Molecular profiling demonstrates limited diversity amongst geographically separate strains ofUstilago scitaminea

Abstract

Intraspecies diversity within Ustilago scitaminea isolates from South Africa, Reunion Island, Hawaii and Guadeloupe was assessed by RAPDs, bE mating-type gene detection, rDNA sequence analysis, microscopy and germination and morphological studies. Except for sequence data, the other analyses yielded no differences in the isolates that could be used in a phylogenetic separation. Mycelial DNA of the SA isolate shared 100% sequence identity with that of mycelial DNA cultured from in vitro produced teliospores of the parent cultivar. Overall the ITS1 and ITS2 regions were found to have 96.1% and 96.9% sequence identity with a total of 17 and 21 base changes, respectively, amongst the isolates. The Reunion Island isolate was shown to be most distantly related by 3.6% to the other isolates, indicating a single clonal lineage. The lack of germination in teliospores from Guadeloupe may be attributed to changes in temperature and humidity during transportation.

Evidence for the dispersal of a unique lineage from Asia to America and Africa in the sugarcane fungal pathogen Ustilago scitaminea

“…In contrast, they have observed a higher level of polymorphisms among U. scitaminea Asian strains (Taiwan, Thailand, Philippines). RAPD markers also revealed the lack of polymorphism between strains from South Africa, Louisiana, Hawaii and Reunion Island (Singh et al, 2005). In our study, the single worldwide lineage was also detected in some Asian countries such as Indonesia and Thailand.…”

Biogeographical Variation and Population Genetic Structure ofSporisorium scitamineumin Mainland China: Insights from ISSR and SP-SRAP Markers

“…Molecular detection of the smut pathogen in sugarcane was firstly realized by using polymerase chain reaction (PCR) and then TaqMan Real-time PCR to amplify the bE mating-type gene of S. scitamineum [5, 18, 19]. The intraspecies diversity within S. scitamineum isolates has been studied by the methods of random amplification of polymorphic DNA (RAPD) [6, 20], amplified fragment length polymorphism (AFLP) [4], and internal transcribed spacer (ITS) sequence analysis [21, 22]. Raboin et al analyzed a collection of S. scitamineum populations from 15 sugarcane producing countries for polymorphisms at 17 microsatellite loci [9].…”

“…These analyses also did not provide information about the race differentiation of S. scitamineum . Furthermore, the numbers of host genotypes, smut isolates, and geographical origin of districts in China for testing were limited to 21, 23, and 6, respectively, in the study of Que et al [7], and the smut isolates studied by Raboin et al [9] and Singh et al [6] did not include the isolates from Mainland China. Thus, to better understand the smut population structure and the influence of environmental and genotype heterogeneity on the population structure, analysis of more isolates representing more regions, more cultivar/genotypes, and a representative sugarcane variety in different regions is needed.…”

Identification and Characterization of the Causal Organism of Gummy Stem Blight in the Muskmelon (Cucumis meloL.)

“…A comparison of DNA components in the ribosomal unit, such as the 5.8S, 18S, and 28S RNA encoding genes in fungi, allows separation of organisms at the gene level. The internal transcribed spacer (ITS) is more specific region for distinction at the species level [10]. Thus, the objective of the present study was to identify the causal agent of gummy stem blight in muskmelon by conducting a morphological examination and a sequence analysis of the ITS region of rDNA.…”