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12 Cards in this Set
- Front
- Back
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Seedling |
Young plant from germination to the stage when the first true leaf is actively photo synthesizing |
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Root |
The lower end of the plant that originates from the radicle |
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Hypocotyle |
Region of the plant between the first root branch and the first node (below cotyledon) |
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First node |
Point of attachment for the cotyledons |
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Epicotyl |
Part of a plant above the cotyledon, not used after emergence because refer to specific part instead |
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1. Root 2. Hypocotyl 3. First node 4. Epicotyl |
4 Parts of Dicot Seedlings |
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Emergence |
Refers to the biological mechanism whereby the seedling becomes visible above ground after planting |
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1. Active hypocotyl 2. Active epicotyl |
Two Methods of Emergence |
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Active hypocotyl |
Method of seedling emergence that is most common among dicot crops, the hypocotyl elongates during seedling emergence (Ex: soybean, sunflower, flax) |
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1. The radicle breaks through the seedcoat, elongates, and roots develop as an anchor 2. Hypocotyl elongates forming a hypocotyl arch (penetrating structure), cotyledons pulled upwards, seed coat falls off 3. Elongation stops when the hypocotyl breaks through soil surface and reaches sunlight 4. The cotyledons expose first leaves and terminal bud, shrivel and fall off after food storage depleted (2-3 weeks) |
Growth stages of active hypocotyl |
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1. The radicle breaks through the seed coat and develops several branch roots 2. The epicotyl forms an arch to protect the terminal bud and develops hard tissue to penetrate the soil, two or three nodes above ground and two below 3. Epicotyl arch straightens on exposure to light , internodes below ground stop growing and leaves develop |
Growth stages of active epicotyl |
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1. seedling - young plant from emergence until the first leaves are developed 2. unifoliolate leaves - first true leaves have expanded above cotyledons 3. trifoliolate leaves - one trifoliolate leaf per node 4. bud - flower cluster are developing for axillary buds 5. flowering - flowers open so the petals are visible 6. pods - develop after fertilization 7. maturity - seeds are mature enough for harvest |
Growth stages for legumes |
