A review of dipterocarps - Center for International Forestry Research

Seed Physiology 66
Table 5. (continued) Temperatures, moisture contents and germination of mature seeds for the optimum reported
storage conditions.
Species
Optimum storage achieved
Source
Germination Days Temp. MC Other conditions
(%)
(°C) (%)
Shorea parvifolia 40 57 18 35 ventilated incubator Tompsett
99% rh, PB, with perl.,
ventilated weekly
(unpub.)*
Shorea pauciflora 67 45 25 38-51 n/a Sasaki (1980)
Shorea pinanga 50 112 21 46 ventilated incubator Tompsett
99% rh, loose
(unpub.)*
Shorea platyclados 80 58 25 n/a n/a Yap (1981)
Shorea robusta 54 49 15 0 partial vacuum, MC Khare et al.
unknown
(1987)
Shorea roxburghii 52 307 16 36 PB, tied and inflated, Tompsett
ventilated weekly (1985)
Shorea siamensis 83 56 15 40-48 No information. Panochit et
al. (1984)
Shorea smithiana 28 46 26 44 PB sealed and inflated, Tompsett
ventilated weekly (unpub.)*
Shorea sumatrana 60 15 25 n/a n/a Yap (1986)
Shorea trapezifolia 100 63 21 n/a ventilated incubator Tompsett
97% rh, PB, ventilated
weekly, seed was pregerminated.
(unpub.)*
Stemonoporus
20 77 18-21 47 ventilated incubator Tompsett
canaliculatus
99% rh, loose
(unpub.)*
Vatica mangachapoi 24 85 21 40-45 PB, perl. 0% MC, Tompsett
ventilated weekly (unpub.)*
Vatica odorata ssp.
48 148 18 40 ventilated incubator Tompsett
odorata
99% rh, loose
(unpub.)*
Vatica umbonata 10-50 60 10-15 n/a n/a Mori (1979)
*: data based on at least 25 seeds per germination;
**: seed has OLDA storage physiology (orthodox with limited
desiccation ability);
MC: moisture content based on wet weight;
corresponding value for a recalcitrant species is 365
days for Hopea hainanensis. Five recalcitrant species
were stored for over 300 days and a further eight were
stored for over 100 days (Table 5). The three OLDA
species all stored for over 1300 days.
Viability constants
A brief background to viability constants (meaning and
derivation) is given.
The rate at which orthodox and OLDA seeds age in
storage increases with temperature and with moisture
contents between certain limits. Successive samples
from a seedlot of high initial viability in storage will
show progressively lower germination percentages,
perl.: stored in perlite;
sawd.: stored in sawdust;
PB: stored in ventilated polythene bag.
Note: not all reports specified the seed maturity.
producing a curve of germination against time which is
sigmoid in shape. This curve can be transformed by
probit analysis to produce a straight line relationship.
Results from many storage treatments (various moisture
content and temperature combinations) can be analysed
to give constants in a predictive equation. The equation
was developed by Ellis and Roberts (1980a, b) for
herbaceous species and is:
V = Ki - P/10K E - C W log 10 m - C H t - C Q t2 ............. (Eqn 1).
In this equation, V is the predicted viability, K i is the
initial viability, P is the number of days in storage, m is
the moisture content (percentage fresh weight basis) and
t is the temperature ( o C). Viability is expressed as probit
germination. The constants K E , C W , C H and C Q are