Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/15/1998
Publication Date: N/A
Technical Abstract: Tilletia barclayana (Bref.) Sacc. & Syd. is a complex of several taxa, including T. horrida Tak. Recent studies suggest that T. horrida, the rice kernel smut pathogen, is not a member of this complex. In order to determine if teliospores of T. horrida can be morphologically distinguished from the other taxa, teliospores from type specimens of taxa in this complex were examined with scanning electron and light microscopy. All members of the complex produce brown, globose to subglobose teliospores with exospores of pointed to truncate curved spines, a gelatinous sheath, and occasionally a short apiculus. Exospore ornamentation of T. ajrekari and T. horrida is coarser and more widely spaced when compared with that of other taxa in this complex. Tilletia horrida teliospores range from 21.9- 41.4 um in diam. (mean=29.0 um). Teliospores of T. ajrekari range from 15.9-25.4 um (mean=20.1 um). Teliospores of T. barclayana and T. pennisetina range from 20.0-28.5 um and 23.6-33.4 um (mean=24.2 and 28.7 um), respectively. Teliospores of T. pulcherrima and T. pulcherrima var. brachiariae range from 21.1-29.5 um and 19.7-25.8 um (mean=25.1 and 22.5 um), respectively. While morphological characters among these taxa intergrade, T. ajrekari and T. horrida can be distinguished from the other tax in this complex. The issue of generic placement of these fungi also is discussed.