Annual Report 2006

using dormant winter buds. Also, we started
three cryopreservation projects such as
practical storage of -grown potato
shoots, development of cryopreservation protocol
of mat rush and sugarcane. In these, practical
cryopreservation method of -grown
potato shoot tips by encapsulation-vitrification
was improved. Mass propagation system of
-grown mat rush shoots was established
using induction of multiple shoots.
Morphological, molecular and
phytopathological variations of
(van Beyma) M.E.
Palm, W. Gams & Nirenberg, which was validly
described in 1995 (Palm et al. 1995), had been
known as a common soil fungus at rhizospheres,
and was isolated from lake sediment for the
first time in Japan (Tubaki and Ito, 1975). We
identified several fungal isolates pathogenic to
plants, pumpkin, garden ranunculus, anemone,
sweet pepper, lotus ginger and Japanese radish
(Fig. 3), as and found that it had
been differentiated morphologically, molecularly
and phytopathologically. The isolates used are
shown in Table 1. Their morphological
characters are as follows (Fig. 4). Colonies in
culture on potato dextrose agar (PDA) at 20in
the dark are flat with little aerial mycelium,
smooth and cream to salmon or pale brown in
color. Conidiophores are unbranched or
occasionally branched, with conidiogenous cells
often arising at right angles from vegetative
hyphae. Conidiogenous cells are monophialides
or rarely polyphialides formed at the apices, or
as short (adelophialides) or long blanches from
vegetative hyphae, hyaline, smooth, cylindrical
to obclavate, sometimes crooked or sinuous at
the tips, often with single conidiogenous
apertures, and occasionally with second
apertures. Conidia are produced in colorless
slime masses at the tips of the phialides, hyaline,
smooth, oblong-ellipsoidal, usually asymmetrical
to slightly curved, multiguttlate and most are 1-
septate and with a few aseptate.
Growth speed of mycelia and appearance
rates of aseptate conidia on PDA at 20in the
dark varied from 2.7-4.7 mm/day and 0-28.6%,
respectively, in 6-8 isolates. Sizes of septate and
aseptate conidia that had formed on synthetic
low nutrient agar (SNA) at 20in the dark
ranged from 4.0-12.01.0-5.5 µm and 2.5-8.51.0-
3.5 µm, respectively, depending on the isolates.
The 10 isolates were classified into 2 groups
based on their sequence data of rDNA ITS
Fig. 3
Diseases of pumpkin (A), garden ranunculus (B),
anemone (C), sweet pepper (D) , lotus ginger (E) and
Japanese radish (F) caused by
Fig. 4
Colonies of on potato dextrose agar
plates (upper left: surface view, upper right: reverse
view), conidiogenous cells and conidia of
(lower left: an isolate from pumpkin, lower right: an
isolate from ranunculus)