Optimisation of somatic embryogenesis in coconut (Cocos nucifera L.)

Samosir, Y. M. S. (Yohannes Maruli Sahap) (1999). Optimisation of somatic embryogenesis in coconut (Cocos nucifera L.) PhD Thesis, School of Land, Crop and Food Sciences, The University of Queensland.

       
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Author Samosir, Y. M. S. (Yohannes Maruli Sahap)
Thesis Title Optimisation of somatic embryogenesis in coconut (Cocos nucifera L.)
School, Centre or Institute School of Land, Crop and Food Sciences
Institution The University of Queensland
Publication date 1999
Thesis type PhD Thesis
Supervisor Stephen W. Adkins
Ian D. Godwin
Total pages 245
Language eng
Subjects 06 Biological Sciences
Formatted abstract

The world production of coconut (Cocos nucifera L.) is low and has not increased significantly over the last few decades. This is mainly due to the use of unimproved varieties. In addition, coconut production has been suppressed by a number of major insect pests and devastating diseases. A solution to all of these problems is in the breeding of new high yielding varieties with genetic resistance to these pests and diseases. Unfortunately, as for many perennial crops, a coconut breeding program takes a long time to undertake and produce useful new cultivars. In addition such programs are very expensive to run, particularly with coconut which has a low multiplication index, particularly in the assisted pollination system used by most breeding programs.

The slow and expensive traditional breeding programs may be improved by the use of in vitro culture methods for coconut improvement. Such methods may include in vitro techniques for the collection, short term storage of embryos from the field, the culture of embryos for screening of large populations, multiplication of zygotic embryos, and somatic embryogenesis for clonal propagation of new improved varieties. Moreover, the latter method could be used as a vehicle for direct genetic transformation. Despite a long history in many parts of the world of research on coconut micropropagation through somatic embryogenesis very few plantlets have ever been produced and no consistency in the protocols has been reported. Thus, the objectives of the present study were to: a) develop a robust technique for the collection and transport of coconut zygotic embryos, b) establish a basic protocol for the regeneration of plantlets via. somatic embryogenesis from zygotic embryo explants and for their acclimatisation and transfer to soil, c) improve the developed protocol by controlling tissue browning, protecting the tissues from ethylene action and stress by using ethylene inhibitors and polyamines, d) promote the somatic embryo maturation and regeneration by using osmotically active substances and abscisic acid (AbA), e) develop somatic embryogenesis protocol for vegetative tissues based on that successful for zygotic tissues, and f) develop basic genetic engineering protocol of coconut using the particle inflow gun (PIG).

The collection and transportation technique developed made use of a low temperature (ca. 5°C) treatment and was able to maintain the viability of the embryos for up to 4 days. During this time the growth of microorganisms was kept to a minimum and therefore contamination of the embryos upon culture was low (≤ 5%). The technique developed did cause some chilling stress to the embryos, as indicated by the significant increases in pH and electrical conductivity of the medium that bathed the embryos, but this did not upset latter plantlet growth. The technique was shown to be useful when it was used to collect several thousand zygotic embryos of Batu Layar Tall from West Lombok, Indonesia. ……………………………………………

Keyword Coconut palm -- Somatic embryogenesis

Document type: Thesis
Collection: UQ Theses (RHD) - UQ staff and students only
 
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