54 Tyre Asia April/May 2018
RUBBER
In this final and concluding part of the
interview with renowned plant breeder
Dr Mallinath Priyadarshan, he talks
about genomic research innovations
to develop Hevea clones and the
measures that should be in place to
fight a potential leaf blight disasters.
Author of Biology of Hevea Rubber
published by Springer, he shares in
this interview his research experience
spanning over four decades. The first
part of the interview appeared in the
Feb-March 2018 issue of Tyre AsiaMany
aspects of
genome
research TA News Bureau
Development of Asian
rubber plantations
has come a long way
since the set of 22
Hevea rubber seedlings
originally collected from
Brazil by Sir Henry
Wickham arrived in
Singapore Botanical
Gardens in 1877 which
became the gene
repository of modern
Hevea clones. What are
the genomic research
innovations that are
going on in the region
and what is their results/
impact?
Sir Henry Wickham collected
70,000seedsfrom the RioTapajoz
region of the Upper Amazon (Boim
district) and transported the
collection to Kew Botanic Gardens
during June1876. Of the 2,899
seeds germinated, 1911were sent
to the Botanic Gardens in Ceylon- now Sri Lanka –during1876. And
90 per cent of them survived at the
Henarathgoda Botanical Gardens,
one of the six botanical gardens in
Sri Lanka. It is about 29 km from
the country’s capital of Colombo.
DuringSeptember1877, 100 Hevea
plants specified as ‘Cross material’
were also sent to Ceylon. In June
1877, 22seedlings not specified
either as Wickham or Cross were
sent from Kew to Singapore, which
were distributed in Malaya and
formed the prime source of 1000
seedlings tappable trees found by
Ridley during1888. All modern
Hevea clones are believed to
have arisen from the so called 22
Wickham seedlings.The IIRDB expedition during 1981
collected 10,000 odd accessions
from Brazil. Till to date, no clones
got derived from this collection.
The secret is that Wickham
collections underwent several
rounds of natural selections
at several places to end up in
22 seedlings from the original
collection of 70,000 seeds.Genomic research is many fold.
Association mapping, subtractive
hybridization, reverse genetics and
draft genome analysis are some of
them. A comparative evaluation
between self-rooting juvenile clones
(JCs) and bud-grafted (donor)
clones (DCs) at transcriptome level
is one of the most recent research
breakthroughs. Genes, especially
encoding epigenetic modifications,
are differentially expressed in JCs
and DCs.
Genes involved in carbohydrate
metabolism, hormone metabolism
Dr Mallinath Priyadarshan and reactive oxygen species