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Ethiopia is considered a center of origin and diversity for durum wheat and is endowed with many diverse landraces. This research aimed to estimate the extent and pattern of genetic diversity in Ethiopian durum wheat germplasm. Thus, 104 durum wheat genotypes representing thirteen populations, three regions, and four altitudinal classes were investigated for their genetic diversity, using 10 grain quality- and grain yield-related phenotypic traits and 14 simple sequence repeat (SSR) makers. The analysis of the phenotypic traits revealed a high mean Shannon diversity index (H′ = 0.78) among the genotypes and indicated a high level of phenotypic variation. The principal component analysis (PCA) classified the genotypes into three groups. The SSR markers showed a high mean value of polymorphic information content (PIC = 0.50) and gene diversity (h = 0.56), and a moderate number of alleles per locus (Na = 4). Analysis of molecular variance (AMOVA) revealed a high level of variation within populations, regions, and altitudinal classes, accounting for 88%, 97%, and 97% of the total variation, respectively. Pairwise genetic differentiation and Nei’s genetic distance analyses identified that the cultivars are distinct from the landrace populations. The distance-based (Discriminant Analysis of Principal Component (DAPC) and Minimum Spanning Network (MSN)) and model-based population stratification (STRUCTURE) methods of clustering grouped the genotypes into two clusters. Both the phenotypic data-based PCA and the molecular data-based DAPC and MSN analyses defined distinct groupings of cultivars and landraces. The phenotypic and molecular diversity analyses highlighted the high genetic variation in the Ethiopian durum wheat gene pool. The investigated SSRs showed significant associations with one or more target phenotypic traits. The markers identify landraces with high grain yield and quality traits. This study highlights the usefulness of Ethiopian landraces for cultivar development, contributing to food security in the region and beyond.

Key message Linkage disequilibrium (LD)-based haplotyping with subsequent SNP tagging improved the genomic prediction accuracy up to 0.07 and 0.092 for Fusarium head blight resistance and spike width, respectively, across six different models. Abstract Genomic prediction is a powerful tool to enhance genetic gain in plant breeding. However, the method is accompanied by various complications leading to low prediction accuracy. One of the major challenges arises from the complex dimensionality of marker data. To overcome this issue, we applied two pre-selection methods for SNP markers viz. LD-based haplotype-tagging and GWAS-based trait-linked marker identification. Six different models were tested with preselected SNPs to predict the genomic estimated breeding values (GEBVs) of four traits measured in 419 winter wheat genotypes. Ten different sets of haplotype-tagged SNPs were selected by adjusting the level of LD thresholds. In addition, various sets of trait-linked SNPs were identified with different scenarios from the training-test combined and only from the training populations. The BRR and RR-BLUP models developed from haplotype-tagged SNPs had a higher prediction accuracy for FHB and SPW by 0.07 and 0.092, respectively, compared to the corresponding models developed without marker pre-selection. The highest prediction accuracy for SPW and FHB was achieved with tagged SNPs pruned at weak LD thresholds (r2

The breeding of new cultivars is a powerful approach to increase both the quantity and quality of potato harvest per land unit. The aim of this research was to determine using multi-site testing the progress made by the genetic enhancement of potato in Sweden in the last 1.5 decades by comparing advanced breeding clones (T4 upwards) bred in Sweden (Svensk potatisförädling hereafter) versus available released cultivars in Europe and grown in its Nordic Region. The multi-site testing results show that potato breeding based in Scandinavia offers to the growers of the Nordic Region of Europe cultivars for prevailing farming environments and end-user needs rather than relying, as happens today in the market, on foreign cultivars. These cultivars bred elsewhere are not always very suitable for the challenging Nordic agroecosystems, as shown by the results of the multi-site testing herein. Such an approach on relying on foreign cultivars may be advocated for not funding potato breeding in, and for Fennoscandia by those ignoring the results shown by this research.

