Development of the Root System Radicle(primary root)(主根)appears at germination Seminal roots(种子根)develop from the seed Radicles (and seminal roots are short-lived Adventitious roots develop from coleoptile 鞘)node Additional roots(不定根)can form at nodes ■RAG日 by Long Ming College of animal science,Northwest Agriculture Forestry University 西北农林科技大学动物科技学院草业科学系
__________________________________________________________________ College of animal science, Northwest Agriculture & Forestry University 西北农林科技大学动物科技学院草业科学系 Copyright reseved by Long Mingxiu Development of the Root System • Radicle (primary root) （主根）appears at germination • Seminal roots（种子根） develop from the seed • Radicles（胚根） and seminal roots are shortlived • Adventitious roots develop from coleoptile（胚芽 鞘） node • Additional roots（不定根） can form at nodes
Plant Structure and Development Leaves ● Stems -third leaf Roots second leaf first leaf Inflorescence Florets coleoptile Caryopsis(fruit)颖 果 -cotyledonary node roots mesocotyl mesocotylar roots caryopsis transitionary node roots F■▣RAGE primary seminal root Copyright reseved by Long M College of animal science,Northwest Agriculture Forestry University 西北农林科技大学动物科技学院草业科学系
__________________________________________________________________ College of animal science, Northwest Agriculture & Forestry University 西北农林科技大学动物科技学院草业科学系 Copyright reseved by Long Mingxiu Plant Structure and Development • Leaves • Stems • Roots • Inflorescence • Florets • Caryopsis (fruit)颖 果
Leaves Grass species that tiller a lot have more leaves near the soil surface These prolific tillering species tolerate close lamina (leaf blade) grazing Leaves have:sheath,blade, ligules,and auricles (a narrow band The sheath,ligule,and of intercalary meristem) auricle make up the collar region ■RAGE Co College of animal science,Northwest Agriculture Forestry University 西北农林科技大学动物科技学院草业科学系
__________________________________________________________________ College of animal science, Northwest Agriculture & Forestry University 西北农林科技大学动物科技学院草业科学系 Copyright reseved by Long Mingxiu Leaves • Grass species that tiller a lot have more leaves near the soil surface • These prolific tillering species tolerate close grazing • Leaves have: sheath, blade, ligules, and auricles • The sheath, ligule, and auricle make up the collar region
Leaf Sheath surrounds the stem above the node where it is attached叶鞘包茎 Blades are veined,flat and narrow有叶脉平展、窄 Blades are vertically oriented to move out from the sheath Blades can be rolled or folded (vernation)during emergence Blades can move to gain the best angle for photosynthesis Auricles are appendages附属 Ligules are membranes or Ligule hairs)膜状或毛状 Collars are hardened areas ■RAG日 where the sheath and blade Auricle Sheath meet Copyright reseved by Long Mingxiu College of animal science,Northwest Agriculture Forestry University 西北农林科技大学动物科技学院草业科学系
__________________________________________________________________ College of animal science, Northwest Agriculture & Forestry University 西北农林科技大学动物科技学院草业科学系 Copyright reseved by Long Mingxiu • Sheath surrounds the stem above the node where it is attached叶鞘包茎 • Blades are veined, flat and narrow 有叶脉 平展、窄 • Blades are vertically oriented to move out from the sheath • Blades can be rolled or folded (vernation) during emergence • Blades can move to gain the best angle for photosynthesis • Auricles are appendages附属 • Ligules are membranes or hairs膜状或毛状 • Collars are hardened areas where the sheath and blade meet Leaf
Stem Are short at first,then elongate into culms ●5 Short stems keep the shoot apex low and less vulnerable to defoliation When daylight and temperature stimulate transition,the shoot apex becomes reproductive ● A reproductive shoot apex becomes the inflorescence ● Intercalary meristem中间分生组织work to push the inflorescence upward Nodes are solid ■RAE Internodes can be hollow,pithy有髓的，or solid Copyright reseved by Long Mig College of animal science,Northwest Agriculture Forestry University 西北农林科技大学动物科技学院草业科学系
__________________________________________________________________ College of animal science, Northwest Agriculture & Forestry University 西北农林科技大学动物科技学院草业科学系 Copyright reseved by Long Mingxiu • Are short at first, then elongate into culms • Short stems keep the shoot apex low and less vulnerable to defoliation • When daylight and temperature stimulate transition, the shoot apex becomes reproductive • A reproductive shoot apex becomes the inflorescence • Intercalary meristem中间分生组织 work to push the inflorescence upward • Nodes are solid • Internodes can be hollow, pithy有髓的, or solid Stem