Viability and virulence of wheat leaf rust agent (Puccinia triticina Eriks.) isolates after long term preservation

The State Collection of phytopathogenic microorganisms (ARRIP) accumulates a great number of wheat leaf rust agent ( Puccinia triticina Eriks.) isolates, an extremely harmful and epiphytotic pathogen. Annually the collection is replenished with new leaf rust isolates from different populations. Annual estimation of the virulence genes’ frequency in isolates makes it possible to track the dynamics of the fungal populations. One of the main tasks of the State collection is to preserve the isolates of the fungus without losing their biological properties to involve these isolates in further laboratory and field experiments. For this purpose, the viability and virulence of P. triticina collection isolates was evaluated during 10-year preservation in a household refrigerator (+4 °С) and in a REVCO freezer (-80 °С, Revco, USA). We used 124 P. triticina isolates collected in 2005, 2006, 2008, 2009, 2010 and 2012 from damaged wheat ( Triticum aestivum L.) samples in the Central, North Caucasus and West Siberian regions of the Russian Federation...