TITLE:
Variation in Telial Formation of Puccinia striiformis in the United States
AUTHORS:
Anmin Wan, Meinan Wang, Xianming Chen
KEYWORDS:
Puccinia striiformis, Stripe Rust, Telial Formation, Wheat
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.5,
May
30,
2019
ABSTRACT:
Puccinia striiformis, the causal agent of stripe rust in wheat, barley,
and various wild grasses, produces urediniospores and teliospores on these
primary or auxiliary hosts. Telial
formation, which stops producing infectious urediniospores, is affected by
various host and environmental conditions. However, it is not clear if variation
exists among different isolates in the United States. To determine the
differences in the pathogen population, 1423 isolates collected in the United
States from 2013 to 2016 were tested for telial
formation in the seedling stage at a diurnal temperature profile of 4°C - 20°C.
The percentages of telial formation
varied greatly among the isolates. Of the 1423 isolates, 62.97% produced telia
with the percentages of telial formation
ranging from 1% to 95% under the test conditions. The formation of telia was
significantly affected by the year and the month when the isolates were
collected. The epidemiological regions or states, host plants (wheat, barley,
and grasses), and races of the isolates did not significantly affect telial formation. However, significant effects
on telial formation were observed by
interactions between year and region, year and race, month and region and among
year, month, and region, as well as between year and month. The results showed
that telial formation is a complex trait
under the genetic control of the pathogen isolates for adaptation to different
environments. Further studies are needed to identify genes involved in the
formation of telia and the relationship of telial
formation to the survival, aggressiveness, fitness, and evolution of the
pathogen.