Genetics of new sources of rust resistance, backcrossing in wheat & overseas testing for stem rust Harbans Bariana

Genetics – APR to stem rust  Burrion (Sr31+APR)/LB - Two APR genes in Kenya  AWCC993/Yitpi - Monogenic segregation  AWCC1141/Yitpi - Monogenic segregation 2

Genetics – APR to leaf rust  Genetic analysis of two landraces showed digenic segregation  Monogenically segregating populations (MSPs) were isolated  Five MSPs are confirmed and genomic location studies are in progress  Two gene segregation was noted in Sonora/BT Schomburgk (BTS) population. One slow rusting minor gene is contributed by Sonora and a major gene is contributed by BTS  Monogenic segregation for an APR gene from Westonia was noted in a cross made for stripe rust resistance analysis 3

Genetics –APR to stripe rust  Trigenic segregation in Sonora/BT Schomburgk (BTS) population. Sonora appear to contribute one race-specific and one APR gene. One APR is contributed by BTS  BC1F2 analysis of Wollaroi/2*NYB3 cross confirmed segregation of 3 to 4 genes for adult plant stripe rust resistance 4

Genetics –Seedling resistance stripe rust  A new widely effective gene for stripe rust resistance was shown to be linked closely in repulsion with Yr4  Genetic analysis based on Frelon/NYB3 F3 population demonstrated the presence of one more gene in addition to Yr17 5

Genetics – Durum wheat  Wollaroi showed infection type 23n to 3n in the seedling stage. This phenotype segregated with Qyr.sun-2A which explains 9 to 12% phenotypic variation. Request to name this locus has been sent to Bob McIntosh. It is likely to be named Yr56.  Identified new sources of resistance against durum leaf rust pathogen, populations are being developed.  An F5 population of a durum genotype carrying APR to stem rust will be phenotypes in 2013  Tamaroi/Bansi F6 population showed monogenic segregation for leaf rust resistance against wheat leaf rust pathogen 6

Triple rust resistant donor development through backcrossing  Yr40/Lr57 – Five backgrounds  Lr49,Lr13, Lr34 - four backgrounds  Yr47/Lr52 – Four backgrounds  Yr35/Lr53 – Five backgrounds  Lr67/Yr46/Sr55 – Three backgrounds  Yr49 – Initial crosses made in four backgrounds  Yr37/Lr54 – Initial crosses made 7

Amelioration of donors  Sr50 - it was highly susceptible to stripe rust and has been crossed with Yr40/Lr57 and Yr47/Lr52  Yr49 - It was highly susceptible to leaf rust and stem rust. It has been crossed with lines leaf rust and stem rust resistant donors  Yr34 - It is also being improved for leaf rust and stem rust resistance  Sr39 (shortened segment ) has possibly lost leaf rust resistance and it was crossed to top up leaf rust resistance 8

Ug99+Sr24 Screening Bullet, Cadoux, Condor, Clearfield JNZ, Dakota, Gabo, Gamenya, GBA Sapphire, Janz, Kidman, Meering, Mitre, Petrie,, Waagan, – Sr28 type resistance, Bolac, Crusader, Carinya, EGA Wentworth - Other than Sr28 9

Potential threats ›Durum leaf rust races ›Ethiopian and Indian stem rust races -(Sr13 virulence) 10

Response to American leaf rust pathotypes CA AZ 103 ATHBJ Bellaroi3+;; Caparoi3+;; Gundaroi3+;; Hyperno3+;- Jandaroi3+3-;1- Saintly3+;; Kalka3+;; Tjilkuri3+;; WID8023+;; WID8033+ Wollaroi3+;2-; Yallaroi Tamaroi3+ ;1- Kamilaroi3-;1-; 11

Kenya - Ug99+Sr24 GenotypesRust response seg B Bellaroi67 Caparoi5,3,2 Hyperno2,45 Jandaroi34 Kalka23,5 Saintly3 Tamaroi5,3 Tjilkuri23,4 Wollaroi5 12

Ethiopia - Sr13 virulence GenotypesRust response seg Arrivato5 TO 6 Bellaroi67 Caparoi67 Gundaroi7 Hyperno6 Jandaroi5 Kalka67 Kamilaroi7,5 Saintly6 Tamaroi7 Tjilkuri67 WID80267 WID80356 Wollaroi5E, 78L Yallaroi7 13

Summary  Focus is to characterize APR genes other than known  Facilitate release of triple rust resistant varieties for growers through provision of resistance donors  National and international training 14

Thank You 15 IARI RRS, Wellington, IndiaKARI, Njoro, Kenya PBI, Cobbitty, Australia 98-1,2,3,5,6, ,2,7+Sr38 40A – Sr24 Ug99+Sr24