I have posted this message in two parts.
I think some terms involved directly or indirectly in plants pigments production must be correctly defined. If some of us don't do it, certainly will generate confusions for most of us.
Thus,
1. Chlorophyll
Is a green pigment that have important task in photosynthesis. There are two types: Chlorophyll A and Chlorophyll B.
2. Compromising in the synthesis of chlorophyll
Failure to produce chlorophyll can be the result of genetic factors (albinism) or chimaeral growth or growth of plants in darkness (etiolation).
3. Albinism
Albinism is a genetic disoder inherited as a Mendelian recessive character. As in animals, albinism in plants is caused by lack of pigment. In animals the lack is melanin and in plants the lack is chlorophyll. In animals the lack of melanin isn't fatal.
4. Vegetal albinism
The lack of chlorophyll is fatal in plants that normally have it. A number of plant species have a recessive allele for albinism. Homozygous albino individuals are unable to synthesize chlorophyll. Without chlorophyll, the albino plant has no way to manufacture the food needed for survival and growth to maturity. Albino seedlings usually live only about a week. Note that is a genetic disorder only in plants that normally don't possess it, because have exceptions in orchids that normally chlorophyll is lacking like in subterrain Rhizanthella gardneri R. S. Rogers. Thus, albinism is a complete absence of green colour resulting from genetic factors.
5. Vegetal albino
Is an affected individual, bearer of the gene of the vegetable albinism in homozigose. Albino seedlings result from the combination in the seed of genes that were recessive in the parent plants. Frequently a single cell or, in some cases, in a group of cells can occur albinism mutation, and in these cases the plant survive because the rest of the plant from which the albino stem grows can be normal, so this affected tissues receive normally nutrients from the other parts of plants unaffected. This condition is known as partial albinism and isn't inherited.
6. Chlorophyll deficient mutants
Some plants have a reduced amount of the green pigment chlorophyll and are considered chlorophyll deficient mutants. These plants survive but grow less vigorously than a normal, "green".
With regards,
Americo Docha Neto
Poços de Caldas MG
Brazil
Continue in the next part
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