Sr30

(Knott and McIntosh, 1978) (Plate 3-31)

Chromosome Location

5DL (Knott and McIntosh, 1978). Sr30 is genetically independent of Pm2 (in 5DS) and Lr1 (Knott and McIntosh, 1978).

Low Infection Type

1+ to 3. Some lines with Sr30 produce lower responses than others (Roelfs and McVey, 1979; Knott, 1990).

Environmental Variability

Low (Roelfs and McVey, 1979).

Origin

Common wheat cv. Webster which was introduced to the USA from Russia.

Pathogenic Variability

Luig (1983) reported that Sr30 was generally effective in North America and Europe, although Roelfs and McVey (1979) mentioned that race 11-RHR was virulent. In Australia, several virulent pathotypes became prevalent after 1968 (Luig, 1983). Virulence was reported as frequent in South Africa (Le Roux and Rijkenberg, 1987a). Huerta-Espino (1992) found virulence in a number of countries with moderate to high levels among samples from Spain, Ethiopia, Turkey, Pakistan and a number of South American countries.

Reference Stocks

i: Sr30/7*LMPG-1; Sr30/7*LMPG-2; Sr30/7*LMPG-3 (Knott, 1990).

v: Festiguay W2706 (Knott and McIntosh, 1978); Webster W973 (Knott and McIntosh, 1978); Mediterranean W1728 (Singh and McIntosh, 1985). Klein Cometa Sr8b (Singh and McIntosh, 1986a).

Source Stocks

Work at The University of Sydney Plant Breeding Institute has demonstrated the presence of Sr30 in several Mexican wheats and Australian derivatives.

Australia: Dollarbird Sr2 Sr8a Sr9g. Hartog (= Pavon ‘S’) Sr2 Sr8a Sr9g Sr12. Batavia Sr2 (heterogeneous) Sr8a Sr12. Houtman Sr2 Sr9gSr17. Rosella Sr5 Sr7b Sr8a Sr12. Lark Sr5 Sr8a. Sunfield Sr5 Sr8a Sr9b Sr12. Osprey Sr5 Sr8a Sr12. Katunga Sr8a. Banks Sr8a Sr9b Sr12; Vulcan Sr8a Sr9b Sr12. Sunstar Sr8a Sr9e Sr12. Lilimur Sr8a Sr17 (heterogeneous). Cranbrook (= Flicker ‘S’)Sr8a Sr9g Sr12 Sr17.

CIMMYT: Lerma Rojo 64A.

 

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A. and B. Seedling leaves of (L to R): Festiguay, Webster, Banks, Condor and Federation; infected with A. pt. 34-1, 2, 3, 4, 5, 6, 7 [P30] and B. pt. 34-1, 2, 3, 6, 7, 8, 9 [p30]. The small degree of resistance of Condor relative to Federation in A. may be due to Sr12.
C. Seedling leaves of (L to R): Lerma Rojo 64A, Mediterranean W2706 and Webster; infected with (L) pt. 34-1, 2, 3, 4, 5, 6, 7 [P30] and (R) 34-1, 2, 3, 6, 7, 8, 9 [p30]. Sr30 is relatively common in Mexican wheats. Courtesy D The.

 

Use in Agriculture

Because of the absence of virulence, Webster was once considered to be almost universally resistant (Hart, 19.31). However, when the resistance was deployed in the Australian cultivar Festiguay, virulent pathotypes increased on this cultivar. These pathotypes declined after Festiguay was withdrawn from cultivation. More recently, a distinctive virulent pathotype was isolated in eastern Australia (Park and Wellings, 1992). Although this pathotype can overcome the resistance of some current wheats with Sr30, it has remained at extremely low levels.