Genetic control of oat rust diseases
Jõgeva Plant Breeding Institute, 48309 Jõgeva, Estonia
Oat grain is indicated to be of great value, especially for its favourable effects on the health of humans and animals. Food and feed industries can utilise only fully developed and faultless oat grain that can be harvested from healthy, unattacked plants. Cultivating disease-resistant varieties seems to be an optimum alternative to chemical control. Growing of the resistant varieties is the most effective biological control of diseases. It is highly economic and ideal from the ecological point of view. Disease resistant varieties are the basic precondition for successful sustainable (organic) agriculture. Stem rust (Puccinia graminis Pers. f. sp. avenae Erikss. et Henn) and crown rust (Puccinia coronata Cda. f. sp. avenae Erikss.) are the potentially destructive diseases of oat crop in Estonian conditions. The effectiveness of resistance sources to Puccinia coronata and Puccinia graminis was tested in the framework of the European and Mediterranean Oat Disease Nursery (EMODN) at Jõgeva Plant Breeding Institute in 1996–2002. Highly resistant to crown rust were Pc-gene lines Pc 39, Pc 54-2, Pc 59, Pc 60, Pc 68 and Pen2xCAV1376. The greatest change in crown rust incidence was recorded for Pc 58 and Pc 61. These lines were completely free from disease infection at the beginning of the trial cycle, but, in 2001, were attacked at a moderate level (5–6 points in 9-point scale). The differential ‘Pirol’ and the varieties ‘Alo’, ‘Jaak’ and ‘Edit’ of the Estonian Variety List lost resistance to crown rust in 1998. Effective stem rust resistance against Puccinia graminis f. sp. avenae were conferring Pg-gene lines Pg 15, Pg a and Rodney ABDH. The first report of virulence on Pg 13 in Europe was detected in the framework of EMODN trials in Estonia in 1993.