DNA was extracted from fungal mycelia, grown on PD medium at
32
C, using an improved CTAB method (Zhang et al., 2006). Mating
types
A1 and A2 were identified by the DNA fragments amplified
using primer pairs A1-F/A1-R and A2-F/A2-R respectively, the
design
of which was based on the HD1 and HD2 gene sequences
(HQ343318
and JX15875) of the A1 and A2 alleles in the A mating
type
locus of V. volvacea, strain V23. Mating types A3 and A4 were
identified
by the DNA fragments amplified using primer pairs A3F/A3-R
and A4-F/A4-R respectively, designed according to the HD1
and
HD2 gene sequences (JN578700 and JN578701) of the A3 and A4
alleles
in the A mating type locus of strain PY (Table 1). PCR reaction
mixtures
contained: ddH
◦
O (18.25 L); 2.5 L 10 × buffer solution;
2.0 L dNTP (each 2.5 mmol L
2
−1
); primer, 1 L (10 mol L
);
0.25
L Taq DNA polymerase (5 U L
−1
), 1 L DNA template. Amplification
conditions were: 94
◦
C for 5 mins; 35 cycles of 94
C for
30
s, 51-53
◦
C (see Table 1) for 30 s and 72
C for 1 min; followed by
a
final extension at 72
◦
◦
C for 10 min. PCR products were separated
by
electrophoresis on 1.5% sepharose.
◦
−1