Breeding has increased genetic gain for dairy cattle in advanced economies but has had limited success in improving dairy cattle in low- to middle-income countries (LMIC). Genetic evaluations are a central component of delivering genetic gain, because they separate the genetic and environmental effects of animals’ phenotypes. Genetic evaluations have been successful in advanced economies because of large data sets and strong genetic connectedness, provided by the widespread use of artificial insemination (AI) and accurate recording of pedigree information. In smallholder dairy production systems of many LMICs, the limited use of AI and small herd sizes results in a data structure with insufficient genetic connectedness between herds to facilitate genetic evaluations based on pedigree. Genomic information keeps track of shared haplotypes rather than shared relatives captured by pedigree records. Therefore, genomic information could capture “hidden” genetic relationships, that are not captured by pedigree information, to strengthen genetic connected- ness in LMIC smallholder dairy data sets. This study’s objective was to use simulation to quantify the power of genomic information to enable genetic evaluation using LMIC smallholder dairy data sets. The results from this study show that (1) genetic evaluations using genomic information were more accurate than those using pedigree information in populations with a high effective population size and weak genetic connectedness; and (2) genetic evaluations modeling herd as a random effect had higher or equal accuracy than those mod- eling herd as a fixed effect. This demonstrates the potential of genomic information to be an enabling technology in LMIC smallholder dairy production systems by facilitating genetic evaluations with in situ records collected from herds of ≤4 cows. The establishment of routine genomic evaluations could allow the development of LMIC breeding programs comprising an informal set of nucleus animals distributed across many small herds within the target environment. These nucleus animals could be used for genetic evaluation, and the best animals could be disseminated to participating smallholder dairy farms. Together, this could increase the productivity, profitability, and sustainability of LMIC smallholder dairy production systems.

The growing global demand for wheat for food is rising due to the influence of population growth and climate change. The dissection of complex traits by employing a genome-wide association study (GWAS) allows the identification of DNA markers associated with complex traits to improve the productivity of crops. We used GWAS with 10,045 single nucleotide polymorphism (SNP) markers to search for genomic regions associated with grain yield and related traits based on diverse panels of Ethiopian durum wheat. In Ethiopia, multi-environment trials of the genotypes were carried out at five locations. The genotyping was conducted using the 25k Illumina Wheat SNP array to explore population structure, linkage disequilibrium (LD), and marker-trait associations (MTAs). For GWAS, the multi-locus Fixed and Random Model Circulating Probability Unification (FarmCPU) model was applied. Broad-sense heritability estimates were high, ranging from 0.63 (for grain yield) to 0.97 (for thousand-kernel weight). The population structure based on principal component analysis, and model-based cluster analysis revealed two genetically distinct clusters with limited admixtures. The LD among SNPs declined within the range of 2.02–10.04 Mbp with an average of 4.28 Mbp. The GWAS scan based on the mean performance of the genotypes across the environments identified 44 significant MTAs across the chromosomes. Twenty-six of these MTAs are novel, whereas the remaining 18 were previously reported and confirmed in this study. We also identified candidate genes for the novel loci potentially regulating the traits. Hence, this study highlights the significance of the Ethiopian durum wheat gene pool for improving durum wheat globally. Furthermore, a breeding strategy focusing on accumulating favorable alleles at these loci could improve durum wheat production in the East African highlands and elsewhere.

The wild species field cress (Lepidium campestre) has the potential to become a novel cover and oilseed crop for the Nordic climate. Its seed oil is however currently unsuitable for most food, feed, and industrial applications, due to the high contents of polyunsaturated fatty acids (PUFAs) and erucic acid (C22:1). As the biosynthesis of these undesirable fatty acids is controlled by a few well-known major dominant genes, knockout of these genes using CRISPR/Cas9 would thus be more effective in improving the seed oil quality. In order to increase the level of the desirable oleic acid (C18:1), and reduce the contents of PUFAs and C22:1, we targeted three important genes FATTY ACID ELONGASE1 (FAE1), FATTY ACID DESATURASE2 (FAD2), and REDUCED OLEATE DESATURASE1 (ROD1) using a protoplast-based CRISPR/Cas9 gene knockout system. By knocking out FAE1, we obtained a mutated line with almost no C22:1, but an increase in C18:1 to 30% compared with 13% in the wild type. Knocking out ROD1 resulted in an increase of C18:1 to 23%, and a moderate, but significant, reduction of PUFAs. Knockout of FAD2, in combination with heterozygous FAE1fae1 genotype, resulted in mutated lines with up to 66% C18:1, very low contents of PUFAs, and a significant reduction of C22:1. Our results clearly show the potential of CRISPR/Cas9 for rapid trait improvement of field cress which would speed up its domestication process. The mutated lines produced in this study can be used for further breeding to develop field cress into a viable crop.

