Tissue culture: Tissue culture is growth of tissues or cells separated from organisms. It is done to produce clone of mother plants by facilitating with all required nutrients within culturing media, which could be either liquid, semi-solid or solid. The part of healthy and disease free plant which is used for tissue culturing such as cell, leave or root is called explant.
The media used, for this biological technique of tissue culturing, is synthetic which contain all essential nutrients and hormones required for plant growth. The prepared media is loaded in flask or petri dishes to grow the ex-plant. Explant is inoculated in medium and set on incubation at proper temperature and environmental conditions which are required for growth. Contamination in explant or media can’t be compromised. To meet up the requirements of procedure media is prepared in controlled contamination free conditions and explant is sterilized to kill all microbial contaminations. Number of plants can also be increased by following the process of sub-culturing. It is basically transferring of shoots in new media culture dishes. Firstly, ex plant are grown in shoot promoting medium after that into root promoting medium.
The plants which are produced through the tissue culture technique are decontaminated and free from all micro-organisms. Tissue culture technique is used for the production of various virus free plants for the purpose of enhancing the production. Due to attack of different viruses on crops every year production reduces and ultimately economic losses occurred. Different types of chemicals are used to control the virus attack but such parameters show harmful impact on plants and human health. So here we use tissue culture technique which don’t show harmful effects and also helpful to increase the production of virus free crops.
Garlic Case Study:
Every year the production of garlic is reduced due to attack of different viruses. For example in Turkey the production of garlic was 105-363 tons from two clones of garlic Allium sativum and Allium tuncelianum. Due to attack of common virus, Onion Yellow Dwarf Virus (OYDV) and leek yellow stripe virus (LYSV) the production of garlic is reduced from 30-100 percent. Different chemicals are used but there is no effective result. Meristem tissue culturing of garlic shoot tip is done to control the production losses. In case of garlic, tissue culture technique of two ex-plant samples of two different species is done and the provided media is also different for both explants. The effect checked by real time PCR.
To ensure the better growth of plants, all contaminants were removed by surface sterilization A.sativum and A. tuncelianum were propagated and after propagation shoot tips were extracted and placed in MS media (germination media).
90 meristem and 90 shot tips were used in experiment. Both specie shows better result in media 2. 85/90 meristem And 84/90 shot tips grow in case of A.tunceliaum and 89/90 meristem 87/90 shot tips in case of A.sativum. At the end DNA were extracted from both species to check the virulence rate. Real Time PCR were used for this purpose. Result shows the plants which produced by this technique was virus free.
Iqra Khalid1, Asad Riaz 2, Aqsa Tahir3, Farah Kanwal4
Center of Agricultural Biochemistry and Biotechnology,
University of Agriculture, Faisalabad.