Secondary Growth in Plants

Origin and distribution of xylem.

Origin and distribution of xylem; Components of xylem vessels secondary growth in dicotyledonous plants should be treated; The activities of cambium; origin and activity; cork cambium; secondary cortex should be emphasized in respect of wood formation and annual rings in plants; Emphasis should be laid on the origin of cambium; structure and cell types; Ray initials: size; variation; cell arrangement (stored and non-stored); The uniseriate and multiseriate concepts of cambium structure; Importance of cambium; The dimensions of wood; groups of wood (soft and hard wood); Apotracheal and paratracheal wood nature - Rays in hard and soft woods; General studies on the nature and structure of pits as found in hard and soft woods; fibre and vessels; Significance of pit and pit membranes; Cambia and cambial activity in both angiosperm and gymnosperms; Physiology of cambial activity; metabolism of cambium (enzymes activity; temperature; soil nutrient; light intensity and photoperiodism effect on cambial activity); Uses in wood structure and utilization