Plant functional genomics study in cassava (Manihot
esculenta Crantz.) to improve starch
quality and quantity for industrial applications.
| Biochemical and molecular genetics related to latex yield and stress response of rubber tree (
Environmental friendly-plant molecular farming.
Epigenetic control: Implications for plant
characterization and functional analysis of starch metabolism
towards improving starch quality and quantity of cassava ( Manihot
2. Research of
molecular markers of stress and of candidate genes for rubber yield
and tree improvement of rubber tree ( Hevea brasiliensis L.).
transformation system for gene function study and generating the
marker free transgenic model and economically important plants.
Cassava's competitiveness as a source for starch may be enhanced
through the genetic improvement of both tuber yield and the
physicochemical properties of cassava starch; the latter being a
function of the lengths and relative proportions of amylose and
amylopectin polymers, the principle constituents of starch granules.
A better understanding of the key metabolic pathways involved in
cassava starch biosynthesis should greatly assist in this regard.
The long-term objective of our research is to facilitate cassava
cultivar development in three main areas: (1) starch yields, (2)
starch amylose/amylopectin ratio, and (3) starch granule morphology.
Towards this end, we propose to isolate and characterize cassava
homologs of genes implicated in various processes affecting the
formation and accumulation of starch. These processes include the
conversion of assimilated carbon to sucrose in photosynthetic
leaves, the transport of sucrose to storage organs via the phloem,
the transition of sucrose to starch, and the subsequent degradation
of starch into simple sugars. By incorporating a team of researchers
from various institutions with different expertise, this research
works can cover an extensive area in cassava biotechnology. Starch
biosynthetic process will be approached from different levels:
biochemical and molecular to field studies. By this approach, it is
expected that the outcome of this research project should be
extensive and can provide useful information and applications for
improvement cassava biotechnology in Thailand .
Among many problems related to the development of rubber production,
the relatively low rubber yield per area is the most serious problem
in Thailand . This is both due to plantation of traditional rubber
clones with relatively low yielding potential and poorly-adapted
exploitation techniques, and increasingly to the expansion of two
kinds of bark disease, leading to the reduction or total cessation
of latex flow. “Tapping Panel Dryness” (TPD) is a physiological
inner bark disorder linked to the stress of overexploitation, most
often extending from the tapping cut, downwards to the bottom part
of the trunk. This disease becomes more and more serious with the
increasing age of the plantations. “Trunk Phloem Necrosis” (TPN), is
an irreversible bark disease of complex origin, with inner soft bark
tissues necrosis. The TPN disease is favored by adverse
environmental conditions (soil and climate), especially in marginal
areas (such in North-East of Thailand ), by anthropogenic stresses
(methods of planting and exploitation), and probably by some
physiological rootstock-scion incompatibility. At the early stage of
these bark diseases, it is impossible to discriminate between TPD
and TPN, and therefore to give in time the adapted recommendations
to the planters. These bark diseases become more and more important
in plantations, and often seriously affect the rubber yield, as most
of the plants are no longer tapped. It is therefore necessary to set
up biochemical or molecular diagnosis tools, and to select or even
create new rubber clones exhibiting low sensitivity to these