Bamboo propagation technique takes root

News India/March 2003

Bamboo is the backbone  of the rural economy in many South-east Asian countries, but the loss of its habitat has increasingly affected its cultivation.  Fortunately a group of researches in the state of Himachal Pradesh have developed an efficient method for the rapid propagation of bamboo.

The fast growth and short life cycle of bamboos have made them an important part of forestry programmes. One such species is Dendrocalamus hamiltonii, which is popular because it is tall and fast growing, and its strong culms can provide structural support in buildings, In additions, its leaves make an excellent cattle fodder.

But as its habitat is reduced, propagation techniques are becoming ever more important. The traditional ‘offset’ method is slow, cumbersome and highly labour intensive.  Tissue-culture techniques, which allow the formation of multiple shoots, provide a partial answer to this problem, but previous studies have shown that the rooting of these shoots is inconsistent, which only a 25-30% success rate1.

This is where the technique of ‘somatic embyrogenesis’- modified here by Anil Soon and colleagues Madhu Sharma, P.S. Ahuja, Savita Godbole and Rajesh Thakur at the Institute of Himalayan Bioresource Technologyin Palampur-comes in.

In this method, a callus raised from nodal buds of mature bamboo plants is chemically induced to develop embryos.  After 8 weeks these are germinated and produce plantlets during the next three weeks.  The success rate of this technique is 80% the researchers report.

To demonstrate the method, the team used new sprouts from the nodal segments from 8-10-year-old field-selected elite bamboos to obtain the callus.  

Embryogenes is was induced in the callus and individual embryos were separated and transferred to a nutritive medium from germination.  Up to 78% of the resulting plantlets survived in soil under greenhouse conditions, and after six months the rooted plants were ready for transplantation to fields, where they performed better than normal nursery-raised plants.

According to Sood, the technology involved three critical steps: arresting the division of the embryogenic tissue, maturing the somatic, embryos, and germination.  This was achieved by using a different medium at each step, such as a concentrated sucrose solution, which enhances the conversion of embryos into plantlets under low light conditions.

Somatic embryogenes is in bamboo was first reported some 20 years ago for another species, Bambusa arundinacea, using seeds at the starting material.  In contrast, the Palampur team demonstrated their technique using the callus of the most popular bamboo species, D. hamiltonii.  They have also found the best combination of plant growth regulators to induce a callus to differentiate only into embryos, where are important for obtaining plantlets and achieving faster rates of multiplication.

Sood says, that once the plantlets are formed, these could again be sub cultured to obtain rhizomes, from which segments could be used for further multiplication of the bamboo.

1. Sood A., Ahuja, P.S. Sharma, M. Sharma, O.P. & Godbole, S. Plant Cell, Tissue and Organ Culture 71,55-63 (2002).
2. Godbole, S. Sood, A., Thakur, R., Sharma, M. & Ahuja, P.S. Current Science 83,885-889 (2002)