Introduction-to-Horticulture-园艺学介绍.ppt

Intro to Horticulture Parts of the plant and their functions Functions of leaves . External Leaf Structures Leaves are consist of petiole and blade Blade is comprised of veins and a midrib The veins of the leaf form its structural framework . Chloroplast Cells in the center of the leaf The chloroplast contains chlorophyll which gives the plants the green color Manufactures food for the plant though Photosynthesis Beginning of the food chain for all living things Respiration Plants respire 24 hours/day just as animals In this process they consume oxygen and give off oxygen What is the purpose of the stems? Two main Functions The movement of materials- water, minerals, food Support the leaves and reproductive structures Can be used for food storage Ex. Irish potato Internal Stem Structure What does the Xylem Carry Water and minerals travel up What about the Phloem Manufactured food travels down the plant What does the Cambium do? Separates the xylem and the phloem Thin, green, actively growing tissue located between the bark and the wood of a plant What is the difference in monocot and dicot, and why should I care? Dicot stem may continue to increase in diameter because the cambium builds new phloem cells on the outside and new xylem cells on the inside Ex. Trees Monocot have vascular bundles which contain both xylem and phloem and no cambium This would make it more limited in size Ex. corn Why should we care? The stems of some plants we use as food Irish potato and asparagus Others are used in building materials Lumber from the tree trunks Roots Roots function Anchor the plant and hold it upright Absorb water and minerals from the soil and conduct them to the stem Store large quantities of plant food Propagate or reproduce some plants Fibrous root vs. tap root Fibrous root system Much easier to transplant More spread out Tap root system Longer fewer roots End of root contains many root hairs What is the purpose of seeds? To continue the plant process There are two