Plant Anatomy Roots Part 2 Objectives Topics n

Plant Anatomy Roots Part 2

Objectives Topics n n n Taproot system Xylem/ Phloem Healthy Roots Root Tuber Fibrous root system n n n Understand what healthy roots look like Identify the internal layers of a root Know the different types of root systems

Layers of Cells in the Root n n n A. Cortex – this is where the root stores the food produced by the leaves B. Endodermis –controls the movement of water and minerals into the xylem and phloem C. Pericycle – a layer found inside the endodermis which may produce lateral roots

n D. Vascular cylinder – forms the central cylinder of the root; it is made out of two secondary transport tissues 1. Xylem – carries the water taken in by the root up the plant to the stems and leaves n 2. Phloem – carries the food produced by the leaves down to the roots to be stored n

Internal Layers of the Root Lateral Root Vascular Cylinder Xylem Phloem Pericycle Endodermis Cortex Root Hairs

What Are the Two Types of Root Systems? n Plant root systems are organized in two basic ways n Taproot n One main root n Ex. Carrot n Their roots reach far into the ground; they can be several feet long.

Examples of Taproots Carrot Beet Sweet potato

Root Tubers n Another form of root that produce a large food storage root n n Sweet Potato Used in propagation.

n Fibrous Root No primary root-made of many roots of similar size n EX: Grasses, n n Fibrous root system of grass They usually never grow below the first 6 -12 inches of soil

What Does a Healthy Root System Look Like? n n A healthy root system is white or nearly white in color and smells fresh, or earthy If roots are black, brown, or dark orange and smell rotten or sour, the root system is having some problems

Keeping a Healthy root n Proper Watering n If in pots, be sure that there are drainage holes in the bottom for extra water to drain n Water plant till soil is saturated and water drips out of the drainage holes n This encourages the roots to grow through the entire pot n Allow the pot to dry out slightly between watering n Too much water is a common cause of root death