What is plastochron periodicity?
periodically, and the period between initiation of. successive leaves has been termed a plastochron. This term was proposed by Askenasy (1880) to. designate the interval of time between formation. of two successive internode cells in Nitella flexilis.
What is plastochron in plants?
A plastochron is defined as the time interval between two successive recurring events during the growth of plant shoots, such as leaf initiation.
Who introduced the idea of plastochron ratio?
The plastochron index (PI) introduced by Erickson and Michelini in 1957 is one such concept, which provided a solution to a long-standing problem, of how to measure time in growing plant populations, such that the occurrence of critical developmental events could more readily be detected, compared, and analyzed.
What is a Phyllochron interval?
The phyllochron interval (PI) is defined as the TT between the appearance of successive fully expanded leaves (or leaf tips) on a stem.
What is leaf gap in plant?
A leaf gap is a space in the stem of a plant through which the leaf grows. The leaf is connected to the stem by the leaf trace, which grows through the leaf gap. The leaf gap is a break in the vascular tissue of a stem above the point of attachment of a leaf trace.
What is leaf trace in plants?
A leaf trace is a thin vascular bundle in the stem, extending between its connection with a leaf and that with another vascular unit in the stem4. The leaf traces originate at the margin of the pith and bifurcate once or twice, or persist as a single vascular bundle extension.
Why is the stomata on the underside of the leaf?
This is an adaptation to prevent excess water loss. Transpiration is the loss of water through stomata, so, more stomata are found on the lower surface to prevent excessive loss of water. …
When describing for growth a Phyllochron is?
Wilhelm and McMaster (1995) defined phyllochron as the time elapsing between the visual appearance of two successive leaf tips, and the plastochron as the time elapsing between the production of two successive phytomers at the growing point.
What is the function of Casparian strip?
The Casparian strip is a water-impermeable sealing that fills the space between cells of the root endodermis. The only way for water and solutes to pass this barrier is to enter an endodermal cell.
Who proposed quiescent cell theory?
Frederick Albert Lionel Clowes
These cells divide either very slowly or not at all, functioning as a stem cell reservoir. The quiescent centre theory for demonstrating apical organisation in root was proposed by Frederick Albert Lionel Clowes (FAL Clowes).
How leaf gaps are formed?
(also lacuna), a break in the central cylinder, or stele, of a plant stem where the vascular bundles branch off into the leaf. It is formed over the leaf trace that extends from the stele.