Micropropagation of banana

micropropagation - banana - steps involving in micropropagation - surface sterilization - initiation of shoot culture - subculturing - rooting - hardening - advantages - problems

1. MICROPROPAGATION OF BANANA LAVANYA.N B.PHARM

2. MICROPROPAGATION Micropropagation is the rapid vegetative propagation of plants under in vitro conditions of high light intensity, controlled temperature and a defined nutrient medium. A whole plant can be regenerated from a small tissue or plant cells in a suitable culture medium under controlled environment. This is also known as direct differentiation.

3. BANANA Banana is a globally important fruit crop with 97.5 million tones of annual production.In India, banana contributes 37% of the total fruit production. Edible bananas do not produce seeds and are traditionally grown vegetatively through suckers.thus low rate of multiplication limits this this method severely. In recent years, tissue culture propagation of banana through shoot tip as well as floral aspices has been utilized to increase banana production. Sword suckers are preferred commercially and it can be taken as explant

4. MEDIUM USED FOR BANANA MICROPROPAGATION For banana micropropagation , MS-based media are widely adopted. Generally they are supplemented with sucrose as a carbon source at a concentration of 30-40 g/l. Media are poured into a glass bottle where suckers are propagated. Usually auxin and cytokinins are added to the banana growth medium. Mostly semi-solid media are used. As a gelling agent, agar is added to the medium

5. STEPS

6. BANANA – MICROPROPAGATION

7. INITIATION OF SHOOT CULTURE Shoot cultures of banana start conventionally from any plant part that contains a shoot meristem . For rapid multiplication, shoot tips from young suckers of 40-100 cm height are most commonly used as explants. From the selected sucker a cube of tissue of about 1-2 cu. M containing the apical meristem is excised. When virus or bacterial elimination is needed , meristem culture is the preferred option.

8. SURFACE STERILIZATION The suckers for culture is prepared and taken into the lab. They are soaked in Bavistin for 18 hrs in order to remove the fungus and fungal spores In lab they were first washed in running water. Then dipped into detergent water for 1 hr. After that they are washed in tap water Washed suckers are taken to laminar flow chamber and further sterilization is done.

9. CONT…. In chamber the suckers are sterilized using mercuric chloride. First the sucker sterilized using 0.12% of HgCl2 . The sucker put into the bottle containing HgCl2. Shake well for 2 min. After that the sucker is washed in distilled water. This step is repeated for the following timings – 2 min, 3 min, 5 min , 12 min. After the 1 st sterilization a layer of the sucker is removed carefully.

10. CONT….

11. TRANSFER TO GROWTH ROOM Banana shoot tip cultures are incubated at An optimal growth temperature of 28 ± 2 ˚C. In a light cycle of 12-16 with a photosynthetic photon flux of about 60 µE/m²s¹. Air condition will be working all the time to provide needed temperature and also provide clean , dust free environment.

12. SUBCULTURING OF BANANA After 2 weeks the suckers will become greenish in colour . 2 weeks after that multiple shoot will arise from the base of the suckers. The shoots are cut at the base separated and placed in a fresh medium. In each bottle three shoots are inoculated. After a week multiple shoots arise from the inoculated shoot. Again they are separated and placed in a fresh medium

13. cont…. The sub culturing is done until the required amount of plant is needed. The shoots are checked everyday for contamination and the contaminated shoots are transferred to a fresh medium. Meanwhile, a set of well grown healthy shoots are taken for rooting.

14. ROOTING OF BANANA Rooting of banana shoot is done in a bottle containing charcoal medium. For rooting IAA is used as growth regulator. It will take 2 weeks for rooting and fresh roots arise at the base of the shoot.

15. ACCLIMATIZATION OF BANANA plantlets Rooted plantlet are kept in basal medium for certain time. Then they are taken for acclimatization process where they are gradually trained to the in- vivo temperature and light. There are 2 stages in the hardening process: Primary hardening Secondary hardening

16. PRIMARY HARDENING The plantlets are transferred to protrays for primary hardening SECONDARY HARDENING

17. Advantages: Pest and disease free seedlings. Uniform growth and increased yield. No staggered harvesting. Round the year planting posssible as seedlings are made available throughout the year. New varieties can be introduced and multiplied in a short duration. In vitro cultures can be stored for long time through cryopreservation. Micropropagation is most advantageous when it costs less than traditional methods of multiplication

18. PROBLEM OF BANANA PROPAGATION: Banana tissue cultures often suffer from excessive blackening caused by oxidation of polyphenolic compounds released from wounded tissues. These undesirable exudates form a barrier round the tissue, preventing nutrient uptake and hindering growth. Therefore, during the first 4-6 weeks, fresh shoot tips are transferred to new medium every 1-2 weeks. Alternatively, freshly initiated cultures can be kept in complete darkness for one week. Antioxidants such as ascorbic acid or citric acid in concentration ranging from 10-150 mg/l, are added to the growth medium to reduce blackening , or the explants are dipped in antioxidant solution ( cysteine 50mg/l) prior to their transfer to culture medium.

19. THANK YOU