Tyre Asia April/May 2018 55
scavenging were up-regulated
in JCs of CATAS 7-33-97 and
Haiken 2, indicating that the JCs
provide sufficient molecular basis
for the increased rubber yield.
Comparative trial between self-
rooting JCs and DCs has proved
self-rooting JCs exhibited better
performance in rubber yield.
Such investigation clearly indicates
the intricateness of stock-scion
interactions. No doubt, such
investigations can gain a perfect
juvenile selection system in Hevea
in the years to come. Scientists at
Chinese Academy of Tropical Crops
at Haikou must be congratulated
for such advancements.
Scientists of RIKEN team of Japan,
working in collaboration with
Universiti Sains Malaysia (USM),
Chinese Academy of Tropical
Agricultural Sciences (CATAS)
are the claimers of draft genome
of Hevea. It is noteworthy that
the CATAS assembly captures
practically all the USM sequences
contained in a purportedly larger
draft genome. It appears that
CATAS has done a better job of
fitting contiguous sequences into
a smaller number of scaffolds.
Despite three published Hevea
genomes now in the public domain,
the discrepancies between the
reports have the logic that the last
word is still not yet in.
The Beijing Genomics Institute,
China; RIKEN, Japan; Universiti
Sains Malaysia; Malaysia Genome
Institute; Centre for Genetic
Engineering and Biotechnology,
Bangkok and CIRAD , France and
Tun Abdul Razak Research Centre,
UK are the leading institutions
involved in genomics research.Leaf blight exterminated
rubber plantations
in Brazil. From this
historical experience,
what are the strategic
initiatives that Asian
rubber growing nations
should take to promote
and protect the Hevea
plantations from similar
disasters that could
happen again? Are we
doing enough in this
field as mere quarantine
policies might not
be enough to fight a
potential leaf blight
disaster?South American Leaf Blight is
a potential threat to all rubber
growing areas. Certainly, mere
quarantine may not be sufficient
enough to check the entry of the
disease. SALB is recognized as abiological weapon by the United
Nations. Spores of Microcyclusulei
(casual fungi of SALB) can remain
on transport. Mass production of
conidiospores and the rapid build-
up of inoculum is the causal step in
the epidemiological development
of fungal infection in flushing
canopies. The conidia are short
lived, whereas the ascospores
produced in black stromatic
structures survive for several
months. These ascospores can
initiate new infection cycles as soon
as susceptible young leaf tissues
are produced by the host.The physiological tolerance of the
isolates to temperature and relative
humidity, as well as to complex
environmental factors, suggests
that the potential for adaptation of
fungal isolates to new environments
is high. This variability underscores
the potential threat of this fungus
to new rubber growing areas
outside South and Central America.
Spores can grow well at 23o C.
Some of the resistance clones are:
FX 3864, RRIM 725, RRIM 711,
IAC 300, IAN 873, FDR 5597, FDR
4575, PMB 1, CDC 312, CDC 308,
CDC 56, FDR 5240 and FDR 5788.
The level of resistance differs from
clone to clone. Introduction of
clones from SALB area is risky. If
the infection escapes Southeast
Asian nations, we are lucky.