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Key message Low number of pistillate flowers in the tung tree is a major factor causing the low yield of tung fruits. The tung tree (Vernicia fordiiHemsl.), an economically important woody oil plant, produces excellent fast-drying...
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Key message Low number of pistillate flowers in the tung tree is a major factor causing the low yield of tung fruits. The tung tree (Vernicia fordiiHemsl.), an economically important woody oil plant, produces excellent fast-drying oil from the seeds which has been used as a protective finish on projects and surfaces for centuries. Knowledge of sex determination and flower development of tung trees is helpful for high-yield cultivation and breeding of new elite cultivars. However, studies on tung flower biology and ontogeny are still lacking. Here, we reported a comprehensive study of the flower biology and ontogeny of the tung tree, focusing on flower cycle, flower morphology and flower development. The inflorescence phenophases of monoecious tung trees were divided into 12 pivotal stages and used as a unique timeline to reference the events registered throughout the flower cycle. Histological studies on sporogenesis and gametogenesis were also conducted. Meanwhile, all the unique events throughout flower cycle were linked together to show the correlation between inflorescence development phenophases, pistillate and staminate flower stages and its embryological development. Tung trees in our plantation were grouped into three major types, i.e., monoecious, gynoecious and androecious trees which produced different number of fruits in each inflorescence. We propose that low number of pistillate flowers in the tung tree is a major factor causing the low yield of tung fruits, and that any measures increasing the number of pistillate flowers would effectively improve the yield of tung fruits.
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Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cycli...
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Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cyclic pattern of gregarious flowering after long vegetative periods. The flowering cycle has been described in very few species. The goal was to identify mass flowering events of woody bamboo species native to Argentina and neighboring areas, and to estimate the flowering cycle of each species. Sixteen species were surveyed: Chusquea culeou, C. deficiens, C. lorentziana, C. montana, C. quila, C. ramosissima, C. tenella, C. valdiviensis; Colanthelia rhizantha; Guadua chacoensis, G. paraguayana, G. trinii; Merostachys clausenii, M. multiramea, Rhipidocladum neumannii and R. racemiflorum. To reconstruct flowering dates, information from literature and herbarium collections was consulted and more than 990 records were gathered. Flowering cycles were estimated by recording the intervals between reported flowering events. Evidence of regular flowering cycles of ca. 30 years was found for most of the species considered. There is a remarkable concentration of flowering cycles about multiples of 15-16 years. Flowering synchrony among different species of woody bamboos was recorded for the first time in South America.
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Leaves and cotyledons of the terrestrial C4 plants, Bienertia cycloptera Bunge ex Boiss. and Suaeda aralocaspica (Bunge) Freitag & Schutze (Chenopodiaceae), accomplish C4 photosynthesis within individual chlorenchyma cells: each species having a unique means of intracellular spatial partitioning of biochemistry and organelles. In this study the chlorenchyma tissue in flowers and stems of these species was investigated. Flowers have an outer whorl of green tepals with a layer of chlorenchyma cells, which are located on the abaxial side, exposed to the atmosphere. Anatomical, immunocytochemical, western blots and starch analyses show that the chlorenchyma cells in tepals are specialised for performance of single-cell C4 photosynthesis like that in leaves. In the tepals of B. cycloptera, chlorenchyma cells have a distinctive central cytoplasmic compartment, with chloroplasts which contain Rubisco, separated by cytoplasmic channels from a peripheral chloroplast-containing compartment, with phosphoenolpyruvate carboxylase (PEPC) distributed throughout the cytoplasm. In the tepals of S. aralocaspica, chlorenchyma cells have chloroplasts polarised towards opposite ends of the cells. Rubisco is found in chloroplasts towards the proximal end of the cell and PEPC is found throughout the cytoplasm. Also, green stems of B. cycloptera have a single layer of the specialised C4 type chlorenchyma cells beneath the epidermis, and in stems of S. aralocaspica, chlorenchyma cells are scattered throughout the cortical tissue with chloroplasts around their periphery, typical of C3 type chlorenchyma. During reproductive development, green flowers become very conspicuous, and their photosynthesis is suggested to be important in completion of the life cycle of these single-cell C4 functioning species.....
