C. Gall et al., TETRAD ANALYSIS OF ACID-PHOSPHATASE, SOLUBLE-PROTEIN PATTERNS, AND MATING-TYPE IN LEPTOSPHAERIA-MACULANS, Phytopathology, 84(11), 1994, pp. 1299-1305
We investigated the utility of mating type, soluble protein profiles o
btained after isoelectric focusing, and acid phosphatase (ACP) pattern
s as genetic markers for the blackleg fungus, Leptosphaeria maculans.
Fertile matings were obtained in vitro by pairing single-ascospore iso
lates. A method for dissecting asci and recovering the eight component
ascospores was developed that allowed tetrad analysis. Protein electr
ophoresis revealed limited polymorphism among the 73 single-ascospore
field isolates. Only one isolate (H5) displayed a different soluble pr
otein profile (SPP), termed SPP-, characterized by one missing band an
d one additional band. We found three ACP patterns in our collection.
Protein profiles and ACP patterns were mitotically and meiotically sta
ble. A 4:4 segregation ratio in asci was obtained for mating type, SPP
, and ACP patterns, suggesting that each marker was controlled by a si
ngle gene. Mating type and ACP genes seemed to be independent. The rel
iability of the crossing protocol and the Mendelian segregation of the
markers following in vitro meiosis mean that this fungus is now amena
ble to genetic analysis of pathogenicity.