Paddy rice cultivation contributes to global warming by emitting methane into the atmosphere. The aims of the work presented in this thesis were to breed climatefriendly rice varieties, to increase rice straw utilisation to reduce the impact of rice cultivation on the environment. The results showed that fumarate and ethanol were the two major exudate compounds from SUSIBA2-rice roots regulating methane emissions from SUSIBA2-rice paddies. A naturally occurring low-methane rice variety was identified and field testing demonstrated that it could be successfully grown in Uppsala, Sweden, opening up possibilities for expanding rice cultivation into high-latitude countries. Key candidate genes important in adaptation of rice to Scandinavian light and climate conditions were identified. By crossing a naturally occurring low-methane rice variety with four high-yielding elite varieties, four independent lines of low-methane rice with high yield potential were developed. Field trials demonstrated that methane emissions from the selected lines were reduced by 70%. Analysis of carbon allocation and molecular analyses of gene activities revealed that sugar transporters such as SUT and SWEET participated in allocation of carbon to aboveground tissues, contributing to the high yield and lowmethane properties. The results also indicated that increasing the lipid content in rice straw could increase its value in bioenergy production. Overall, this thesis shows that plant breeding can successfully address several pressing issues affecting sustainability in rice production by reducing greenhouse gas emissions, increasing crop productivity and diversity, and improving bioenergy production from straw.

Background An understanding of farmers' preferences of new banana cultivars and their characteristics is critical for developing and selecting cultivars that meet consumer needs. Therefore, phenotypic selection in a genetically variable population remains an important aspect of plant breeding. Methods The participatory varietal selection approach for preference ranking was used on 31 'Matooke' secondary and primary triploid hybrids and local banana cultivars evaluated between 2016 and 2019 in Uganda and Tanzania to investigate how farmers' preference attributes could help breeders identify superior cultivars. The quantitative data were analyzed using the Statistical Package for Social Sciences (SPSS). The qualitative data from farmers' focus group discussions (FGDs) were described using content analysis. The Mann–Whitney U test and Wilcoxon's signed-rank test were used to confirm the difference in farmers' preferences between groups. Results Farmers' approaches for defining characteristics were multivariate, and their preferences varied by site and country. Large fruit, a large bunch, market acceptability of the banana bunch, a sturdy stem, and an attractive appearance of the banana plant were the characteristics most preferred by farmers in Tanzania and Uganda. Tanzanian farmers preferred large bunches over other characteristics like bunch marketability and robust stem. Large fruit, drought tolerance, a strong stem, and phenotypic similarity to local cultivars were prioritized by Ugandan farmers. Both men and women farmers were more concerned with production-related characteristics, but the former valued marketing-related characteristics more, while the latter preferred use-related characteristics. Their preferences did not differ statistically, but the relative importance assigned by each group to the selected attributes was different. Conclusion Farmers' varietal preferences are frequently based on some assumed requirements, resulting in cultivar rejection or non-adoption. Therefore, determining the value attributed to each characteristic by various farmer groups is crucial in developing 'Matooke' banana cultivars with desired attributes that will boost the rate of adoption on-farms. Breeding initiatives that establish a system of integrated approaches and rely on thorough diagnosis of both production and consumption characteristics will best serve farmers' diverse preferences. To accomplish this, planning for varietal improvement initiatives at various levels—including internationally, regionally, nationally, and locally—would require a strong participatory structure that is gender inclusive.

Background: International evaluations combine data from different countries allowing breeders to have access to larger panels of elite bulls and to increase the accuracy of estimated breeding values (EBV). However, international and national evaluations can use different sources of information to compute EBV (EBVINT and EBVNAT, respectively), leading to differences between them. Choosing one of these EBV results in losing the information that is contained only in the discarded EBV. Our objectives were to define and validate a procedure to integrate publishable sires’ EBVINT and their associated reliabilities computed from pedigree-based or single-step international beef cattle evaluations into national evaluations to obtain “blended” EBV. The Italian (ITA) pedigree-based national evaluation was used as a case study to validate the integration procedure. Methods: Publishable sires’ international information, i.e. EBVINT and their associated reliabilities, was included in the national evaluation as pseudo-records. Data were available for 444,199 individual age-adjusted weaning weights of Limousin cattle from eight countries and 17,607 genotypes from four countries (ITA excluded). To mimic differences between international and national evaluations, international evaluations included phenotypes (and genotypes) of animals born prior to January 2019, while national evaluations included ITA phenotypes of animals born until April 2019. International evaluations using all available information were considered as reference scenarios. Publishable sires were divided into three groups: sires with ≥ 15, < 15 and no recorded offspring in ITA. Results: Overall, for these three groups, integrating either pedigree-based or single-step international information into national pedigree-based evaluations improved the similarity of the blended EBV with the reference EBV compared to national evaluations without integration. For instance, the correlation with the reference EBV for direct (maternal) EBV went from 0.61 (0.79) for a national evaluation without integration to 0.97 (0.88) when integrating single-step international information, on average across all groups of publishable sires. Conclusions: Our proposed one-animal-at-a-time integration procedure yields blended EBV that are in close agreement with full international EBV for all groups of animals analysed. The procedure can be directly applied by countries since it does not rely on specific software and is computationally inexpensive, allowing straightforward integration of publishable sires’ EBVINT from pedigree-based or single-step based international beef cattle evaluations into national evaluations.