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Leaves and cotyledons of the terrestrial C4 plants, Bienertia cycloptera Bunge ex Boiss. and Suaeda aralocaspica (Bunge) Freitag & Schutze (Chenopodiaceae), accomplish C4 photosynthesis within individual chlorenchyma cells: each species having a unique means of intracellular spatial partitioning of biochemistry and organelles. In this study the chlorenchyma tissue in flowers and stems of these species was investigated. Flowers have an outer whorl of green tepals with a layer of chlorenchyma cells, which are located on the abaxial side, exposed to the atmosphere. Anatomical, immunocytochemical, western blots and starch analyses show that the chlorenchyma cells in tepals are specialised for performance of single-cell C4 photosynthesis like that in leaves. In the tepals of B. cycloptera, chlorenchyma cells have a distinctive central cytoplasmic compartment, with chloroplasts which contain Rubisco, separated by cytoplasmic channels from a peripheral chloroplast-containing compartment, with phosphoenolpyruvate carboxylase (PEPC) distributed throughout the cytoplasm. In the tepals of S. aralocaspica, chlorenchyma cells have chloroplasts polarised towards opposite ends of the cells. Rubisco is found in chloroplasts towards the proximal end of the cell and PEPC is found throughout the cytoplasm. Also, green stems of B. cycloptera have a single layer of the specialised C4 type chlorenchyma cells beneath the epidermis, and in stems of S. aralocaspica, chlorenchyma cells are scattered throughout the cortical tissue with chloroplasts around their periphery, typical of C3 type chlorenchyma. During reproductive development, green flowers become very conspicuous, and their photosynthesis is suggested to be important in completion of the life cycle of these single-cell C4 functioning species..
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The genetic network resulting in the production of an inflorescence is complex, involving one or more pathways including the photoperiod, maturity, gibberellin and autonomous pathways, and induction and repression of genes along t...
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The genetic network resulting in the production of an inflorescence is complex, involving one or more pathways including the photoperiod, maturity, gibberellin and autonomous pathways, and induction and repression of genes along the pathways. Understanding the cyclic expression profile of genes involved with photoperiod perception and floral pathway induction in sugarcane, an intermediate-short day plant (ISD), is crucial for identifying key genes and understanding how the profile changes in response to floral induction signals under decreasing daylengths. Homologues of 21 genes, and some gene alleles, associated with photoperiod perception and the flower induction pathway were examined in sugarcane variety Q174 over a 24-h light-dark cycle. The strongest expression of these genes was seen in the immature spindle leaves and levels of expression generally decreased with increasing leaf age. Significant changes in gene expression levels during a 24-h cycle were observed for 16 of the 21 genes tested. We have now defined an important baseline for expression patterns over a 24-h cycle in non-inductive conditions in sugarcane. These results can be utilised to select the optimal time for detecting changes during floral induction, differences between varieties that are responsive/non-responsive to photoperiod induction, and to identify genes that may be manipulated to enhance or inhibit flowering.
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Pollen viability and germination were observed in six species of neotropical Araccae. In Anaphyllopsis americana (Engl.) A. Hay, 50% of pollen grains remain viable after 70 h following dehiscence, and it takes over 210 h for total...
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Pollen viability and germination were observed in six species of neotropical Araccae. In Anaphyllopsis americana (Engl.) A. Hay, 50% of pollen grains remain viable after 70 h following dehiscence, and it takes over 210 h for total loss of viability to occur. In Montrichardia arborescens (L.) Schott, approximately 50% of pollen grains are not viable after 24 h, and no germination occurs after 36 h. Monstera adansonii Schott and Philodendron pedatum (Hook.) Kunth have the lowest initial pollen viability (40%-55%) and lose half of this viability after approximately 30 h. Pollen grains of Monstera adansonii remain viable for at least 60 h and that of P. pedatum for approximately 40 h, and constitute another group with a similar viability pattern. In Philodendron melinonii Brongn. ex Regel and Philodendron solimoesense A.C. Sm., pollen loses 50% of its viability after 24 h, but remains viable for at least 48 h. The percentage of viability decreases in a pattern from species having a long flowering cycle and small pollen grains (A. americana) to species with a short flowering cycle and large pollen grains (M. arborescens).
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Pollen viability and germination were observed in six species of neotropical Araccae. In Anaphyllopsis americana (Engl.) A. Hay, 50% of pollen grains remain viable after 70 h following dehiscence, and it takes over 210 h for total...
