decrease the degree of anther dehiscence [44, 45].
In conclusion, we here performed a systematic study to investigate factors influencing quantity of pollen dispersal of four spray cut chrysanthemum cultivars with different quantity of pollen dispersal. Three findings are worth noting. Firstly, quantity of pollen dispersal in spray cut chrysanthemum are largely determined by pollen quantity per anther, and capacity of pollen dispersal. Secondly, significant differences in pollen quantity per anther among the four chrysanthemum cultivars are mainly attributable to significant differences in abnormalities occurring during microsporogenesis and pollen development. Thirdly, capacity of pollen dispersal is closely related to the degree of anther dehiscence. These important findings will provide valuable information for developing flower cultivars with less or no pollen dispersal in future breeding projects of chrysanthemum, even other crops, although the underlying mechanisms for pollen abortion and abnormal cracking of anthers remain to be further investigated.
We are very grateful to the two anonymous reviewers assigned by the BMC Plant Biology journal for carefully reviewing our manuscript and putting forward many valuable suggestions and comments. We also thank Professor Xi-Jin Mu in Institute of Botany, Chinese Academy of Sciences for his valuable discussions at early stages of these experiments. This study was supported by the Programs for New Century Excellent Talents in Universities, Ministry of Education of China (NCET-11-0669), the National Natural Science Foundation of China (31171983), the Fundamental Research Funds for the Central Universities (KYZ201308, KYZ201147), the Natural Science Foundation of Jiangsu Province (BK2010447), and Youth Science and Technology Innovation Fund (KJ2011009).
- Li HJ: Chrysanthemums in China. Nanjing: Jiangsu Scientific and TechnicalPress; 1993.Google Scholar
- Anderson NO: Chrysanthemum (Dendranthema × Grandiflora Tzvelv). Flower Breeding and Genetics. Edited by: Anderson NO. Netherlands: Springer; 2007:389-437.Google Scholar
- Chen L: Research and analysis of the international market of chrysanthemum. Greenhouse Hortic. 2005, 8: 20-22.Google Scholar
- Li YF, Fang WM, Chen FD, Chen SM, Shi CL: Effect of different planting date on phenophase and quality of spray cut chrysanthemum produced in summer. Journal of Yangzhou University (Agricultural and Life Science Edition). 2009, 30 (3): 80-83.Google Scholar
- Groenewoud GC, de Jong NW, Burdorf A, de Groot H, van Wÿk RG: Prevalence of occupational allergy to Chrysanthemum pollen in greenhouses in the Netherlands. Allergy. 2002, 57 (9): 835-840. 10.1034/j.1398-9995.2002.23725.x.View ArticlePubMedGoogle Scholar
- Lee YW, Choi SY, Lee EK, Sohn JH, Park JW, Hong CS: Cross-allergenicity of pollens from the compositae family: Artemisia vulgaris, Dendranthema grandiflorum and Taraxacum officinale. Ann Allergy Asthma Immunol. 2007, 99 (6): 526-533. 10.1016/S1081-1206(10)60382-1.View ArticlePubMedGoogle Scholar
- Yang YQ, Guo ZL: The positive and negative effects of household flowers to indoor air pollution. Environ Sci Manage. 2009, 34 (5): 31-33. 42Google Scholar
- Chan RYC, Oppenheimer JJ: Occupational allergy caused by Peruvian lily (Alstroemeria). Ann Allergy Asthma Immunol. 2002, 88 (6): 638-639. 10.1016/S1081-1206(10)61897-2.View ArticlePubMedGoogle Scholar
- Hoidn C, Puchner E, Pertl H, Holztrattner E, Obermeyer G: Nondiffusional release of allergens from pollen grains of Artemisia vulgaris and Lilium longiflorum depends mainly on the type of the allergen. Int Arch Allergy Immunol. 2005, 137: 27-36.View ArticlePubMedGoogle Scholar
- Li XX, Yi MF: Research Progress of Male Sterility in Lily. Xining: Chinese Annual Review of Flower Bulbs; 2010.Google Scholar
- Sun CQ, Huang ZZ, Wang YL, Chen FD, Teng NJ, Fang WM, Liu ZL: Overcoming pre-fertilization barriers in the wide cross of chrysanthemum by using special pollination techniques. Euphytica. 2011, 178: 195-202. 10.1007/s10681-010-0297-6.View ArticleGoogle Scholar
