Transverse of the root is occupied by 5-6 radiating

Transverse
section of root of male plant

 

Diagrammatic section shows outer cork,
middle cortex and central stealar region.

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Detailed transverse section (TS) of root
is almost circular to oval with the wavy outline. The outermost tissue – cork
appears as a narrow strip consists of 3-4 rows of thin walled, rectangular to
slightly tangentially elongated cork cells filled with oil globule, starch
grain and brown content. large extents of

The cortex region is impartially wide
and made up of paranchyma cell which are large in sized, and rounded to oblong
in shape. The cell walls of the peripheral rows are slightly thickened but not
lignified. Most of the cells are heavily loaded with globular or oval shaped,
simple to compound starch grains. Many secretory cells filled with large
yellowish brown globules are scattered in cortex. Centre pith of the root is
occupied by 5-6 radiating narrow strips of vascular tissues called stealar
region having their wider ends towards periphery. The cells combining the pith
are thin walled, polygonal in shape, and fill full of starch grains. Outside
the pith, evenly spaced six groups of primary xylem bundles are present. In
each vascular strip the xylem is composed of xylem vessels and xylem parenchyma
surrounded with strong woody fibres. Wider end of xylem is crowned with a
hemispherical strip of phloem. A strip of cambium consisting one or two rows of
narrow thin walled rectangular cell is present between xylem and phloem. The
phloem is composed of many sieve tubes with their companion cells that can be
distinctly made out towards the inner region of the phloem and small thin
walled polygonal parenchyma cells. The outer border of the phloem is limited by
a row of pericyclic cells found just inner to the endodermis. Medullary rays
are six to seven broadly distributed with their wider ends at the periphery and
alternating with the radiating bands of vascular tissue. Each ray is having
eight to ten thin walled cubical to slightly radically elongated cells and
arranged in radial rows and extended from pith to endodermis; heavily loaded
with starch grains and few cells have oil globules.