G. Holz

DNA homology between Pyrenophora japonica and P. teres

Pyrenophora isolates associated with net- and spot-type net blotch of barley were compared with verified isolates of P. teres f. teres, P. teres f. maculata and P. japonica using total DNA banding patterns, morphology, symptomatology and mating studies. DNA of South African and overseas spot- and net-type isolates digested with Hae III and Msp I showed 74–100 % similarity. Furthermore, spot- and net-type isolates could be mated to produce viable progeny, indicating P. teres to have two-allele heterothallism. Single-ascospores inoculated on differential barley cultivars produced spot, net or mixed symptoms, suggesting that recombination has occurred. Based on the high degree of homology in DNA banding patterns between P. japonica and P. teres f. maculata , as well as similarities in symptom expression on differential cultivars and general morphology, P. japonica is proposed as synonym of P. teres .

Tapesia yallundae collected from wheat stubble in South Africa

Tapesia yallundae var.yallundae is newly recorded from wheat stubble collected near Moorresburg in the western Cape Province of South Africa. Apothecia were observed on wheat stubble incubated for 8 months at 10°C under near-ultraviolet light. Single ascospore isolates produced colonies typical of the Wheat (W)-type in culture. Apothecia were also induced after single-conidial isolates were mated on wheat stubble and incubated at 10–15°C for 6 months. All single-conidial isolates were of the W-pathotype (Ramulispora herpotrichoides var.herpotrichoides).