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Types of endosperm

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Different types of Endosperm present in Plant life cycles are beautifully described by Rashmi R. Rehman of Gauhati University

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PRESENTATION ON ‘TYPES OF ENDOSPERM’ GUIDED BY- PRESENTED BY- DR. NAMITA NATH RASHMI H. RAHMAN M.SC 2ND SEM DEPT OF BOTANY ROLL NO 3 GAUHATI UNIVERSITY
Types of endosperm
INTRODUCTION Endosperm is a nutritive tissue stored in the seed for the embryo and it is formed by the fusion of one male gamete with the polar nuclei. -Endosperm plays a main role in the diet of human beings. -Endosperm is found in all angiosperms except few families like Orchidaceae,Podostemonaceae and Trapaceae. -The seeds without endosperm: Non- endospermous seeds or exalbuminous seed. -The seed containing the endosperm: Endospermous or albuminous seed.
EXAMPLES OF ALBUMINOUS AND EXALBUMINOUS SEED: Castor Pea
TYPES OF ENDOSPERM -Endosperm is classified into 3 types by Schnarf(1929) on the basis of their mode of development: 1.Nuclear endosperm 2.Cellular endosperm 3.Helobial endosperm Fig: A-Nuclear ,B-Helobial C- Cellular endosperm
NUCLEAR ENDOSPERM In this type of endosperm, the division of the primary endosperm nucleus and its further divisions are not followed by wall formation. Examples. Limnanthes, Oxyspora Fig: Neuclear endosperm in Limnanthes  In some plants, the nuclear endosperm becomes cellular at a later stage.
 Ex. Acalypha, Phaseolus. Fig: A-E; stages in the development of Neuclear type of endosperm CELLULARIZATION OF NUCLEAR ENDOSPERM  The cellularization of nuclear endosperm shows variations.  In Acalypha,the endosperm becomes cellular completely. In Grevillea, the endosperm is cellular in the micropylar region and nuclear in the chalazal
end. The nuclear chalazal end develops into a vermiform appendix (Kausik,1941 Fig: Endosperm formation in Acalypha  In coconut,the endosperm is nuclear type. Later on it becomes cellular.The PEN undergoes several free nuclear divisions.  The endosperm in coconut is partly solid and partly liquid.
Fig: Endosperm formation in Cocos nucifera CELLULAR ENDOSPERM  The division of the PEN and its further divisions are followed by immediate wall formation and the free nuclear stage is completely absent.  It is common in dicots.  Haustoria are common.
Fig: Development of cellular endosperm in Drimys winteri Haustoria in Cellular Endosperm The haustoria may arise at the micropylar end or at the chalazal end or both. In Impatiens , micropylar haustorium is produced. In Nemophila both micropylar and chalazal haustoria are found.
Fig: Endosperm in Nemophila Fig: Micropylar haustorium in Impatiens
HELOBIAL ENDOSPERM It is intermediate in structure. Development is intermediate between nuclear and cellular types. It is more common in monocots. Davis(1966) reported the presence of helobial endosperm in 14 monocot families Fig: Development of helobial type of endosperm in Eremurus
Types of endosperm
RUMINATE ENDOSPERM Endosperm having irregular ridges and furrows on the surface. E.g Areca catechu, Myristica Fig: Ruminate endosperm in Myristica
REFERENCE: 1. THE EMBRYOLOGY OF ANGIOSPERMS, 5TH EDITION, S S BHOJWANI & S P BHATNAGAR 2. DEVELOPMENTAL BOTANY AND EXPERIMENTAL EMBRYOLOGY, ANNIE KUMMARESAN 3. www.publishyourarticles.net
Types of endosperm

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Types of endosperm

  • 1. PRESENTATION ON ‘TYPES OF ENDOSPERM’ GUIDED BY- PRESENTED BY- DR. NAMITA NATH RASHMI H. RAHMAN M.SC 2ND SEM DEPT OF BOTANY ROLL NO 3 GAUHATI UNIVERSITY
  • 3. INTRODUCTION Endosperm is a nutritive tissue stored in the seed for the embryo and it is formed by the fusion of one male gamete with the polar nuclei. -Endosperm plays a main role in the diet of human beings. -Endosperm is found in all angiosperms except few families like Orchidaceae,Podostemonaceae and Trapaceae. -The seeds without endosperm: Non- endospermous seeds or exalbuminous seed. -The seed containing the endosperm: Endospermous or albuminous seed.
  • 4. EXAMPLES OF ALBUMINOUS AND EXALBUMINOUS SEED: Castor Pea
  • 5. TYPES OF ENDOSPERM -Endosperm is classified into 3 types by Schnarf(1929) on the basis of their mode of development: 1.Nuclear endosperm 2.Cellular endosperm 3.Helobial endosperm Fig: A-Nuclear ,B-Helobial C- Cellular endosperm
  • 6. NUCLEAR ENDOSPERM In this type of endosperm, the division of the primary endosperm nucleus and its further divisions are not followed by wall formation. Examples. Limnanthes, Oxyspora Fig: Neuclear endosperm in Limnanthes  In some plants, the nuclear endosperm becomes cellular at a later stage.
  • 7.  Ex. Acalypha, Phaseolus. Fig: A-E; stages in the development of Neuclear type of endosperm CELLULARIZATION OF NUCLEAR ENDOSPERM  The cellularization of nuclear endosperm shows variations.  In Acalypha,the endosperm becomes cellular completely. In Grevillea, the endosperm is cellular in the micropylar region and nuclear in the chalazal
  • 8. end. The nuclear chalazal end develops into a vermiform appendix (Kausik,1941 Fig: Endosperm formation in Acalypha  In coconut,the endosperm is nuclear type. Later on it becomes cellular.The PEN undergoes several free nuclear divisions.  The endosperm in coconut is partly solid and partly liquid.
  • 9. Fig: Endosperm formation in Cocos nucifera CELLULAR ENDOSPERM  The division of the PEN and its further divisions are followed by immediate wall formation and the free nuclear stage is completely absent.  It is common in dicots.  Haustoria are common.
  • 10. Fig: Development of cellular endosperm in Drimys winteri Haustoria in Cellular Endosperm The haustoria may arise at the micropylar end or at the chalazal end or both. In Impatiens , micropylar haustorium is produced. In Nemophila both micropylar and chalazal haustoria are found.
  • 11. Fig: Endosperm in Nemophila Fig: Micropylar haustorium in Impatiens
  • 12. HELOBIAL ENDOSPERM It is intermediate in structure. Development is intermediate between nuclear and cellular types. It is more common in monocots. Davis(1966) reported the presence of helobial endosperm in 14 monocot families Fig: Development of helobial type of endosperm in Eremurus
  • 14. RUMINATE ENDOSPERM Endosperm having irregular ridges and furrows on the surface. E.g Areca catechu, Myristica Fig: Ruminate endosperm in Myristica
  • 15. REFERENCE: 1. THE EMBRYOLOGY OF ANGIOSPERMS, 5TH EDITION, S S BHOJWANI & S P BHATNAGAR 2. DEVELOPMENTAL BOTANY AND EXPERIMENTAL EMBRYOLOGY, ANNIE KUMMARESAN 3. www.publishyourarticles.net