Transverse section of lamina has a very thin cuticle on the epidermal cells, which are rectangular in outline and form a single layer. The mesophyll is differentiated into a palisade and spongy mesophyll (Fig.(Fig.12).12). Palisade layer is present on both upper and lower side beneath the epidermis. The upper epidermis has 5~7 layers of cells and the lower epidermis has 2~3 layers. Inside the palisade layer are densely staining material which may be supportive in nature (Fig.(Fig.12).12). The spongy mesophyll consists of a large number of air spaces surrounded by thin walls full of chloroplast. Sclereids are observed in cells facing air spaces. Vascular bundles are of two types, i.e. smaller and larger vascular bundles. Smaller vascular bundles are present in both upper and lower epidermis side; some of them are in contact with the epidermis. Each vascular bundle is collateral with xylem towards the lower epidermis side and phloem towards the upper epidermis side. Tracheary elements consist of tracheids, vessels, and parenchyma cells. Tracheary elements in smaller bundles are thin-walled and without usual secondary thickenings. The phloem consists of sieve tubes and companion cells. Bundle sheath extensions are also observable in smaller bundles (Fig.(Fig.12).12). Large vascular bundles are present in the leaf center and extend from one end to the other of the leaf (Fig.(Fig.12).12). Each vascular bundle is surrounded by a bundle sheath of parenchyma cells. Sclereids are observable in the palisade cells, and also in air spaces. Some bundles have cross connections. Measurements of cell sizes in leaves of control and experimental plants are shown in Table Table7.7. Statistical analysis showed that the textile wastewater had non-significant (P>0.05) effect on the palisade cells of leaves of the control and experimental plants, while all other cells were significantly (P
Transverse section of lamina has a very thin cuticle on the epidermal cells, which are rectangular in outline and form a single layer. The mesophyll is differentiated into a palisade and spongy mesophyll (Fig.(Fig.12).12). Palisade layer is present on both upper and lower side beneath the epidermis. The upper epidermis has 5~7 layers of cells and the lower epidermis has 2~3 layers. Inside the palisade layer are densely staining material which may be supportive in nature (Fig.(Fig.12).12). The spongy mesophyll consists of a large number of air spaces surrounded by thin walls full of chloroplast. Sclereids are observed in cells facing air spaces. Vascular bundles are of two types, i.e. smaller and larger vascular bundles. Smaller vascular bundles are present in both upper and lower epidermis side; some of them are in contact with the epidermis. Each vascular bundle is collateral with xylem towards the lower epidermis side and phloem towards the upper epidermis side. Tracheary elements consist of tracheids, vessels, and parenchyma cells. Tracheary elements in smaller bundles are thin-walled and without usual secondary thickenings. The phloem consists of sieve tubes and companion cells. Bundle sheath extensions are also observable in smaller bundles (Fig.(Fig.12).12). Large vascular bundles are present in the leaf center and extend from one end to the other of the leaf (Fig.(Fig.12).12). Each vascular bundle is surrounded by a bundle sheath of parenchyma cells. Sclereids are observable in the palisade cells, and also in air spaces. Some bundles have cross connections. Measurements of cell sizes in leaves of control and experimental plants are shown in Table Table7.7. Statistical analysis showed that the textile wastewater had non-significant (P>0.05) effect on the palisade cells of leaves of the control and experimental plants, while all other cells were significantly (P<0.05) reduced in size.
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