This collection includes results of rust screening of advanced breeding lines of bread wheat, barley, and oats with identified rust pathotypes in the greenhouse and in field between 2018 and 2022. Greenhouse rust testing was conducted at the USYD plant breeding institute in Camden, while in field rust testing took place in three sites; two in Camden, NSW (“Lansdowne” and “Horse Unit”) and one in Karalee, QLD. Cereal breeders submitted material to be screened for disease response, rust pathotypes used in both greenhouse and field testing were chosen with the objective of identifying industry-wide resistant cultivars. A Fee for Service (FFS) program was subsidised by GRDC for barley and oat testing. These datasets with raw scores are stored on the USYD-RDS at \\shared.sydney.edu.au\research-data\PRJ-ACRCP_prebreeding. All wheat rust data including raw and interpreted scores can be found on the NVT website https://nvt.grdc.com.au/ Contingency tables summarizing the frequencies of tests per crop per year and the presence/absence of pathotypes in seven main pathogens per year can be accessed. If required access to the datasets with the raw rust score can be also requested. Greenhouse and Field experiments - In greenhouse tests. Location: PBI - Camden 10-15 seedlings were raised in 9cm diameter pots initially treated with a complete fertilizer, and after 6 -7 days with a nitrogenous fertiliser. Seedlings were inoculated with each rust pathotype at the 1-2 leaf stage by atomizing urediniospores suspended in a light mineral oil - rate (1.0mg urediniospores/1.0ml oil per 200 pots) - using a hydrocarbon propellant pressure pack. Inoculated seedlings were then incubated either: a) overnight at ambient temperatures in a dark room in which mist was generated by an ultrasonic humidifier (leaf rust on wheat and barley, oat crown rust); for 48 hours in a humidity chamber (100% RH) within a greenhouse growth room in which the temperature is maintained between 20-25°C (stem rust on wheat, barley, and oats); or b) overnight on trolleys with in-built water baths, covered with polythene hoods and incubated at 10-12°C (stripe rust of wheat and barley). Following dew treatment, infected seedlings are transferred to greenhouse growth rooms in which temperature was maintained within the range 17-18°C or 20-25°C, depending upon the rust pathogen. Disease assessments followed the “0”-“4” infection type scoring system. Two levels of testing: • Routine greenhouse: it tested the most appropriate single rust isolate, for determination of seedling resistance or susceptibility, and possibly speculation with respect to the resistance gene present in resistant lines. Most Routine Tests involved stem rust because of the resistance to this pathogen in Australian wheat germplasm is principally based on All Stage Resistance (ASR) (eg genes/ gene combinations of Sr24, Sr26, Sr38) and the ability to detect the durable APR gene Sr2 in seeding tests. • Detailed: it involved multi-pathotype testing with an array of up to 12 key pathotypes per rust species. Seedling data collected in the Greenhouse against specific pathotypes of oat (crown rot) and barley the reaction score on an standarized scale. P = number of plants. ; = fleck. The leaf has small necrotic flecks. Very resistant 1 = small uredia. Resistant to moderately resistant 2 = small to medium size uredia 3 = medium sized uredia with or without chlorosis 4 = Large uredia ‘-‘ and ‘+’ indicate less than average for that class and greater than average for that class, respectively. C is more chlorosis than usual N is more necrosis than usual. Where there is more than one infection type on the leaf, 2 or more scores are used. A comma (,) indicates there is heterogeneity between plants in the line tested. Reference: McIntosh, R.A, Wellings, C.R. and Park, R.F. 1995. Wheat Rusts: An Atlas of Resistance Genes. CSIRO Publications. - Field studies of adult plant responses (APR). Location: At least 3 field sites are used for these tests: “Karalee”, “Lansdowne”, “Horse Unit”. Artificial rust epidemics were created. Automated seeder magazines were sent to clients early each year, along with seed of susceptible spreader genotypes. Each client packs the magazines with lines to be tested among which plots of the spreader genotypes were regularly interspersed. About a month before planting, rows of the susceptible spreader genotypes were sown along the borders of the bays into which the lines for testing were later sown. After sowing, irrigation lines were set and pre- and post-emergence herbicides applied. The spreader rows were inoculated using a suspension of urediniospores of the relevant pathotype(s) prepared in a light mineral oil at 0.3 g/L. The suspension is misted over spreader rows using an ultra-low-volume applicator on at least 5 mid-winter evenings when there is a high likelihood of dew formation overnight. Field plots are scored using either a modified Cobb scale that incorporates both percent leaf area affected and host response (eg 10 MR, 50MS, 90S). Data is captured electronically and returned to breeders if contracted to do so. Many breeders chose to do the scoring and selections themselves. -- Barley rust scores. Field score based on modified Cobb Scale (Disease severity combined with Host response) Disease severity (% leaf area effected) 0-100 scale Host response R = resistant TR = Trace resistant MR = moderately resistant MS = moderately susceptible MRMS = overlapping of MR and MS MSS = moderately susceptible to susceptible S = susceptible , (comma) sseparating scores indicates segregation in response 13 Datasets were generated and used for the analyses for both GH and in field. Variables used in field datasets: • Breeding Company name • Entry number/variety name • Field/Host scores Variables used in greenhouse datasets: • Breeding Company name • Entry number/variety name • Pathotype • Gene postulation/Reaction Class Seedling -- Oats rust scores/datasets Field score on 1-9 scale where 1 is resistant and 9 very susceptible. 23 Datasets (some between years 2018 - 2022) were generated for the analyses for both GH and in field. Variables used in field datasets: • Breeding Company name • Entry number/variety name • Field/Host scores Variables used in greenhouse datasets: • Breeding Company name • Entry number/variety name • Pathotype • Gene postulation/Reaction Class Seedling Data was captured electronically and returned to breeders if contracted to do so. Many breeders chose to do the scoring and selections themselves. For further enquiries please contact: Dr. Robert Park at robert.park@sydney.edu.au Dr. Laura Ziems at laura.ziems@sydney.edu.au