Early Growth Stages of the Rare Acridocarpus orientalis in the UAE—A First Step towards Conservation
4
the emergence and the growth rate of these roots is very
fast. The aerial part showed also a rapid growth rate. The
first leaf emerged 1 to 3 weeks after root emergence. The
plants continued to develop its root system even after leaf
emergence.
The biggest problem encountered during this germi-
nation trial is the mortality of germinated and non-ger-
minated seeds. Many seeds died before their germination,
but a considerable number died at the stage of 2, 3 and
even 6 leaves.
Even if the laboratory essay showed a higher rate of
seed germination, no seedlings could survive to the end
of the experiment. However, six plants issued from the
directly sowed seeds in pots in the greenhouse are still
surviving. It may be a problem of acclimation to the
greenhouse environment.
4. Discussion
The results of this study showed that A. orientalis seeds
were not dormant. In fact, 32% of seeds germinated and
all the non-germinated seeds were viable. The higher
percent germination was observed with seeds soaked in
water. This can be explained by the removal of the
viscous layer coating all seeds of A. orientalis, after
being soaked in water. This result confirmed that of re-
ports [18] indicating that all the priming treatments
improved the emergence, seedling growth and reserve
metabolism.
The rate of germinated seed mortality, underline the
need for further future investigations into post germi-
nation conditions and acclimation.
Observations of root growth revealed the ability of this
species to survive in dry regions. It developed long
principal roots with many secondary roots, which high-
light the ability of A. orientalis to extract soil moisture
even in deep substrate levels. The potential water uptake
in any soil layer depends on the soil water content and
the root density, and for whole soil profiles water uptake
depends on the rooting depth and total root length [19].
5. Conclusion
This study provided some much needed information
about the germination conditions and the growth stages
of the rare plants species A. orientalis. However, the lack
of information on its growth requirements is urgently
needed to be addressed, in order to overcome A. orien-
talis rare status in the UAE. Additionally, improved un-
derstanding of the species soil and habitat preferences,
through soil nutrient analysis within its niche in Jabal
Hafeet are also required. Ecological interactions of the
species could offer more information about the growth
conditions of A. orientalis, which will certainly improve
the rate of success to protect it.
6. Acknowledgements
The funding by the Mohamed bin Zayed Species Con-
servation Fund is much appreciated (Fund No. 21S031).
The investigators would also like to express their sincere
appreciation to the Office of Research Support and
Sponsored Projects at the United Arab Emirates Univer-
sity for their support and the management of this project.
The support from the Biology Department and the Fac-
ulty of Science is also much appreciated. Assistance from
all students in any parts of this project is appreciated.
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