Morphology anatomy and reproduction in Gnetum

Gnetum morphology ,anatomy and reproduction.

Details studies of gnetum

1. Davanagere University Department of Botany Seminar Topic: Morphology, anatomy and reproduction of Gnetum Presented by : S K SACHIN 1 st year Msc 1 st semester Under the Guidance Dr.MANASA D.J Assistant Professor Department of Botany Davangere University

2. Content: Introduction Morphology and anatomy of root Morphology and anatomy of stem Morphology and anatomy of leaf Reproduction in Gnetum Male reproductive structure Female reproductive structure Economic importance conclusion Reference

3. Introduction: Gnetum is plant are similar to the dicot plant. Distribution of Gnetum in 40 to 50 species in world. Habit : woodyclimbers , some shrub’s or tree The Gnetum sporophytic body is differentiated into Root ,Stem, Leaves . In the gentum 2 types branches like as 1) Branches limited growth . 2) Branches unlimited growth Leaves are simple , decussate ,Broad (large) , evergreen , ovule with entire margins . Leaves arranged decussate fashion with reticulate venation. Retulate venation: the arrangement of veins leaf where they from weblike structure

4. Decussate : opposite leaves arranged with each succeeding pair at right angles to the pairs below and above them. 5 species of Gnetum are found in India mainly distribution tropical regions. Like as : 1) Gnetum gnemon : small tree or shrub with small branches. Assam , Manipur,Arunachal Pradeshl . >2) Gnetum montanum : woody climbers . occur Assam , Manipur ,Sikkim . > 3) Gnetum latifolium : Evergreen shrub or climber species is mainly distributed in Andaman and Nicobar islands. > 4) Gnetum contractum : it is shrub occurs in Kerala . > 5)Gnetum ula : woody climbers , swollen nodes the occurs in eastern and western ghats .

5. Gnetum gnemon Gnetum latifolium Gnetum ula Gnetum montanum

6. Morphology and anatomy of Root : Morphology of root: > The usely taproot branches . Secondary advantious roots are present. Anatomy of root : Epidermis single layered root hair present. Cortex : many layered perenchymatous with starch grains few fibre cells are present. Endodermis and pericycle are in many layered. Metaxylum towards centre and protoxylum towards periphery .

7. Secondray growth is present in Gnetum root . Roots are diarch and exarch condition in the vascular bundles. Exarch : arrangement of xylem tissue in which protoxylem towards the periphery and metaxylem towards the centre . Diarch : Diarch condition 2 vascular bundles or xylem present in dicot root .

8. Morphology and anatomy of Stem : Morphology of Stem : Gnetum stem is elongated and dicot . Stem is node and internode are present. 2 types of shoot like as: . 1) short shoot : limited growth . 2) Long shoot: unlimited growth. Anatomy of stem : The Cuticle is thick covered with epidermal unicellar layer. Sunken stomata are present. The Cortex is elongated with many layer like chlorenchymatous ,parenchymatous and schlerenchymatous cells .

9. Endodermis and pericycle indistingiushable . Vascular bundle is separated by parenchymatous cells with one another. The vascular bundles are conjoint . The cambium in present and separated by vascular bundles to the xylem and phloem . Xylem consists of xylem vessels, tracheid. Phloem consists of sieve tube and phloem parenchyma. In the pith contains parenchymatous and laticiferous cells present.

10. Morphology and anatomy of leaf: Morphology of leaf : Leaves are simple broad (large) . Leaves ovule and entire margins. Leaves are decussate fashion and reticulate venation. Decussate : leaves arranged opposite to each other. Anatomy of leaf : Leaves similar to dicot . Cuticle covering with epidermis . Stomata are present. Palisade mesophyll and spongy mesophyll are present and it’s contains chloroplast .

11. vascular bundle are present and curve or (Arc) form in the midrib region. Vascular bundle are conjoint . In the vascular bundle xylem and phloem is present. In the xylem consists of tracheid , vessels xylem parenchyma. In the phloem consists sieve cell and phloem parenchyma are present Middle portion cambium is present.

12. Reproduction in Gnetum: Gnetum is dioecious and cones / strobili reproductive stature . The Gnetum strobili/ cones organised into inflorescence or panicle and terminal position. The cone axis are node and internode present. Whorl of circular bracts are present at node. Flower present these collars upper few collars may be reduced and sterile in nature . cupule Are present in the nodal region.

13. Male reproductive structure: Male reproductive organs Gnetum is male cone/ strobili. Male cone / strobili show the node and internode . Each node more number of whorl like structure present called male flower . Male flower at the part abortive ovule present Gnetum of male reproductive system. Above these abortive ovule male flower are arranged in a whorl like stature . All male flower protected by cover or coat or cup like like structure called cupule .

14. In this cupule is transparent layer protected to male reproductive organs young age to adult age . In male reproductive organs above the perianth dithicous anthers present.

15. Female reproductive structure : Female reproductive organs Gnetum called female strobili /cone . Female strobili devloped female plant in terminal part of the shoot. In the female cones are present in node and internode present Each node more number of ovule devloped in whoral like stature. These ovule are protected by coat or cup like stature called cupule . Below the cupule more number of ovules present and developed these ovule called as female flowers. **********************

16. Structure OF OVULE: The ovule represent female flower. The ovule stalk in some Gnetum species , sessile or subsessile . In that ovule massive nucellur tissue made up . The ovule protected by 3 envelopes or integument as outer ,inner, middle envelopes. > Inner envelop or integument elongated to form long micropylar tube Inner integuments free from nucellus except to chalazal end All 3 envelop .of ovule develop in acropetal manner. In the pollen chamber is present at tip of nucellus .

17. Economic importance of Gnetum: Young leaves and inflorescence of Gnetum gnemon and Gnetum latifolium are cooking vegetable . Seed of Gnetum gnemon , Gnetum latifolium , and Gnetum ula eaten after . Boiling sometimes they are fried in oil and eaten. G.gnemon , G.latifolium used to ropes prepared from this fiber are light strong . G.montanum Possesses pesticidal properties.

18. Conclusion Gnetum plants are gymnosperms they produce seed but not enclosed in a fruit. They typically have broad leaves and found in tropical region. They evergreen plant and small shrub ,tree and some climbers . The sporophytic plant is easily differentiated into Root , stem, leaves. The Gnetum stem ,leaf is resembles to dicot type .

19. Reference 1. B.P. PANDEY, College Botany, S.Chand publication,1979 . Pg no: 121- 161 2. A.V.S.S.SAMBAMURTY ,A Text book of Bryophytes , pteridophytes , Gymnosperm and paleobotany , I .K International publication, 2005 . Pg no: 396-418. . ***********************

20. Thank you