Det pågår en omställning av jord- och trädgårdsbruket, både med hänsyn till hållbar produktion och pågående klimatförändringar. Som en del av EUs arbete att utveckla lantbruket mot en mer hållbar produktion har kommissionen lagt fram ett förslag på minskning av växtskyddsmedel om minst 50 %, totalt sett inom EU, senast 2030. För Sveriges del innebär förslaget, enligt preliminära beräkningar, att vi behöver minska mängden växtskyddsmedel med 35-36 %. För att ersätta funktionen av denna mängd växtskyddsmedel behövs ett integrerat tillvägagångssätt som kräver tillgång till andra effektiva metoder för bekämpning av skadegörare på odlade växter.Under det senaste decenniet har nya genomiska tekniker inom växtförädlingen utvecklats, vilka möjliggör riktade förändringar i många grödors genom. Teknikerna innebär antingen att man introducerar enstaka förändringar i DNA-sekvensen (s.k. genomredigering), eller att man sätter in en längre DNA-sekvens från samma art eller en korsningsbar art i en gröda (s.k. cisgenes). Dessutom har kunskapen om växters försvarssystem framskridit avsevärt. Med den ökade kunskapen och de nya teknikerna ökar möjligheten att kombinera gener och öka variationen av de gener som gör grödorna resistenta mot olika växtsjukdomar. På så sätt kan förädlingen av sjukdomsresistenta sorter ske med betydligt bättre precision och på kortare tid än vad traditionella förädlingstekniker tillåter. Tidsaspekten kan ses som extra viktig i resistenssammanhang eftersom skadegörarpopulationerna ändras kontinuerligt. Potentialen att kombinera flera olika resistensmekanismer för att uppnå mer uthållig resistens samt möjligheten att lösa ett eller flera växtskyddsproblem i samma sort bör också noteras.Enligt nuvarande EU-lagstiftning regleras dock genomredigerade och cisgena grödor på samma sätt som traditionellt genetiskt modifierade organismer (GMO), en lagstiftning som i praktiken omöjliggör kommersiell odling inom EU. Detta trots att resultatet av de moderna teknikerna kan efterlikna vad som kan ske spontant i naturen (mutationer) eller via traditionella oreglerade förädlingsmetoder (t.ex. mutations-, eller korsningsförädling). I lagstiftningen tas det ej i beaktande att sjukdomsresistenta grödor kan bidra till en minskad användning av växtskyddsmedel.Idag är potatisodling ofta förknippad med en användning av stora mängder växtskyddsmedel mot potatisbladmögel. Samtidigt är det möjligt att göra potatissorterna helt resistenta mot potatisbladmögel med hjälp av cisgenes och ge dem en ökad motståndskraft med hjälp av genomredigering. Om det vore möjligt att odla potatis som förädlats med nya genomiska tekniker inom EU idag, visar denna rapport att det skulle vara möjligt att kraftigt minska användningen av växtskyddsmedel i potatisodlingen. Det skulle innebära en reducering av mängden växtskyddsmedel som används inom det svenska lantbruket och skulle även innebära besparingar runt 91 miljoner SEK per år för odlarna.Vete och annan spannmål är de grödor där flest totala hektardoser av fungicider appliceras, till en årlig kostnad av två miljarder SEK. För dessa grödor finns inget lika tydligt exempel på enskilda sjukdomar som så kraftigt kan minska fungicidanvändningen. Vi ser dock en tydlig framtida potential att minska antalet bekämpningar och därmed kostnaden för lantbruket med hjälp av nya genomiska tekniker inom sädesslagen.Möjligheten att öka växters egen resistens för att minska användningen av växtskyddsmedel finns redan idag även i flera andra grödor, och möjligheterna förväntas fortsatt växa i takt med att teknikutveckling och forskning fortgår. En förändrad lagstiftning runt nya genomiska tekniker skulle även öppna för applikationer inom områden där det idag inte finns någon effektiv metod att bekämpa växtskadegörare. Exempel på sådana skadegörare är många virussjukdomar och skador som orsakas av nematoder. Därför kan skördestabiliteten och konkurrenskraften förväntas öka i grödor där det idag finns skadegörare där effektiva bekämpningsmetoder saknas.Sammanfattningsvis ser vi nya genomiska tekniker för att förädla resistenta grödor som en viktig del i arbetet mot ett hållbart jordbruk och för att uppnå EU-kommissionens mål om att reducera användningen av växtskyddsmedel inom jord- och trädgårdsbruket.

