Unit 1: Crop Plant Anatomy CROP PRODUCTION Unit 1: Crop Plant Anatomy

The Study of Anatomy… Agronomists use anatomy to: Describe and identify plant species Identify pests Make management decisions and Many other purposes Monocotyledons have 1 seed leaf; also known as grasses Dicotyledons have 2 seed leaves; also known as broadleaf plants

The Plant Cell (p. 2) Cell wall: protect inner parts; give shape to cell Plasma membrane: permeable to some materials Nucleus: contains chromosomes Ribosomes: protein manufacturing Endoplasmic reticulum: protein manufacturing

The Plant Cell (p. 2) Cytoplasm: contain functioning parts of the cell Chloroplasts: site of photosynthesis; green in color Vacuole: storage of wastes; regulates pressure within cell to maintain rigidity

The Plant Cell (p. 2) Mitochondria: anaerobic respiration—main source of energy and metabolic growth Dictyosome: cell wall formation www.cellsalive.com

Seed and Seedling Anatomy Cereal Caryopsis Anatomy: be able to label each part listed below (p. 3-4)— Brush Dent Pericarp Aleurone Layer Endosperm Scutellum Black Layer Coleoptile Epicotyl Apical Meristem Scutellar Node Radicle Coleorhiza Tip

Cereal Seed (p. 5) Germination & seedling establishment Day 0-1: pericarp imbibes water Day 1-2: coleorhiza elongates Day 2-4: radicle breaks and becomes anchored into soil; coleoptile elongates Day 5-7: seminal roots begin development; with radicle they are primary root system

Cereal Seed (p. 5) Day 7-14: mesocotyl elongates; first leaves break through coleoptile; turn green and begin photosynthesis Day 14-21: coronal roots develop just below soil surface; become principle absorbing roots after three weeks; growing point is below soil for 30 days Class Questions: p. 6-7

Seed and Seedling Anatomy Legume seed anatomy: be able to label each part listed below (p. 7-8)— Pod Micropyle Hypocotyl Embryo area Hilum Radicle Epicotyl Testa Cotyledon

Legume Seed (p. 9) Germination & seedling establishment Day 0-2: testa imbibes water; hormones stimulate radicle growth Day 3-4: hypocotyl pulls cotyledons toward soil surface Day 4-6: hypocotyledonary arch straightens as seedling emerges; testa falls off; branch roots develop

Legume Seed (p. 9) Day 6-12: cotyledons unfold; begin photosynthesis until 1st leaves unfold Day 12-18: trifoliate leaves unfold; first root nodules form, containing rhizobium bacteria to fix nitrogen; apical and axillary buds lead to vegetative growth Class Questions: p. 10-11

Plant Leaves (p. 11) Leaf Anatomy Veining—parallel (grasses) and netted-veined (broadleaves)

Plant Leaf Anatomy (Cont’d) Cross section (p. 12) Cuticle Epidermis Mesophyll (palisade and spongy parenchyma layers) Vascular bundle (xylem and phloem) Bundle sheath Stoma Bulliform cells Cross section of corn (Zea mays) leaf; vascular bundle from corn leaf

Plant Leaves Grass Leaf Morphology— identify grass leaf parts (p. 14) Ligules Leaf buds Sheath Midrib Rhizome Auricles Seedhead Node Tiller Collars Spikelet Blade Stolon

Plant Leaves Legume Leaf Morphology—identify legume leaf parts (p. 15) Leaflet Petiole Petiolule Stipule

Plant Stems (p. 16) Functions of stems: Conduct water and minerals Conduct synthesized food Support stem, leaves, and flowers Store food materials Manufacture carbohydrates Asexually propagate new plants

Plant Stems (p. 16) Stem Anatomy—vascular bundle arrangements Dicot—bundles arranged in a ring on the cambium around the pith Stalk—bundles scattered throughout ground parenchyma (corn, sorghum, sugar cane) Culm—bundles scattered in a ring; hollow center (wheat, rye, oats, and barley)

Plant Stems Modified stems (p. 18): Stolons—above soil surface Rhizomes—below soil surface Tubers—enlarged underground stem Haplocorms—enlarged internode at crown

Plant Roots (p. 18-19) Functions of roots: Anchor plant Absorb water and minerals Transport water and minerals to plant stem                

Plant Roots (p. 19) Root anatomy: be able to label each part listed below (p. 19)— Root cap Zone of maturation Xylem Branch root Zone of cell division Mature zone Phloem Root hairs Zone of cell elongation Cortex Epidermis

Plant Roots (p. 20) Root systems: Grasses — Broadleaves — fibrous root system tap root system

Inflorescence (p. 20) Grass and legume inflorescence—reproductive structure of a plant (be able to label all parts listed) Seeds are formed from florets which contain reproductive organs Seeds are economically valuable products Inflorescence knowledge leads to understanding seed yield and plant reproduction

Inflorescence Parts of a grass floret (p. 21): Palea Stamen (filament and anther) Lemma Pistil (stigma, style, and ovary) Awn

Inflorescence Parts of a grass spikelet (p. 21-22): Glume Rachilla Florets Awns

Inflorescence Parts of a legume flower (p. 23-24): Corolla Calyx Stamen (filament and anther) Pistil (stigma, style, and ovary) Female portion = gynoecium

Inflorescence Inflorescence types (p.25-27): Spike – spikelets attached to central stalk of inflorescence (wheat, rye, and barley) Raceme – spikelets attached to stalk (rachis) by smaller stalks called pedicels (alfalfa, sweet clover, and soybeans) Panicle – spikelets pedicels attached to panicle branch, attached to rachis (oats, rice, sorghum, corn tassel) Head – flowers clustered together; attached to enlarged, shortened receptacle (white & red clover and sunflower) Umbel – few flowers attached at same point on salk

Website resources: Chapter 1 www.cellsalive.com http://www.botany.org/plantimages/PlantAnatomy.php http://en.wikipedia.org/wiki/Grass http://www.extension.umn.edu/distribution/cropsystems/components/DC5963b.html http://www.gramene.org/oryza/rice_illustrations.html Chapter 1 Review Questions (p. 28-32) Thinker