Acclimatization of plantlets

ppt on Acclimatization of plant lets by sajal sir

1. Acclimatization of Plantlets March 11, 2016 Department of Biotechnology, PRSU, Raipur By: Sajal Shrivastav M.Sc II Semester Guided by: Dr. Afaque Qureshi 1

2. Introduction Transplantation and Acclimatization Difference in growth conditions : in vitro & ex vitro Deficiencies of in-vitro grown plants Morphological Deficiencies Anatomical Deficiencies Physiological Deficiencies Steps in Acclimatization In-vitro Acclimatization Significance of Acclimatization Conclusion Reference Synopsis 2

3. The ultimate purpose of plant tissue culture technology will not be achieved if plantlets grown in vitro do not survive in harsh and uncontrolled environment of the field. This technique of transferring the lab grown plantlets into field is TRANSPLANTATION or Stage IV. Transplantation is the crucial and utmost care appealing stage. Acclimatization is the principle that governs Transplantation. INTRODUCTION 3

4. Definition “Acclimatization is the phenomenon whereby plants morphologically, physiologically and anatomically adjusts from in-vitro to ex-vitro environmental growth conditions.” “It is the process during which plants become adapted and gets accustomed to a new culture and environmental ambience .” Acclimatization is also known as hardening off . 4

5. Etymology of acclimatization : Root word is climate. Derived from ancient greek word “ klima ” means “ inclination ” or “slope”. Ac + climate+ ization . Acclimatization word is also used for other living systems. Eg . Acclimatization at high altitudes Acclimatization after heibernation . 5

6. Transplantation & Acclimatization It’s a technique/step in PTC. Its inbuild ability of plants to adapt/respond to changed environment. 6

7. Difference of growth conditions : In-vitro & ex-vitro In-vitro High conc. Of organic and inorganic nutrients. Presence of Growth Regulators High Relative Humidity. Low Light Intensity. Low Temperature. Poor gaseous exchange. Utmost physical care is taken. Ex-vitro Photoautotrophic nutrition allowed only. No growth regulators. Low relative humidity. High light intensity. High Temperature Gaseous Exchange must be done. Chances of physical tragedy like wind flow, water currents etc. 7

8. Deficiencies in in-vitro grown plants Deficiencies are due to the fact that in-vitro regeneration focuses only at providing the optimal growth conditions required for the explant to grow rapidly. There are three types of deficiencies observed : Morphological Deficiencies Physiological Deficiencies Anatomical Deficiencies 8

9. Morphological Deficiencies Shoot Reduced length Reduced number Reduced dry mass Root Reduced length No root hairs Reduced dry mass Leaves Reduced blade expansion Reduced number Reduced length Reduced internodal length 9

10. Anatomical deficiencies No/Reduced formation of cuticle and epicuticular wax. Thinner epidermal layer Thin Cell wall Reduced Sclerenchyma/Collenchyma formation 10

11. Poor Anatomical differentiation in leaves Stomata - Greater stomatal frequency Impaired stomatal growth Light/dark insensitive stomata Mesophyll – Poor differentiation Palisade is poorly developed Loosely organized Spongy mesophyll (large intercellular spaces.) Weak Vasculature in leaves Chloroplast – poorly developed Low chlorophyll contents Disorganised grana 11

12. Physiological deficiencies Low light High Humidity Less CO2 High Sucrose HETEROTROPHIC NUTRITION NO photosynthesis Less Chlorophyll Inactive / No photosynthetic enzymes 12

13. Steps in Acclimatization Transfer plantlet from in-vitro culture tubes. Wash its roots to remove agar Primary Hardening – Potting mixture- contains no organic nutrition but low inorganic nutrition . Eg : Peat, Perlite, polystyrene beads, vermiculite, fine bark, coarse sand etc or their mixtures in different proportions are used. External N, P, K and urea are also applied. High Humidity (90-100%) and low light is provided in a misting/fogging chamber for for 10-15 days. 13

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15. Methods to provide high to low humidity : Cover plants with transparent plastic bags with small holes in it and increase decrease the humidity gradually by enlarging those holes. Culture vial cap is loosened day by day (7-10 days) to create humidity gradient. Last the vial is kept uncapped. Then transplanted in potting mix. 15

16. Misting and Fogging systems : Sophisticated chambers providing Humidity gradient using saturated air. Misting is cheaper but less efficient as causes nutrition to leach and making plants dry. Fogging is expensive but has no such problems as misting. Produces water droplets less than 20µm . Image- Misting tunnel (droplet size more) Image- Fogging chamber (droplet size very less) 16

17. Tropical countries uses this technique to create Humidity Gradient: One side has wet curtains of cellulose or polystyrene pads which are constantly supplied with water on other side exaust fans. This creates a Humidity gradient along with Temperature gradient (5-6 ˚C reduction) 17

18. After that 4-6 weeks plantlets are transferred from High Humidity-low light zone (of misting/fogging chamber) to Low humidity-High light zone(Green house or nethouse ). Image – a green house Image – a net house 18

19. Use of Anti- transpirant to reduce water loss during transpiration : Leaf-surface covering agents such as glycerol, paraffin and grease promoted ex-vitro survival of several herbaceous species ( Selvapandiyan et al.) S tomatal transpiration of micro-propagated cauliflower plantlets were reduced with a leaf spray of 10mM ABA ( Wardle et al .) 19

20. In-vitro acclimatization Why its done? Ex-vitro acclimatization is labour intensive High capital required How its done? Infecting in-vitro plantlets with Rhizobium. Using culture vials with microporous lids. Use of dessicants on culture vials. Use of certain growth retardants ( anti gibberellins ) shows more survivality in ex-vitro as reported. Induction of storage organ formation by manipulating sugar/PGR contents. Image- Paclobutrazol effect on transplantation Image- Micro- porous culture vials. 20

21. Significance of Acclimatization Allows plants to regain its actual tolerant capacity. Necessary for higher survival rates of in-vitro plantlets. In-vitro acclimatization can help reduce the time requiring criteria of ex-vitro hardening. 21

22. Conclusion 22

23. References Plant Tissue Culture Theory and Practice, S S Bhojwani and M K Razdan . https :// www.academia.edu/2514456/Acclimatization_of_tissue_cultured_plantlets_from_laboratory_to_land http :// www.iisc.ernet.in/currsci/dec252003/1704.pdf http :// www.isaet.org/images/extraimages/P315405.pdf http :// digitool.library.mcgill.ca/webclient/StreamGate?folder_id=0&dvs=1457636214994~299 http ://www.scielo.br/img/revistas/babt/v57n5// 1516-8913-babt-57-05-00636-gf01.jpg 23

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