Reactions of Argentine and Australian Sunflower Rust Differentials to Four North American Cultures ofPuccinia helianthifrom North Dakota

Abstract

Kochman and Goulter, and Luciano and Yang, S.-M., Antonelli, E. F., Luciano, A., and Luciani, N. D. 1986. Reactions of Argentine and Luciani to the four North American (NA) Australian sunflower rust differentials to four North American of Puccinia helianthi from of P. helianthi had not been North Dakota. Plant Disease 70:883-886. determined before this study. The current system of naming of Four North American (NA) (1, 2, 3, and 4) of Puccinia helianthi were tested on 12 pheliant istel o sunflowe Argentine (six from Antonelli [A] and six from Luciano and Luciani [LL] and three Australian P. helianthi is not helpful to sunflower (from Kochman and Goulter [KG]) rust differential cultivars and lines of sunflower (Helianthus breeders selecting appropriate parental annuus). Impira INTA NAL (LL) and Guayacan INTA NAL (LL) were susceptible to all four NA material to breed for resistance or to rust cultures; Morden 307-1 (A,LL) and 29-3-1-3-21 (KG) were susceptible to NA 2 and 4; sunflower pathologists looking for Guayacan INTA sel. Castelar (A) and F164A (LL) were susceptible to NA 3 and 4; relationships between new and old Pergamino 71/ 538 (A) was susceptible to culture 2 but resistant to 4; Impira INTA sel. 11 Castelar (13). Recently, three systems of naming was susceptible to culture 3 but resistant to culture 4; FI64A X Morden 307-1 (LL), 953-88-3-1-54 of P. helianthi have been proposed (KG), and 953-102-1-1-41 (KG) were susceptible to culture 4. INTA sel. 5 Castelar (A), Pergamino (9,13; E. F. Antonelli, unpublished) at the 78/287 (A), Saenz Pefia 74-1-2 (A), and P386 (LL) were resistant to the four NA cultures. We 1 1th International Sunflower Conference hypothesize that the genes that condition rust resistance in Antonelli's Impira INTA sel. 5 Castelar, held at Mar del Plata, Buenos Aires, Impira INTA sel. 11 Castelar, Pergamino 71/538, Pergamino 78/287, Saenz Peha 74-1-2, and Luciano and Luciani's P94A and P386 are different from the genes R, and R2 that were found in Argentina, in March 1985. CM 90RR (or Guayacan INTA sel. Castelar or F164A) and CM 29-3 (or 29-3-1-3-21 or Morden Sackston et al (13) proposed using 307-1), respectively. We propose using the term cultures instead of races in studies on the avirulence/virulence formulas based on genetic relations of sunflower rust systems. A list of sunflower rust differentials is suggested for known effective/ ineffective genes to documenting the corresponding pairs in the sunflower rust systems and pathogenicity designate of P. helianthi on formulas are proposed for describing the of P. helianthi. sunflower. This system cannot show that there is a gene for virulence and a gene for susceptiblity (L. E. Browder, Rust of sunflower (Helianthus annuus different from those of Luciano and personal communication). This system of L.) caused by Puccinia helianthi Schw. is Luciani. The relationship between naming can be hypothetical until one of the most destructive diseases of Luciano and Luciani's and the resistance genes in the differentials are sunflower in the world. P. helianthi is Antonelli's is unknown. The identified. composed of (cultures) of varying susceptibility of sunflower rust dif- Kochman and Goulter (9) also