Automation in Plant Tissue Culture
Authors: J. Srinivasan, J. Vanitha and R. Mahendran

The plant tissue culture or micropropagation is a method of propagating disease-free clonal plants. Plant tissue culture is favoured over propagation by conventional means such as by cuttings or seeds as it offers various advantages. Usually micropropagation can be achieved in three different ways: (i) by direct organogenesis via shoot tip or axillary buds, (ii) by indirect organogenesis through callus and (iii) by somatic embryogenesis directly or indirectly.

Commercial exploitation of tissue culture technology is limited to only a few species because of the high cost of production. Labour and media constitute more than half the cost of a tissue culture operation. This can be reduced substantially by devising systems that use liquid media. Bioreactor technology can be used to produce somatic embryos en masse. Automated systems are also available that can be used for micropropagation through axillary buds. Plant tissue culture techniques, however, were developed initially to understand the nutritional and morphological aspects of plant development. With improvement in media and other manipulative techniques, it has amplified its scope and now plants are micropropagated at commercial level. It has already become a multi-billion-dollar industry producing vast numbers of plants.

The equipment or hand tools for manipulating and transferring tissues were developed. Such a system has been developed for the transplanting of interior spruce somatic seedlings to ex vitro conditions. With the progressive development of more efficient and cheaper automated systems, cost effectiveness of the systems will improve and the cost of plantlets somatic seedlings will be reduced.

ROBOTICS

Robotics in micropropagation can be of use on micropropagation for example in media preparation, cutting microshoots and placing them back on fresh medium (Miwa et al.,1995), For encapsulation of somatic embryos (Sakamoto et al., 1995).

The first commercial automated tissue culture robot (the Vitron/sup TM/ 501) was introduced by the Australian company ForBio Robotics in 1997. Their target species included eucalypts, acacia, teak and pine. Osmotek in Israel has introduced manual and mechanical separators on the market, they clearly make cutting microshoots more efficient.

Miwa (1991) has described a fully-automated robotic multiplication system for chrysanthemums. With this system, the robot hand dealt with both cutting and transplanting operations. In this system, presence or absence of an axillary bud on a stem cutting judged by image analysis. There are two publications in Japanese describing various robots for automation in tissue-cultured plantlets (Miwa et al., 1988) and for transplanting of lily bulblets (Yamasita et al., 1991).

Types

Total automation

With the use of image analysis system and a robot or other device – dividing, separating, moving of planting tissues, shoots, somatic embryos or plantlets. Little/no human intervention, except to control the computer and repair parts. Eg- Toshiba plant tissue culture robot (Fujita & Kinase, 1991)

Semi automation

The involvement of human operators contributing to any stage of the process. Most likely involving the decision-making. This is the most commonly researched type of automation and the level at which we are most likely to effectively capture the benefits of human intelligence and expertise together with the latest technological advancements in engineering.

Advantages

Automation is not only a matter of economy. There are many advantages which may be generated by automation.

1. Management — It is very clear that the management of a machine will be much easier than management of a large group of people. The management administration and overhead would also be reduced substantially.

2, Contamination - There is always much more contamination associated with people than with equipment. Therefore, reduction of contamination can be expected by using automation.

3. Cast in the future - It is also clear that the cost ofa robotic machine will be cheaper in the future due to rapid development of electronic and machinery technology. On the other hand, labor cost is going to be increased annually.

4. Operation time — It is a challenge for a facility to operate two shifts or more per day. This is especially true if the operation involves more than a hundred people, however, the number of persons required to operate several machines is going to be very limited. Therefore, two or even three shifts will become possible. This will greatly increase the utilization ofcapacity and reduce the depreciation costs per unit.

5. Uniformity — Machines act uniformly. If machines. through more sophisticated applications of machine vision or other sensor, can improve discrimination between standard product and oft‘-type product, it shouldproduce a more uniform product at the end. The variation between people and their emotional differences from day to day are always one of the major factors effecting product uniformity.

Disadvantages

1. Correction ability — Plants are living materials. They are all different and no two plants arc exactly the same. Contamination and off type can happen anytime. Early detection is the best way to prevent commercial damage. Application of automation will naturally decrease the opportunity to detect contamination and off type at an early stage to prevent them from being propagated.

2. Flexibility — Plant growth and shape are affected by uncontrollable environmental factors. It is much easier to request flexibility from people than from machines, especially from lot to lot. or from box to box. Once production is started on non-uniform stock, it would be very difficult to use a machine to correct it.

References :

1. Huang, K.Y., Lin, T.T., 2001. Development of a sorting system for Phalaenopsis seedlings. Journal of Agricultural Machinery 10 (4): 85–98.

2. Huang, Y.J., Lee, F.F., 2008. Classification of Phalaenopsis plantlet parts and identification of suitable grasping point for automatic transplanting using machine vision system. Applied Engineering in Agriculture 24 (1), 89–91.

About Author / Additional Info:
I am working as assistant professor Sethu Bhaskara Agricultural College and Research Institute