- Teng NJ, Wang YL, Sun CQ, Fang WM, Chen FD: Factors influencing fecundity in experimental crosses of water lotus (Nelumbo nucifera Gaertn.) cultivars. BMC Plant Biol. 2012, 12: 82-10.1186/1471-2229-12-82.PubMed CentralView ArticlePubMedGoogle Scholar
- Teng NJ, Wang J, Chen T, Wu XQ, Wang YH, Lin JX: Elevated CO2 induces physiological, biochemical and structural changes in leaves of Arabidopsis thaliana. New Phytol. 2006, 172: 92-103. 10.1111/j.1469-8137.2006.01818.x.View ArticlePubMedGoogle Scholar
- Jin B, Wang L, Wang J, Jiang KZ, Wang Y, Jiang XX, Ni CY, Wang YL, Teng NJ: The effect of experimental warming on leaf functional traits, leaf structure and leaf biochemistry in Arabidopsis thaliana. BMC Plant Biol. 2011, 11: 35-10.1186/1471-2229-11-35.PubMed CentralView ArticlePubMedGoogle Scholar
- Hu SY: Reproductive Biology of Angiosperms. Beijing: High Education Press;2005.Google Scholar
- Franklin-Tong VE: Self-Incompatibility in Flowering Plants - Evolution, Diversity, and Mechanisms. Berlin Heidelberg: Springer-Verlag; 2008.View ArticleGoogle Scholar
- Chen JY: Classification System for Chinese Flower Cultivars. Beijing: ChinaForestry Press; 2001:218–231.Google Scholar
- Jin B, Wang L, Wang J, Teng NJ, He XD, Mu XJ, Wang YL: The structure and roles of sterile flowers in Viburnum macrocephalum f. keteleeri (Adoxaceae). Plant Biol. 2010, 12: 853-862. 10.1111/j.1438-8677.2009.00298.x.View ArticlePubMedGoogle Scholar
- Ziello C, Sparks TH, Estrella N, Belmonte J, Bergmann KC, Bucher E, Brighetti MA, Damialis A, Detandt M, Galán C, Gehrig R, Grewling L, Gutiérrez Bustillo AM, Hallsdóttir M, Kockhans-Bieda MC, Linares CD, Myszkowska D, Pàldy A, Sánchez A, Smith M, Thibaudon M, Travaglini A, Uruska A, Valencia-Barrera RM, Vokou D, Wachter R, Menzel A: Changes to airborne pollen counts across Europe. PLoS ONE. 2012, 7 (4): e34076-10.1371/journal.pone.0034076.PubMed CentralView ArticlePubMedGoogle Scholar
- de Jong NW, Vermeulen AM, Gerth van Wijk R, De Groot H: Occupational allergy caused by flowers. Allergy. 1998, 53 (2): 204-209. 10.1111/j.1398-9995.1998.tb03872.x.View ArticlePubMedGoogle Scholar
- Meng JL: Plant Reproductive Genetics. Beijing: Science Publishing House;1997.Google Scholar
- Ren GB, Fang WM, Jia SZ, Chen FD: Investigation on pollen grain quantity and pollen in vitro germination characteristics in Prunus mume. Acta Agriculturae Shanghai. 2007, 23: 42-46.Google Scholar
- Liu ZH, He TM, Zhong F: Determine and analysis on the quantity of pear’s pollen. J Gansu Forestry Sci Technol. 2003, 28: 34-35. 54.Google Scholar
- Tan JM, Cen XF, Wei PX, Ma XJ, Mo CM: Study on the pollen amount and germinating capacity of different hybrid lines of Siraitia grosvenorii. Guihaia. 2009, 29: 881-884.Google Scholar
- Li X, Chen LM, Du J, Liang WF, Xing HT: Observations on abnormal meiosis of pollen mother cells in Lilium davidii var. unicolor. Acta Botanica Boreali-Occidentalia Sinica. 2003, 23: 1796-1799.Google Scholar
- Zhang CX, Ming J, Liu C, Li BS: Analysis and observation on abnormal phenomena of the meiotic behavior of pollen mother cell in the Oriental Hybrids Lily Siberia. Bull Biol. 2010, 45: 45-48.Google Scholar
- Keijzer CJ: The processes of anther dehiscence and pollen dispersal. I. The opening mechanism of longitudinally dehiscing anthers. New Phytol. 1987, 105: 487-498. 10.1111/j.1469-8137.1987.tb00886.x.View ArticleGoogle Scholar
- Bonner JL, Dickinson HG: Anther dehiscence in Lycopersicon esculentum Mill. I. Structural aspects. New Phytol. 1989, 113: 97-115. 10.1111/j.1469-8137.1989.tb02399.x.View ArticleGoogle Scholar
- Hua SJ, Meng HB, Wang XD, Jiang LX: Cytological and molecular mechanism of plant anther dehiscence. Chin J Cell Biol. 2007, 29: 389-393.Google Scholar
- Cecchetti V, Altamura MM, Falasca G, Costantino P, Cardarelli M: Auxin regulates Arabidopsis anther dehiscence, pollen maturation, and filament elongation. Plant Cell. 2008, 20 (7): 1760-1774. 10.1105/tpc.107.057570.PubMed CentralView ArticlePubMedGoogle Scholar
