Epicarp tube cells

FIGURE 4.3 Microphotograph detailing the microstructure of the pericarp and aleurone layer of the sorghum caryopsis. E = epicarp M = mesocarp S = starch granules CC = epicarp cross cells T = epicarp tube cells SC = seed coat or testa A = aleurone cells P = peripheral endosperm (courtesy of C. McDonough and L. W. Rooney, Texas A M University). 

The Pericarp or ripened ovarian wall which, alike with all other grains, adheres firmly to the wall of the seed forming a portion of the skin of the grain. The pericarp comprises an outer epicarp of elongated cells with thin cuticle, a mesocarp of thicker walled cells without, becoming thinner within, and a layer of tube cells. 

Fig. 15.2. Longitudinal section of a wheat grain. I Pericarp, 1 epidermis (epicarp), 2 hypodermis, 3 tube cells, 4 seed coat (testa), 5 nucellar tissue, 6 aleurone layer, 7 outer starchy endosperm cells, 8 inner starchy endosperm cells, 9 germ and 10 scutellum...

The pericarp is the part of the kernel that covers the seed, and it contains several cellular layers. The main cellular layers are the epicarp, mesocarp, and endocarp. The endocarp is subdivided into intermediate, cross, and tube cells (Figure 4.3). Some cereal grains such as maize and sorghum also contain an external wax layer that has a protective role. The epicarp or epidermis is the outermost layer of the pericarp. The epicarp cells are elongated rectangles with thin cell walls. The mesocarp and endocarp vary in thickness and number of layers, depending on the type of... 

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See also in sourсe #XX -- [ ]

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