Development of an embryo culture manual and an embryo transplantation technique for coconut germplasm movement and seedling production of elite coconut types

• Philippine Coconut Authority, Philippines

World coconut (Cocos nucifera L.) productivity has been low for decades and nearly two-thirds of the existing palms are now too old for sustained production. Coconut farmers, mostly low-income smallholders, in more than 90 countries need high-yielding varieties which suit their local conditions. A systematic replanting program requires a good breeding program that relies on the availability of new germplasm. But the collection and movement of coconut germplasm must be undertaken using embryo culture techniques because transporting the whole fruit is impractical and also unsafe from a phytosanitary perspective.
An earlier ACIAR-funded project (HORT/1998/061) developed a new protocol of embryo culture. The new protocol is more efficient for producing robust plantlets that give a high percentage of plant establishment. The details of this embryo culture protocol need to be shared with other potential users beyond the present team, creating the need for a manual. This project developed a manuscript describing the protocol in English, Indonesian and Vietnamese, for publication and distribution as a manual through ACIAR.
The second part of the project sought to develop a reliable embryo transplantation technique as an alternative step to that of embryo culture, which is often tedious and expensive to undertake. Pioneering research undertaken during the earlier ACIAR-funded project showed that isolated embryos could be inserted into surrogate nuts and then nurtured to produce healthy seedlings, but the success rate of production was low. Studies were thus undertaken to improve this technique, using fresh locally grown coconuts in the Philippines.

The information generated from the previous ACIAR project was collected and collated to produce the new embryo culture manual manuscript. This manual manuscript then underwent a series of editing steps to accommodate the views from the partners involved in the original project. The final edited version of the manual manuscript is now available for publishing by ACIAR in English, Indonesian and Vietnamese. The manual will find use in many laboratories including those of the Coconut Genetic Network (COGENT) International Coconut Gene banks which are located in the five main coconut-producing regions of the world.
The second part of the present project concerned the improvement of an embryo transplantation technique for the rapid production of seedlings of the high value coconut types. This part of the project took place at the Albay Research Center (ARC) of the Philippines Coconut Authority (PCA) and also involved the provision of some laboratory equipment and staff training at the University of Queensland.
A number of experiments were undertaken at ARC in attempt to improve the previously developed embryo transplantation technique. However, as yet no improvements have resulted in the germination of any of the transplanted nuts. This may relate to the fact that only poor quality fruit were available to do this work. Fruit quality had been significantly reduced by a series of severe typhoons hitting the region during the course of this work. Work is now under way to improve the technique using higher quality fruit.
The main impacts of the project have been for the Filipino project partner (ARC). The capacity of their centre to undertake coconut research has increased, enabling the present work to continue on, with some small amount of national support after the present project finished. There is now an opportunity for the centre to take the outcomes of the project, particularly those to do with embryo culture, to the next stage of development and maybe commercialisation.
A pilot study is now needed to scale-up the approach, particularly to cater for the high-value coconuts such as the aromatic types Kopyor and Makapuno. At the same time the capacity of the partner country would be significantly improved if a genetic pool of these types of coconut could be established there. The centre could then exhibit to private investors and coconut farmers the commercial potential of the technique. This pilot project would increase the likelihood of the present project (and other previously ACIAR-funded projects) having a higher impact and for that impact to be realised more quickly.