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Pollen viability and germination were observed in six species of neotropical Araccae. In Anaphyllopsis americana (Engl.) A. Hay, 50% of pollen grains remain viable after 70 h following dehiscence, and it takes over 210 h for total loss of viability to occur. In Montrichardia arborescens (L.) Schott, approximately 50% of pollen grains are not viable after 24 h, and no germination occurs after 36 h. Monstera adansonii Schott and Philodendron pedatum (Hook.) Kunth have the lowest initial pollen viability (40%-55%) and lose half of this viability after approximately 30 h. Pollen grains of Monstera adansonii remain viable for at least 60 h and that of P. pedatum for approximately 40 h, and constitute another group with a similar viability pattern. In Philodendron melinonii Brongn. ex Regel and Philodendron solimoesense A.C. Sm., pollen loses 50% of its viability after 24 h, but remains viable for at least 48 h. The percentage of viability decreases in a pattern from species having a long flowering cycle and small pollen grains (A. americana) to species with a short flowering cycle and large pollen grains (M. arborescens).
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The flowering characteristics of Phyllostachys heteroclada were studied. The occurrence of flowering was random in a year, mostly between November and May, which led to death of the bamboo clumps. Environmental factors, such as il...
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The flowering characteristics of Phyllostachys heteroclada were studied. The occurrence of flowering was random in a year, mostly between November and May, which led to death of the bamboo clumps. Environmental factors, such as illumination period, temperature and humidity had significant influence on flowering.
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Background: Feijoa (Acca sellowiana (O. Berg)) was initially introduced as an ornamental plant, but nowadays, it is widely cultivated for the numerous beneficial properties of its edible fruits. Feijoa flowers have been included i...
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Background: Feijoa (Acca sellowiana (O. Berg)) was initially introduced as an ornamental plant, but nowadays, it is widely cultivated for the numerous beneficial properties of its edible fruits. Feijoa flowers have been included in the list of edible flowers, but despite this, they are still considered niche products due to consumer skepticism and lack of publicity. Methods: This study evaluated the physicochemical traits, antioxidant system, and ascorbate-glutathione cycle in feijoa flowers at five flowering stages based on the Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie (BBCH) scale. Results: The results showed that the optimal stage to harvest feijoa flower is the F2 stage characterized by high bioactive compounds content. Furthermore, the enzymes involved in oxidative stress and the ascorbate-glutathione cycle showed different trends during the flowering stages. Conclusions: This study provides new evidence to understand the possible role of bioactive compounds and ascorbate-glutathione cycle in the regulation of flower development, defining the optimal stage to harvest flowers.
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From a temporal viewpoint, air pollution has significant daily patterns/cycles of behaviour. These cycles are conditioned by anthropogenic and natural phenomena. In both cases, a detailed observation and an understanding of the da...
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From a temporal viewpoint, air pollution has significant daily patterns/cycles of behaviour. These cycles are conditioned by anthropogenic and natural phenomena. In both cases, a detailed observation and an understanding of the daily cycles rules or daily patterns of air pollution can be significant and at the same time can contribute to more effective measures to reduce the harmful impact of air pollution on human health. In this paper the new sunflower diagram is presented. The key advantage of the sunflower diagram is the ease of understanding the result and the ability to present information in the form of a graphic pattern, allowing the user to quickly understand the content. Using the sunflower diagram, we will present an analysis of the meteorological parameters that are important for understanding air pollution and air-pollution data for different locations in Slovenia.
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Flowers, microsporogenesis and microgametogenesis of Excentrodendron hsienmu in opening-functional flowers and non-opening flowers were studied to investigate the evolutionary relationships of Excentrodendron. E. hsienmu is a dioe...
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Flowers, microsporogenesis and microgametogenesis of Excentrodendron hsienmu in opening-functional flowers and non-opening flowers were studied to investigate the evolutionary relationships of Excentrodendron. E. hsienmu is a dioecious species that blossoms every 3-4 years, although large numbers of flower buds develop every year. The anther is tetrasporangiate, the tapetum is of the secretory type, the microspore tetrads are mainly tetrahedral, and the pollen grains are two-celled when shed. Four tosix microsporocytes are seen on the transverse section of the anthers, and cytokinesis is simultaneous. The development of the anther wall conforms to the basic type and the anther wall is five or six cells thick, with a fibrous endothecium. The difference between the opening-functional and the non-opening flowers is mainly in the thickness of the anther wall. Early megasporogenesis in staminate flowers up to megaspore mother cell or megaspore tetrads has been observed. Excentrodendron shares with Dombeyeae only plesiomorphic features, but differs in anther wall development type and thickness. Most features of Excentrodendron are shared with Pterospermum, including such synapomorphic features as basic type of anther wall development, five- to six-cell-thick anther wall, biseriate tapetum at some places, and degeneration of microsporocytes, suggesting placement near Pterospermum.
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