The deployment of diverse sources of resistance in new cultivars underpins durable control of rust diseases. Aus27430 exhibited a moderate level of stripe rust resistance against Puccinia striiformis f. sp. tritici (Pst) pathotypes currently prevalent in Australia. Aus27430 was crossed with the susceptible parent Avocet S (AvS) and subsequent filial generations were raised. Monogenic segregation observed among Aus27430/AvS F₃ families was confirmed through stripe rust screening of an F₆ recombinant inbred line (RIL) population, and the resistance locus was temporarily named YrAW5. Selective genotyping using an Illumina iSelect 90K wheat SNP bead chip array located YrAW5 in chromosome 6A. Genetic mapping of the RIL population with linked 90K SNPs that were converted into PCR-based marker assays, as well as SSR markers previously mapped to chromosome 6A, confirmed the chromosomal assignment for YrAW5. Comparative analysis of other stripe rust resistance genes located in chromosome 6A led to the formal designation of YrAW5 as Yr81. Tests with a marker linked with Yr18 also demonstrated the presence of this gene in Aus27430. Yr18 interacted with Yr81 to produce stripe rust responses lower than those produced by RILs carrying these genes individually. Although gwm459 showed higher recombination with Yr81 compared with the other flanking marker KASP_3077, it amplified the AvS allele in 80 cultivars, whereas KASP_3077 amplified AvS allele in 67 cultivars. Both markers can be used in marker-assisted selection after confirming parental polymorphism.

Common bean is a source of dietary protein and the second most important legume crop in Africa next to faba bean. In Ethiopia common bean is the most important legume as the source of protein and export commodity. Hence, development of commercial varieties is one of the major tasks to meet increasing demand of the stake holders. To this effect, understanding the genetic variability, heritability and association between grain yield and other agronomic traits is necessary for effective plant breeding program. In this context, a field experiment was conducted during 2016/2017 cropping season at Areka Agricultural Research Center in southern Ethiopia with the objective of evaluating common bean genotypes for yield and related traits and also estimate the variability present among the genotypes. Treatments consisted of thirty three common bean genotypes were laid out in a randomized complete block design (RCBD) with three replications. Common bean genotypes exhibited considerable variations for agronomic traits and grain yield. Majority of the traits; plant height, number of nodes, internode length, leaf area, LAI, biological yield, pods per plant, HI and HSW had higher PCV. Genotypic coefficient of variance (GCV) varied from 1.88% to 37.72% with the highest GCV recorded for HSW. Heritability in broad sense (H2) ranged from 0.52% to 95.33% with the highest value observed for HSW. The present study revealed significant variation among genotypes for traits considered except few insignificant traits. In addition, almost all the genotypes were well adapted to the study area and hence, the high yielding genotypes could be directly used as seed sources for production of common bean and some of the genotypes with best diseases resistance reaction, and with high heritability can possibly be used in common bean improvement program.

Wheat production started in Australia around 1788 using early maturing varieties adapted to Australian conditions that were able to escape diseases as well as moisture stress conditions. Wheat production is concentrated on mainland Australia in a narrow crescent land considered as the wheat belt occupying an area of about 13.9 million hectares. Rusts are the most important production constraints to wheat production in the world and Australia causing significant yield losses and decreased the qualities of grains. Wheat is affected by three different types of rust diseases: leaf rust, stripe rust or yellow rust, and stem rust. Each species of the rust pathogen has many races or pathotypes that parasitize only on certain varieties of host species, which can only be traced and identified by differential cultivars. Pathotype surveillance is the basis for information on the virulence or pathogenic variations existing in a particular country or wheat growing region of the world. Studies in pathotype variation are conducted in controlled environments using multi-pathotype tests. The currently cultivated commercial wheat varieties of Australia possess leaf rust resistant genes: Lr1, Lr3a, Lr13, Lr13+, Lr14a, Lr17a, Lr17b, Lr20, Lr23, Lr24, Lr26, Lr27, Lr31, Lr34, Lr37, and Lr46; stem rust resistance genes: Sr2, Sr5, Sr8a, Sr8b, Sr9b, Sr9g, Sr11, Sr12, Sr13, Sr15, Sr17, Sr22, Sr24, Sr26, Sr30, Sr36, Sr38, and Sr57; and stripe rust resistance genes: Yr4, Yr9, Yr17, Yr18, Yr27, and Yr33. This paper discusses the historical and current significance of rusts to wheat production in the world with particular reference to Australia viz-a-viz detail description of each of the three rusts and their respective virulence variations through the resistance genes deployed in the commercial cultivars.

Smallholder wheat farmers of Ethiopia frequently use landraces as seed sources that are low yielders and susceptible to diseases due to shortage of seeds of adapted improved bread wheat varieties. Developing novel improved varieties with wider adaptability and stability is necessary to maximize the productivity of bread wheat. Hence, a multi-location field trial was conducted across four locations in south Ethiopia during the 2022/23 main cropping season with the objective of estimating the magnitude of genotype by environment interaction (GEI) effect, and determine the stable genotype among the 10 Ethiopian bread wheat advanced selections using a randomized complete block design (RCBD) with three replications. The data recorded from all plots on 13 agronomic traits and the three wheat rust diseases were computed using appropriate statistical software. The results showed that individual and combined analysis of variance (ANOVA) exhibited the presence of highly significant variability (P<0.01) among the locations, genotypes, and GEI effects for most of the traits including grain yield. The additive main effects and multiplicative interaction (AMMI) ANOVA for main effects; location, genotype and GEI revealed significant variation among the selections with 82.0%, 8.7% and 9.3% share of sum square variation, respectively. The genotype plus genotype by environment interaction (GGE) bi-plot analysis explained 92.44% of the total variation observed. AMMI and GGE-biplot analyses indicated G11, G9, G10, and G8 as high yielders and well-adaptive in the favourable locations. AMMI stability value (ASV) and Yield stability index (YSI) showed G5 and G8 as highly stable and adaptive selections across locations. Overall, the study identified that G8 as the most stable and adaptive selection, while G11 was the top yielder cultivar across locations. Therefor it was suggested that seeds of G8 can be grown across all the locations, whereas G11, G9, and G10 can be grown in the favourable environments and similar agro-ecologies in the east African region.

Stem rust caused by Puccinia graminis f. sp. tritici (Pgt) is one of the most important diseases of wheat worldwide. Breeding for resistance to diseases is the most important approach for mitigation of yield losses. This study was conducted to estimate the diversity of all stage stem rust resistance (ASR) genes on the 142 durum wheat landrace accessions at seedling stage. The study was conducted in greenhouse at Ambo Plant Protection Research Center on the 142 durum wheat landrace accessions using 20 differential lines, one susceptible line (McNair), and eight Pgt races. The result depicted the presence of Sr7b, Sr8a, Sr9b, Sr10, Sr11, Sr13, Sr17, Sr30, Sr31, Sr36, and SrTmp in the Ethiopian durum wheat accessions. Among the 142 durum wheat accessions, 83 accessions were identified for possessing single ASR genes, and four accessions including the universal susceptible line (McNair) did not have effective resistance genes to the pathogen races tested in this study. The remaining 55 accessions had either a combination of two resistance genes, unknown number and kind of genes, or unidentified genes displaying resistance across all the pathogen races. This study demonstrated the prevalence of significant genetic diversity for stem rust ASR genes in the Ethiopian durum wheat landraces.