Key words: Astragalus, endemic, lateral meristem
, micropropagation, callus induction.
In plants, new cells are produced only in apical meristem and lateral meristem
. Those cells, which do not remain in these meristematic areas are thought to go through the G1 portion of interphase activities but are thought not to replicate their chromosomes or produce specific materials for mitosis.
Data from development and genetics show that the spikelet pair is actually a small branch complex; one branch produces a single lateral meristem
and then terminates in a spikelet, as does the lateral meristem
Under low nutrient supply, nutrient levels available per lateral meristem
are generally insufficient to support overcompensation following shoot apex removal.
In grasses, the pair of spikelets is a shBr that produces a single lateral meristem
and then terminates in a spikelet.
Cell cycle rates may change sharply during ontogeny; for example, in juvenile plants of Polypodium both the axial and lateral meristem
zones show similarly high division activity, but the axial zone of adult plants has a low mitotic index with a cell cycle twice that of the lateral zone (Michaux-Ferriere, 1981b).
The promotion or repression of lateral meristems
located in the LIZ, that seem to be coordinated by environmental variables, fluctuates sometimes within the same species giving us specimens with axillary production and specimens lacking it (Rua & Grottola, 1997; Rua & Weberling, 1998).