Sr10

(Knott and Anderson, 1956) (Plate 3-13)

Chromosome Location

2B (DR Knott, pers. comm. 1993). Federation possesses a resistance gene, presumably Sr10, in chromosome 2B (RA McIntosh, unpublished 1980).

Low Infection Type

0; iN to 3C.

Environmental Variability

Temperature sensitive; sensitivity appears to vary between pathogen isolates (Green et al., 1960; Roelfs and McVey, 1979). More effective at lower temperatures.

Origin

Common wheat; first documented in a Kenyan source and Egypt Na95, a derivative of Kenyan parents. However, more recent work indicated this gene is present in Australian wheats developed prior to 1900.

Pathogenic Variability

Virulence for Sr10 was frequent in North America (Roelfs and McVey, 1979). Luig (1983) reported that Sr10 differentiated between pathogen isolates in South America, Israel and South Africa. Huerta-Espino (1992) found moderate levels of avirulence among cultures from Ethiopia and Turkey and high levels among those from Pakistan, Nepal and China.

Reference Stocks

i: Egypt Na95/4*Marquis (Green et al., 1960) = W2404 (Luig, 1983); Line F = W2691 + Sr10 (Luig, 1983).

v: Egypt Na95 Sr7a Sr9b (Knott and Anderson, 1956); Kenya 117A Sr7a Sr9b (Knott and Anderson, 1956).

Source Stocks

Africa: Kenya Farmer Sr7a Sr9b Sr11 (Green et al, 1960). Other Kenyan wheats (Knott, 1957a, 1957b, 1962a).

Australia: Federation (AP Roelfs, pers. comm. 1993).

North America: Geneva (Sorrells and Jensen, 1987); Lemhi; McNair 1003; Saluda; Springfield. Red Bobs Sr7b (Dyck and Green, 1970). Caldwell Sr7b Sr9d. Benhur Sr8a. Atlas 66 Sr9b.

 

A. and B. Seedling leaves of (L to R): Line F (W2691 + Sr10), W2404 (Marquis + Sr10), Federation, Red Bobs, Marquis, Thew and Norka; infected with A. pt. 34-(4), (7), 10 [P10] and B. pt. 21-0 [p10] and incubated at 23/25°C. Although not distinguishable from the other five resistant lines, the response of Marquis with the first pathotype cannot be due to Sr10 and could be due to Sr19. Both Thew and Norka carry Sr15 but the temperatures imposed were sufficiently high to overcome its effect against these Sr15-avirulent pathotypes. The resistance of Thew to pt. 34-(4), (7), 10 may be due to Sr10. Marquis, Red Bobs and possibly Thew carry a gene(s) conferring IT 3C to pt. 21-0. Both Marquis and Red Bobs carry Sr7b but both cultures are virulent for this gene.

C. Seedling leaves of Line F (W2691 + Sr10) infected with USDA Cereal Rust Laboratory culture LCBB. Courtesy AP Roelfs.

 

Use in Agriculture

Green and Knott (1962) reported that Sr1O conferred adult plant resistance but there are few data to indicate its real value. Roelfs and McVey (1979) noted that this gene was common in spring wheats in western USA. Sr10 was probably transferred by chance through the use of Kenyan material in the CIMMYT program (Knott, 1990).