- Wilson ZA, Song J, Taylor B, Yang C: The final split: the regulation of anther dehiscence. J Exp Bot. 2011, 62 (5): 1633-1649. 10.1093/jxb/err014.View ArticlePubMedGoogle Scholar
- Zhou SR, Wang Y, Li WC, Zhao ZG, Ren YL, Wang Y, Gu SH, Lin QB, Wang D, Jiang L, Su N, Zhang X, Liu LL, Cheng ZJ, Lei CL, Wang JL, Guo XP, Wu FQ, Ikehashi H, Wang HY, Wan JM: Pollen semi-sterility1 encodes a kinesin-1-like protein important for male meiosis, anther dehiscence, and fertility in rice. Plant Cell. 2011, 23: 111-129. 10.1105/tpc.109.073692.PubMed CentralView ArticlePubMedGoogle Scholar
- Nelson MR, Band LR, Dyson RJ, Lessinnes T, Wells DM, Yang C, Everitt NM, Jensen OE, Wilson ZA: A biomechanical model of anther opening reveals the roles of dehydration and secondary thickening. New Phytol. 2012, 196 (4): 1030-1037. 10.1111/j.1469-8137.2012.04329.x.PubMed CentralView ArticlePubMedGoogle Scholar
- Bots M, Vergeldt F, Wolters-Arts M, Weterings K, Van-As H, Mariani C: Aquaporins of the PIP2 class are required for efficient anther dehiscence in tobacco. Plant Physiol. 2005, 137: 1049-1056. 10.1104/pp.104.056408.PubMed CentralView ArticlePubMedGoogle Scholar
- Rehman S, Yun SJ: Developmental regulation of K accumulation in pollen, anthers, and papillae: are anther dehiscence, papillae hydration, and pollen swelling leading to pollination and fertilization in barley (Hordeum vulgare L.) regulated by changes in K concentration?. J Exp Bot. 2006, 57: 1315-1321. 10.1093/jxb/erj106.View ArticlePubMedGoogle Scholar
- Castro AJ, Clément C: Sucrose and starch catabolism in the anther of Lilium during its development: a comparative study among the anther wall, locular fluid and microspore/pollen fractions. Planta. 2007, 225 (6): 1573-1582. 10.1007/s00425-006-0443-5.View ArticlePubMedGoogle Scholar
- Ito T, Ng KH, Lim TS, Yu H, Meyerowitz EM: The homeotic protein AGAMOUS controls late stamen development by regulating a jasmonate biosynthetic gene in Arabidopsis. Plant Cell. 2007, 19 (11): 3516-3529. 10.1105/tpc.107.055467.PubMed CentralView ArticlePubMedGoogle Scholar
- Ye Q, Zhu W, Li L, Zhang S, Yin Y, Ma H, Wang X: Brassinosteroids control male fertility by regulating the expression of key genes involved in Arabidopsis anther and pollen development. Proc Natl Acad Sci USA. 2010, 107 (13): 6100-6105. 10.1073/pnas.0912333107.PubMed CentralView ArticlePubMedGoogle Scholar
- Rieu I, Wolters-Arts M, Derksen J, Mariani C, Weterings K: Ethylene regulates the timing of anther dehiscence in tobacco. Planta. 2003, 217: 131-137.PubMedGoogle Scholar
- Wang Y, Kumar PP: Characterization of two ethylene receptors PhERS1 and PhETR2 from petunia: PhETR2 regulates timing of anther dehiscence. J Exp Bot. 2007, 58: 533-544.View ArticlePubMedGoogle Scholar
- Matsui T, Omasa K, Horie T: Mechanism of anther dehiscence in rice (oryza sativa L.). Ann Bot. 1999, 84 (4): 501-506. 10.1006/anbo.1999.0943.View ArticleGoogle Scholar
- Sanders PM, Lee PY, Biesgen C, Boone JD, Beals TP, Weiler EW, Goldberg RB: The Arabidopsis DELAYED DEHISCENCE1 gene encodes an enzyme in the jasmonic acid synthesis pathway. Plant Cell. 2000, 12: 1041-1061.PubMed CentralView ArticlePubMedGoogle Scholar
- Nagpal P, Ellis CM, Weber H, Ploense SE, Barkawi LS, Guilfoyle TJ, Hagen G, Alonso JM, Cohen JD, Farmer EE, Ecker JR, Reed JW: Auxin response factors ARF6 and ARF8 promote jasmonic acid production and flower maturation. Development. 2005, 132: 4107-4018. 10.1242/dev.01955.View ArticlePubMedGoogle Scholar
- Matsui T, Omasa K, Horie T: High temperature at flowering inhibits swelling of pollen grains, a driving force of thecae dehiscence in rice (Oryza sativa L). Plant Prod Science. 2000, 3: 430-434. 10.1626/pps.3.430.View ArticleGoogle Scholar
- Li WB, Wang H, Hang FS: Effects of silicon on anther dehiscence and pollen shedding in rice under high temperature stress. Acta Agron Sin. 2005, 31: 134-136.Google Scholar
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.