Germinants with 4 cotyledons - does it mean something?

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Germinants with 4 cotyledons - does it mean something?

Post by MWP admin » Tue Nov 06, 2007 6:34 pm

I have plant of a Convolvus species under investigation and I need to cultivate the seeds in good growing conditions to study the growth habit. From 10 seeds, 2 germinated and both germinated with 4 cotyledons ???

Does this have an explanation? Hybrid? Mutation? Convolvulus characteristic?
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Do 4-cotyledons germinants mean something specific?
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Post by RB » Wed Nov 07, 2007 10:03 am

From my limited knowledge:

The seedlings of, say, Morning glory have 2 cotyledons, but they are very deeply lobed, each one has 2 fingers. Still, they are distinctly one (i.e. clearly just 2 coty's)

Maybe your particular species has them so deeply lobed that they are now subdivided into 2 leaflets.

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Post by MWP admin » Wed Nov 07, 2007 12:12 pm

That is one possible and feasible explanation, despite the cotyledon 'dissected' leaflets seem to be distinct as an own cotyledon. As you said I have seen some cotyledons of Convolvulaceae, and many show lobed cotyledons, though none as much as this.
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Post by Edwin Lanfranco » Thu Nov 15, 2007 8:41 pm

Although the norm is one (monocots) or two (dicots) cotyledons, there are anumber of cases where extra cotyledons are present; It is probably a mutation (in your case - since both seedlings have extra cotyledons. I have often seen Ranunculus species with 3 cotyledons

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Post by ROLCAM » Thu Nov 15, 2007 10:02 pm

Cotyledon, is the leafy portion of a plant's embryo. The embryo is the part of the seed from which a mature plant develops. It consists of a radicle (short root) and a plumule (short bud), connected by a hypocotyl (short shoot) that bears one or more cotyledons. Because they form within seeds, cotyledons also are known as seed leaves. If a peanut is split apart, the two halves are the cotyledons. The remaining parts of the peanut embryo can be seen where the cotyledons are attached to the embryonic stem.

Flowering plants, called angiosperms, have embryos with one or two cotyledons. Those with one cotyledon are known as monocotyledons or monocots. Monocots include bananas, pineapples, and corn. Most bear leaves with parallel veins and flower parts in multiples of three. Angiosperms with two cotyledons are called dicotyledons or dicots. They produce leaves with a netlike pattern of veins and flower parts in multiples of four or five. Beans, squashes, and tomatoes are common dicots. Gymnosperms (nonflowering, woody plants) have embryos with two or more cotyledons, depending on the type of plant. Such needleleaf, cone-bearing trees as pines and hemlocks are gymnosperms.

Cotyledons have various functions. In some seeds, such as those of cereal grains, the cotyledon absorbs stored food from the endosperm (food storage tissue) of the seed. In other seeds, including those of peas and beans, the stored food is first absorbed by the developing embryo and then deposited in the fleshy cotyledons. When the seed of a pea sprouts, the cotyledons remain underground. In beans, however, the cotyledons appear above the ground and function briefly in photosynthesis .
Other cotyledons, such as those of morning-glories, resemble regular leaves in appearance and function.
Roland Camilleri B.Ec. FCPA.

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Post by MWP admin » Thu Nov 15, 2007 10:11 pm

The Convolvulus has formed 7 adult leaves and the cotyledons are still strong. The hair is sericeous like C. oleifolius, while the parent plant had the form of C. cantabrica. What is strange is that I collected some 100 seeds randomly from different specimens of which I randomly sowed 10-12

2 have germinated from 10 that I sowed and both had 2 pairs of cotyledons (or 4 cots. if your prefer). I feel the coincidence is too big that both are mutations.

I will follow the plant and document it.
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Post by Edwin Lanfranco » Thu Nov 15, 2007 11:13 pm

The fact that both seedlings has extra cotyledons actually supports the possibility that this may be due to mutation. Because once a mutation appears, it becomes heritable. Thus very probably the parent plant/s were the original mutants, or themselves the the offspring of mutants. If the mutation is a dominant gene, it will appear in all offspring

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