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Stenospermocarpy
Stenospermocarpy is the biological mechanism that produces parthenocarpy (seedlessness) in some fruits, notably many table grapes. In stenospermocarpic fruits, normal pollination and fertilization are still required to ensure that the fruit 'sets', i.e. continues to develop on the plant; however subsequent abortion of the embryo that began growing following fertilization leads to a near seedless condition. The remains of the undeveloped seed are visible in the fruit. Most commercial seedless grapes are sprayed with gibberellin to increase the size of the fruit and also to make the fruit clusters less tightly packed. A new cultivar, 'Melissa', has naturally larger fruit so does not require gibberellin sprays. Grape breeders have developed some new seedless grape cultivars by using the embryo rescue technique. Before the tiny embryo aborts, it is removed from the developing fruit and grown in tissue culture until it is large enough to survive on its own. Embryo rescue allows the cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenocarpy
In botany and horticulture, parthenocarpy is the natural or artificially induced production of fruit without fertilisation of ovules, which makes the fruit seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds are actually aborted while they are still small. Parthenocarpy (or stenospermocarpy) occasionally occurs as a mutation in nature; if it affects every flower, the plant can no longer sexually reproduce but might be able to propagate by apomixis or by vegetative means. Examples of this include many citrus varieties that undergo nucellar embryony for reproduction, instead of solely sexual reproduction, and can yield seedless fruits. However, parthenocarpy of some fruits on a plant may be of value. Up to 20% of the fruits of wild parsnip are parthenocarpic. The seedless wild parsnip fruit are preferred by certain herbivores and so serve as a "decoy defense" against seed predation. Utah juniper has a similar defense against bird feeding. The ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Grapes
Table grapes are grapes intended for consumption while fresh, as opposed to grapes grown for wine production, juice production, or for drying into raisins. ''Vitis vinifera'' table grapes can be in the form of either seeded or non-seeded varietals and range widely in terms of colour, size, sweetness and adaptability to local growing conditions. Common commercially available table grape varieties such as Sultana (grape), Thompson Seedless and Flame Seedless are favoured by growers for their high yield and relative resistance to damage during shipment. Other less common varietals such as Cotton Candy grapes, Cotton Candy, Kyoho (grape), Kyoho or Pione (grape), Pione are custom hybrids bred for size, appearance and specific flavour characteristics. Market characteristics Chile, Peru, the United States, China, Turkey, Spain, South Africa and Australia are all major producers and exporters of table grapes. World table grape production in 2016 is estimated by the United States Departm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma, it germinates and develops a pollen tube which grows down the style until it reaches an ovary. Its two gametes travel down the tube to where the gametophyte(s) containing the female gametes are held within the carpel. After entering an ovum cell through the micropyle, one male nucleus fuses with the polar bodies to produce the endosperm tissues, while the other fuses with the ovule to produce the embr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Processes such as insemination or pollination which happen before the fusion of gametes are also sometimes informally called fertilisation. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation. History In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic. In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibberellin
Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of plant hormone. It is thought that the selective breeding (albeit unconscious) of crop strains that were deficient in GA synthesis was one of the key drivers of the "green revolution" in the 1960s, a revolution that is credited to have saved over a billion lives worldwide. History The first inroads into the understanding of GAs were developments from the plant pathology field, with studies on the ''bakanae'', or "foolish seedling" disease in rice. Foolish seedling disease causes a strong elongation of rice stems and leaves and eventually causes them to topple over. In 1926, Japanese scientist Eiichi Kurosawa identified that foolish seedling disease was caused by the fungus ''Gibberella fujikuroi.'' Later work at the University of Tokyo sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars. Horticulturists generally believe the word ''cultivar''''Cultivar'' () has two meanings, as explained in ''Formal definition'': it is a classification category and a taxonomic unit within the category. When referring to a taxon, the word does not apply to an individual plant but to all plants that share the unique characteristics that define the cultivar. was coined as a term meaning "cultivated variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tissue Culture
