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  • 鲜花植物种子 -- -- 先进

    Datura Stramonium

    Seeds: Developed Ovules
    ::种子:发达的Ovulles

    A seed is a ripened ovule , which has three functions:
    ::种子是一种结裂的卵卵,有三种功能:

    1. early nourishment and protection of the offspring of
      ::早育和对后代的保护
    2. dispersal , to reduce and allow colonization of new habitats
      ::减少和允许新生境的殖民化
    3. dormancy , to promote optimal timing of germination
      ::宿舍,促进最佳的发孕时间

    In this section, we will discuss the first function – early nourishment and protection of offspring. The sections that follow will discuss dispersal and dormancy.
    ::本节将讨论第一个功能 — — 早期营养和保护后代。 以下各节将讨论分散和居住问题。

    Both gymnosperms and produce seeds; however, this discussion will focus on only one (admittedly large) group of seeds. Angiosperm seeds develop from ovules within the ovary , and have three parts: a seed coat encloses an embryo together with a stored food supply known as endosperm .
    ::但是,这次讨论将只侧重于一组(公认的大)种子。 血管种子从卵巢内的卵巢中产出卵巢,分三部分:一种种子大衣将胚胎与一种被称作内分泌物的储存食物供应连接在一起。

    In angiosperms, fruits enclose seeds. Seeds consist of a seed coat, embryo, and endosperm food supply.
    In angiosperms, fruits enclose seeds. Seeds consist of a seed coat, embryo, and endosperm food supply.

    The embryo is an immature plant that develops from the zygote , itself a product of of an egg by a . Within the ovule, the zygote divides by to form “seed leaves” or  cotyledons , a primordial root, the radicle , and an embryonic divided into two parts – the epicotyl above the point of seed leaf attachment, and the hypocotyl below.
    ::胚胎是一种不成熟的植物,它从zygote中发展出来,而Zygote本身是卵子的产物。 在卵子中,zygote的分裂通过形成“种子叶 ” 或 共质叶、原始根、辐射和胚胎分为两部分 — — 即种子叶附着点之上的中枢,以及下面的低氧基。

    • Cotyledons serve as the first leaves of most new plants, or seedlings , immediately after germination. By the time of germination, they may contain the entire food supply of the seed; after this is exhausted, they may disappear – or turn green and function in for more than a year. angiosperms have one seed leaf; have two.
      ::在发芽后,科特勒顿作为大多数新植物或幼苗的第一批叶子。 在发芽时,它们可能包含种子的全部食物供应;在种子耗尽之后,它们可能消失 — — 或变绿并运行一年以上。 血管血管有一个种子叶;有两个。
    • The radicle is the first part of the embryo to emerge from the seed during germination. Growing out of the seed through the micropyle and downward into the soil , the radicle forms the primary root of the new plant.
      ::放射细胞是胚胎胚胎的第一部分,在发芽期间从种子中产生。通过微从种子中生长,然后向下进入土壤。 放射细胞是新植物的主要根。
    • After the radicle emerges, the hypocotyl lifts the growing shoot, often with the seed coat, upward. Above the seed leaves, the epicotyl grows the shoots and first true leaves of the young plant.
      ::核电极在核电极下层形成后,低氯基会将生长的射线提升到上方,通常还有种子大衣。 在种子叶上方,冰层会长出小植物的射线和第一副真叶子。

    If you enjoy coconut “meat”, popcorn, or bananas, you know the food value of endosperm – another critical investment in angiosperm offspring success. In angiosperms, endosperm develops from the fusion of a second sperm nucleus with the two polar nuclei of the female gametophyte , so the tissue it forms is triploid (3n). Endosperm serves as a food supply for the embryo and seedling; depending on the , it may be rich in oils, starch , and/or . In some species, the majority of the endosperm is absorbed by the developing embryo and stored in the cotyledons. Oaks, squash, sunflowers, peas, beans, and many other eudicots have no endosperm as mature seeds, but the cotyledons contain a great deal of stored food. Mature seeds of grasses, palms, most other monocots, and many eudicots contain separate endosperm for seedling at germination; the starches stored in grains such as corn, wheat, and rice are good examples. The importance of endosperm is underlined by the absolute dependence of dust-sized orchid seeds – which lack endosperm entirely- to work with mycorrhizal for nutrient absorption at the time of germination and for up to several years. Some orchids depend on the fungi for several years before they finally grow photosynthetic leaves.
    ::如果你享受椰子“肉 ” 、 爆米花或香蕉,你就会知道内分泌的食品价值 — — 也就是对血管移植后代的另一项重要投资 — — 在某些物种中,内分泌的多数被发育中的胚胎吸收,并储存在骨中。在血管移植中,内分泌从第二个精核与雌性植物的两个极地核核核融合而来,因此它所形成的组织是三联式的(三n)。内分泌是胚胎和幼苗的食品供应;取决于它可能富含石油、淀粉和/或。在某些物种中,内分泌的多数由发育中的胚胎吸收,并储存在骨中。橡皮骨、红花、豆、豆类和许多其他食类中,没有内分泌的内分泌,但内分泌含有大量食物。 草、棕榈、其他许多单体和许多外科的外科都含有不同的内分泌,在内分泌前的内分泌的内分泌的内分泌;在谷上储存的颗粒和绝对性种子的重要性,如玉米、直系、玉米、直系、谷系至谷系、谷系、直系、谷系、谷系、直系、谷系、谷系、谷系、谷系、谷系、谷系、直至谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系、谷系等。

