Introduction to Botany. Lecture 25 Alexey Shipunov Minot State University November 2, 2015 Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 1 / 33
Outline 1 Questions and answers 2 Stem and shoot Anatomy of the primary stem Components of shoot Phyllotaxis 3 Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 2 / 33
Outline 1 Questions and answers 2 Stem and shoot Anatomy of the primary stem Components of shoot Phyllotaxis 3 Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 2 / 33
Outline 1 Questions and answers 2 Stem and shoot Anatomy of the primary stem Components of shoot Phyllotaxis 3 Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 2 / 33
Questions and answers Previous final question: the answer What is a procambium? Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 3 / 33
Questions and answers Previous final question: the answer What is a procambium? Tissue which appears between cortex and pith and makes xylem and phloem. Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 3 / 33
Stem and shoot Anatomy of the primary stem Stem and shoot Anatomy of the primary stem Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 4 / 33
Stem and shoot Vascular bundle (monocot) Anatomy of the primary stem Corn (Zea mays) mature stem cross-section showing single vascular bundle, Brightfield (LM 400) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 5 / 33
Stem and shoot Vascular bundle (asterid) Anatomy of the primary stem Wild Sunflower (Helianthus sp.) with nearly mature vascular bundle (LM 35) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 6 / 33
Stem and shoot Origin of vascular bundles Anatomy of the primary stem Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 7 / 33
Vascular bundles Stem and shoot Anatomy of the primary stem Vascular bundles connect leaves and stems In many plants, they form ring on the cross-section of stem ( dicot stem) Monocot stems usually have dispersed vascular bundles Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 8 / 33
Stem and shoot Vascular bundles and leaf traces Anatomy of the primary stem Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 9 / 33
Monocot stem Stem and shoot Anatomy of the primary stem Corn (Zea mays) stem (LM 4) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 10 / 33
Steles Stem and shoot Anatomy of the primary stem Stele is an overall configuration of primary vascular system of plant stem The most important kinds of steles are: protostele, solenostele, eustele and ataktostele* Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 11 / 33
Diversity of steles Stem and shoot Anatomy of the primary stem (1) is protostele, (4) solenostele, (8) eustele ( dicot stem), (9) ataktostele (monocot stem) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 12 / 33
Stem and shoot Anatomy of the primary stem Vascular cylinder: alternative to ring of bundles Sometimes, vascular bundles are so dense that they form almost a cylinder. We may call this vascular cylinder solenostele (#4 on the scheme of steles) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 13 / 33
Stem and shoot Components of shoot Stem and shoot Components of shoot Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 14 / 33
Stem and shoot Components of shoot Components of vegetative shoot system 1 Main and secondary shoots 2 Terminal and axillary (lateral) buds 3 Nodes and internodes 4 Leaves Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 15 / 33
Components of shoot Stem and shoot Components of shoot Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 16 / 33
Stem and shoot Phyllotaxis Stem and shoot Phyllotaxis Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 17 / 33
Stem and shoot Phyllotaxis Arrangement of leaves: phyllotaxis One leaf per node: spiral, or alternate arrangement Two leaves per node: opposite arrangement, they may be: All in same plane Each pair will rotate on 90 > 2 leaves per node: whorled arrangement (each whorl can also rotates) Each type of phyllotaxis has its own angle of divergence Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 18 / 33
Stem and shoot Phyllotaxis Alternate and opposite phyllotaxes Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 19 / 33
Stem and shoot Phyllotaxis Spiral phyllotaxis: Fibonacci rule Multiple types of leaf spiral leaf arrangement mostly follow Fibonacci rule Formulas of leaf arrangements is very similar to Finobacci fractions: 1 2, 1 3, 2 5, 3 8, 5 13, et cetera Numerator is number of spiral circulations, denominator is number of leaves in a series (counted from zero) Denominator gives the number of orthostychy (this is plural) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 20 / 33
Stem and shoot Phyllotaxis Spiral phyllotaxis: how to make a formula Take a branch, find any leaf (it will be leaf #0) Find the second one which is located in the same position (exactly above or exactly below leaf #0) Count how many leaves are in this series (start from 0), this will be a denominator Imagine (or use a real thread) a spiral which go from leaf #0 to the last leaf of series, count how many times this spiral circulate the stem this is a numerator Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 21 / 33
Stem and shoot Phyllotaxis Spiral phyllotaxis: orthostychy Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 22 / 33
Stem and shoot Phyllotaxis Spiral phyllotaxis: angles of divergence for 1/3 Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 23 / 33
Root Root morphology Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 24 / 33
Root Root system and shoot system Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 25 / 33
Definition and functions Root Root morphology Axial vegetative organ with a function of soil nutrition Other functions: 1 Anchor 2 Synthesis 3 Storage 4 Communication Features: 1 No leaves 2 Geotropic growth 3 Locates in soil or water Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 26 / 33
Types of roots Root Root morphology Primary root: originates from root of seedling Secondary (lateral) roots: originate from primary roots Adventitious roots: originate from stems Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 27 / 33
Primary root Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 28 / 33
Adventitious roots Root Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 29 / 33
Root systems Root Root morphology Tap root system: with well developed primary root (most seed plants) Fibrous root system: without clearly visible primary root (monocots, ferns) Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 30 / 33
Root Fibrous and tap root systems Root morphology Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 31 / 33
Summary Root Root morphology SAM produces protoderm and ground meristem, ground meristem differentiates into cortex and pith Procambium forms vascular bundles or vascular cylinder Outer layers of procambium transform into primary phloem, inner layers into primary xylem Monocot stem usually has dispersed vascular bundles (ataktostele) Spiral arrangement of leaves follows Fibonacci rule Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 32 / 33
For Further Reading Root Root morphology A. Shipunov. Introduction to Botany [Electronic resource]. 2015. Mode of access: http://ashipunov.info/shipunov/school/biol_154 Shipunov (MSU) Introduction to Botany. Lecture 25 November 2, 2015 33 / 33