Tissue culture is the growth of tissues or cells in an artificial medium separate from the parent organism. This technique is also called micropropagation. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar. Tissue culture commonly refers to the culture of animal cells and tissues, with the more specific term plant tissue culture being used for plants. The term "tissue culture" was coined by American pathologist Montrose Thomas Burrows. Historical use In 1885 Wilhelm Roux removed a section of the medullary plate of an embryonic chicken and maintained it in a warm saline solution for several days, establishing the basic principle of tissue culture. In 1907 the zoologist Ross Granville Harrison demonstrated the growth of frog embryonic cells that would give rise to nerve cells in a medium of clotted lymph. In 1913, E. Steinhardt, C. Israeli, and R. A. Lambert grew vaccinia virus in fragments of guinea pig corneal tiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thompson Seedless
The sultana is a "white" (pale green), oval seedless grape variety also called the sultanina, Thompson Seedless (United States), Lady de Coverly (England), and oval-fruited Kishmish (Iraq, Iran, Israel, Palestine, Pakistan, Afghanistan, India). It is also known as İzmir üzümü (grape of İzmir) in Turkey since this variety has been extensively grown in the region around İzmir. It is assumed to originate from Asia Minor, which later became part of the Ottoman Empire. In some countries, especially Commonwealth countries, the name ''sultana'' is used for the raisin made from it or larger seedless grapes; such ''sultana raisins'' are often called sultanas or sultanis. History American sultana grapes are almost invariably Thompson Seedless, a name that refers to William Thompson, a viticulturist who was an early grower in California and is sometimes credited with introducing the variety. According to the US Code of Federal Regulations, the two names are synonymous. Virtually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomcord (grape)
Thomcord is a seedless table grape variety and a hybrid of the popular Thompson Seedless or Sultanina grape (a ''Vitis vinifera'' variety) and Concord grape (a ''Vitis labrusca'' variety). Thomcord was developed in 1983 by Californian grape breeders working for the Agricultural Research Service (ARS), an agency of the United States Department of Agriculture (USDA), as part of a test to better understand a new seedless grape breeding procedure. Its aromatic, " labrusca" flavor is similar to that of Concord, but mellowed by the mild, sweet taste from Thompson Seedless. Thomcord grows well in hot, dry climates, ripens between late July and mid-August, and tolerates powdery mildew. It is a productive variety, yielding an average of of grapes per vine, but has produced as much as per vine in grower trials. The berries weigh between and have a medium-thick, blue-black skin that adheres to the fruit, unlike Concord, which has a thick skin that can slip off the pulp easily. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Grape Varieties
This list of grape varieties includes cultivated grapes, whether used for wine, or eating as a table grape, fresh or dried (raisin, currant, sultana). For a complete list of all grape species including those unimportant to agriculture, see Vitis. The term ''grape variety'' refers to cultivars rather than actual botanical varieties according to the International Code of Nomenclature for Cultivated Plants, because they are propagated by cuttings and may have unstable reproductive properties. However, the term ''variety'' has become so entrenched in viticulture that any change to using the term ''cultivar'' instead is unlikely. Single species grapes While some of the grapes in this list are hybrids, they are hybridized within a single species. For those grapes hybridized across species, known as interspecific hybrids, see the section on multispecies hybrid grapes below. ''Vitis vinifera'' (wine) Red grapes White grapes Rose Grapes ''Vitis vinifera'' (table) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seedless Fruit
A seedless fruit is a fruit developed to possess no mature seeds. Since eating seedless fruits is generally easier and more convenient, they are considered commercially valuable. Most commercially produced seedless fruits have been developed from plants whose fruits normally contain numerous relatively large hard seeds distributed throughout the flesh of the fruit. Varieties Common varieties of seedless fruits include watermelons, tomatoes, grapes (such as Termarina rossa). Additionally, there are numerous seedless citrus fruits, such as oranges, lemons and limes. A recent development over the last twenty years has been that of seedless sweet peppers (Capsicum annuum). The seedless plant combines male sterility in the pepper plant (commonly occurring) with the ability to set seedless fruits (a natural fruit-setting without fertilizationWO/2008/152134 In male sterile plants, the parthenocarpy expresses itself only sporadically on the plant with deformed fruits. It has been repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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