    The seed coat develops from maternal tissue (usually two layers of integuments) surrounding the ovule. In some species, the seed coat is quite thin (as the papery skin surrounding a peanut). In other species, the seed coat is hard and thick; when fused to a hard endocarp (as in peaches and coconuts), it forms a highly resistant stone which is part fruit , part seed.
    ::种子大衣是从卵巢周围的母体组织(通常为两层内脏)形成的。 在有些物种中,种子大衣非常薄(如花生周围的纸质皮层 ) 。 在另一些物种中,种子大衣是硬的和厚的;当它被熔化成硬内脏(如桃子和椰子)时,它形成一种非常耐受的石块,作为部分水果和部分种子。

    Angiosperm seeds develop within ovaries as ovules containing maternal tissue – the integuments. Double fertilization produces the zygote (egg + one sperm nucleus) and endosperm (polar nuclei + a second sperm nucleus). As the ovule matures into a seed, the zygote develops into the embryo, consisting of cotyledon(s) (C) and hypocotyl (D), the endosperm (B) develops into a nutrient tissue food supply, and the integuments become the seed coat (A).
    Angiosperm seeds develop within ovaries as ovules containing maternal tissue – the integuments. Double fertilization produces the zygote (egg + one sperm nucleus) and endosperm (polar nuclei + a second sperm nucleus). As the ovule matures into a seed, the zygote develops into the embryo, consisting of cotyledon(s) (C) and hypocotyl (D), the endosperm (B) develops into a nutrient tissue food supply, and the integuments become the seed coat (A).

    Seed development begins immediately after fertilization. The endosperm divides rapidly to form tissue that provides food until after develop. The first division of the zygote establishes the polarity of the embryo, and the radicle, cotyledons, epicotyl and hypocotyl develop from this point. The seed coat may develop wings or tufts of hair that will facilitate dispersal when the seed is released, as will be discussed below.
    ::种子的生长从施肥后立即开始,内分泌迅速分裂成提供食物直至发育后的组织。 zygote的第一个分解确定了胚胎的两极性,以及从此开始的核子、核合苯、中链球和低氯基的发育。 种子外衣可能长出翅膀或长长发,在种子释放后会有利于传播,下文将讨论这一点。

    The early development of the embryo within the seed gives a distinct advantage in increased survival of offspring. Seed size varies from dust-sized orchid seeds to the 20 kg Seychelles coconut. Plant strategies balance the energy costs of seed size and number of seeds; fewer, larger seeds, each more likely to produce viable offspring vs. many smaller seeds, which offer a greater opportunity for successful dispersal, but less chance of survival for each seed. Fall-blooming plants often produce smaller seed because they require less time to mature. Annual plants often produce large quantities of small seeds, emphasizing dispersal over individual survivorship. Perennials can pool resources over a number of years to produce larger seeds, which with more energy reserves and a more well developed embryo, have a greater chance of producing strong, competitive offspring.
    ::种子中胚胎的早期发育在增加后代存活率方面具有明显的优势。种子大小从粉尘大小的兰花种子到20公斤塞舌尔椰子不等。植物战略平衡种子大小和种子数量的能源成本;更少、更大的种子,每个种子都更可能产生存活的后代相对于许多较小的种子,这为种子的成功散布提供了更大的机会,但却减少了生存机会。秋色植物往往生产较小的种子,因为它们需要较少的时间才能成熟。每年的植物往往生产大量的小种子,强调在个体生存能力之上的散布。 多年的植物可以汇集资源来生产更大的种子,而拥有更多能源储备和更发达的胚胎的种子则更有可能产生强大、更有竞争力的后代。

    Summary
    ::摘要

    • A seed is a ripened ovule which provides dispersal, dormancy, and a nutritional “head start” for offspring.
      ::种子是一种发芽的卵卵,为后代提供分散、住宿和营养“头开始”。
    • Seeds consist of three parts: an embryo, stored food, and a protective seedcoat.
      ::种子由三部分组成:胚胎、储存的食物和防护种子服。
    • The embryo develops from the zygote, a result of fertilization of egg cell by one sperm nucleus.
      ::胚胎从zygote产生,这是由一个精子核心对卵细胞施肥的结果。
    • Stored food is supplied by endosperm, which results when polar nuclei fuse with a second sperm nucleus.
      ::贮存食物由内骨膜供应,结果极地核与第二个精子核结合。
    • The seedcoat develops from the integuments which cover the ovule or embryo sac – maternal tissue.
      ::种子外套是从囊括卵巢或胚胎囊的内脏—— 母体组织—— 形成的。
    • Fall-blooming and annual plants produce many small seeds, which mature quickly and “cost” less energy.
      ::膨胀的植物和每年的植物生产许多小种子,这些种子迅速成熟,“成本”低,能量也低。
    • Perennials produce fewer, larger seeds which cost more energy but have a better chance to survive.
      ::每年生产的种子数量更少,规模更大,耗能更多,但生存机会更好。