Francki M

Golzar H

Loughman R

Shankar M

Walker E

Wilson R

English

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Identification and genetic characterisation of a powdery mildew resistance gene in wheat  Shankar M1, Francki M1, 2, Walker E1, 2, Golzar H1, Wilson R1 and Loughman R1 Department of Agriculture and Food, 3 Baron-Hay Court, South Perth, WA 6151, Australia, 2WA State Agricultural Biotechnology Centre  Studies were conducted to determine the inheritance of resistance to powdery mildew (PM) by Blumeria graminis f.sp. tritici in a resistant (R) CIMMYT line 6HRWSN125 and in the resistant cultivar Meri.  Resistance was assessed at the seedling stage in a doubled haploid (DH) population (6HRWSN125/WAWHT2074) and in three Meri-based crosses including Meri/Ajana, Meri/Wyalkatchem and Meri/6HRWSN125.  Line WAWHT2074 and cultivars Ajana and Wyalkatchem are susceptible (S) to powdery mildew strains in Western Australia.  The DH population showed a segregation ratio not significantly different from 1R:3S (χ2 = 1.5, P = 0.22) indicating complementary gene interaction of two genes for PM resistance.  Crosses Meri/Ajana and Meri/Wyalkatchem produced S F1 progeny and an F2 segregation ratio of 1R:3S (χ2 = 0.5 and 3.6, P = 0.48 and 0.06), suggesting the presence of a single recessive gene in Meri.  The hypothesis was confirmed in the F3 where a non-random selection of F3 families was examined for segregation of resistance.  F3 families arising from R F2 plants were all true breeding R while F3 families from S F2 plants either segregated or were true breeding S.  The Pm locus was mapped in Meri/Ajana and Meri/Wyalkatchem to the proximal region on chromosome 3BS, a region not previously identified to contain Pm resistant genes.  The cross between the resistant cultivar Meri and the resistant line 6HRWSN125 produced R F1 progeny.  The F2 progeny segregated in a ratio of 43R:21S (χ2 = 0.8, P = 0.36) which supports the hypotheses of two dominant complementary genes in 6HRWSN125 and one recessive gene in Meri.  Presence of different resistant genes in parents 6HRWSN125 and Meri was confirmed in F3 where F3 families from R F2 plants either segregated or were true breeding R while F3 families from S F2 plants were all true breeding S. 

Identification and genetic characterisation of a powdery mildew resistance gene in wheat

https://ses.library.usyd.edu.au/bitstream/2123/3262/1/P159.pdf

Identification and genetic characterisation of a powdery mildew resistance gene in wheat

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