Seed Testing of Maize and Wheat A Laboratory Guide - Search ...

The development of mycelium in
descriptions of 52 and 53 to decide
and b) spores with transverse
Thus, commencing with the
colonies of Stenocarpella
which best fits Stenocarpella
cross walls (septa) so neither is
pycnidia type of fruiting structure,
macrospora is sparse to moderate
macrospora. Alternatively, one can
removed by these two categories.
the possible organisms are:
and some of the remaining
organisms do not fall in this
continue to look through the key at
each characteristic until a character
52 53
48 50 51 52 53
category, so can be eliminated:
is found which eliminates either of
the two numbers: 52 or 53.
The spores of Stenocarpella
Turning now to the length of
13 20 21 27 @ 31 47 @) 52
53 @
Stenocarpella macrospora belongs
to the taxonomic position of
macrospora have a variable
number of septa between 1 - 3.
Only organism 52 has this
conidia, in Stenocarpella
macrospora they are usually at
least 50 ~m in length so would fall
The spores of Stenocarpella
macrospora appear wet in mass,
so a few organisms with spores
appearing dry in mass may be
eliminated:
coelomycetes, but since 52 and 53
fall in this category neither can be
eliminated here.
52 53
character and it proves to be
Stenocarpella macrospora.
52 ®
The correct identity of the organism
under the criterion length 51-80
~m. In this criterion the majority of
organisms do not produce conidia
within a pycnidia and are therefore
eliminated:
@@@@@ 47 52 53
Stenocarpella macrospora spores
are black in mass, and only 47 is
not included here so it is
eliminated:
@ 52 53
Fruiting structures of Stenocarpella
macrospora are a) pynidia, b)
spherical to flask-shaped pycnidia,
and c) pycnidia without setae, but
again both 52 and 53 fall in these
three categories and neither can be
eliminated here.
52 53
has been arrived at in 13 steps by
using the synoptic key in this way.
The shorter alternative is to select
key characteristics and start with
those, irrespective of where they
are situated in the key. Two such
characters for Stenocarpella
macrospora are the presence of
CD0®0@@@@@
@@@@52r@
This leaves 52 as the correct
identification and this has been
arrived at in 2 steps, a simpler
process than starting at the
beginning of the synoptic key.
This leaves 52 and 53. At this point
the simplest option is to look up the
Both 52 and 53, like Stenocarpella
macrospora, have a) brown spores,
pycnidia and relatively long conidia.
iv