It is of paramount importance in plant breeding to have methods dealing with large numbers of predictor variables and few sample observations, as well as efficient methods for dealing with high correlation in predictors and measured traits. This paper explores in terms of prediction performance the partial least squares (PLS) method under uni-trait (UT) and multi-trait (MT) prediction of potato traits. The first prediction was for tested lines in tested environments under a five-fold cross-validation (5FCV) strategy and the second prediction was for tested lines in untested environments (herein denoted as leave one environment out cross validation, LOEO). There was a good performance in terms of predictions (with accuracy mostly > 0.5 for Pearson’s correlation) the accuracy of 5FCV was better than LOEO. Hence, we have empirical evidence that the UT and MT PLS framework is a very valuable tool for prediction in the context of potato breeding data

Background Wood represents the majority of the biomass on land and constitutes a renewable source of biofuels and other bioproducts. However, wood is recalcitrant to bioconversion, raising a need for feedstock improvement in production of, for instance, biofuels. We investigated the properties of wood that affect bioconversion, as well as the underlying genetics, to help identify superior tree feedstocks for biorefining. Results We recorded 65 wood-related and growth traits in a population of 113 natural aspen genotypes from Sweden (https://doi.org/10.5061/dryad.gtht76hrd). These traits included three growth and field performance traits, 20 traits for wood chemical composition, 17 traits for wood anatomy and structure, and 25 wood saccharification traits as indicators of bioconversion potential. Glucose release after saccharification with acidic pretreatment correlated positively with tree stem height and diameter and the carbohydrate content of the wood, and negatively with the content of lignin and the hemicellulose sugar units. Most of these traits displayed extensive natural variation within the aspen population and high broad-sense heritability, supporting their potential in genetic improvement of feedstocks towards improved bioconversion. Finally, a genome-wide association study (GWAS) revealed 13 genetic loci for saccharification yield (on a whole-tree-biomass basis), with six of them intersecting with associations for either height or stem diameter of the trees. Conclusions The simple growth traits of stem height and diameter were identified as good predictors of wood saccharification yield in aspen trees. GWAS elucidated the underlying genetics, revealing putative genetic markers for bioconversion of bioenergy tree feedstocks.

Drought stress is a major production constraint in crops globally. Crop wild relatives are important sources of resistance and tolerance for both biotic and abiotic stresses, respectively. A breeding program was initiated to introgress drought tolerance in sunflowers through hybridization between the wild species Helianthus argophyllus and the cultivated pool of H. annuus. Selection was carried out from the F2 to F5 segregating populations for the silver canopy, high cuticular wax, small leaf area, single heading and high oil content. Cuticular wax ranged between 8.72 µg g−1 and 17.19 µg g−1 in the F5 offspring. The selected F5 breeding lines were self-pollinated to obtain the F6 generation. Thereafter, this F6 was compared with the non-adapted elite sunflower germplasm in a factorial complete randomized design with different water treatments; i.e., comparing fully irrigated (100%, T0) versus 75% (T1), 50% (T2) and 25% (T3) of total irrigation. The comparison between the two types of the germplasm showed that drought-tolerant breeding lines had a comparatively lesser decrease in leaf area (0, 11, 22%) and shoot length (4, 21, 28%) than the elite germplasm, which experienced a decrease in leaf area (21%, 33% and 40%) and shoot length (17, 27 and 34%) under the various drought treatments. Moreover, drought-tolerant breeding lines had 100% more root shoot ratios than the elite germplasm (20%) in T3 when compared with control. Several drought-tolerant promising lines (D-2, D-5 and D-27) were selected due to their high leaf area, great root length and increased root to shoot ratio under T3. Some of the lines could be directly used for the development of drought-tolerant hybrids. Combining ability testing indicated that D-27 (F7) was a good general combiner for seed yield plant−1 and oil content after mating with male-line RSIN.82. Resulting hybrids could help to minimize seed yield loss due to water stress and to achieve profitable cultivation of sunflowers in arid regions of Pakistan.

Wheat is considered an established crop with a long breeding history. Its varieties are being developed with differential breeding targets, e.g. high grain yield or high grain protein content. The different breeding targets strongly influence performance in the targeted traits, but may also influence non-target traits related to grain quality, biofortification potential, and nutrient accumulation. This influence of non-targeted traits may, in turn, affect the environmental performance and ecological sustainability of the crop. The aim of this study was to evaluate the relationships between breeding target traits such as grain yield and grain quality, and non-target traits for three groups of spring wheat varieties differing in breeding targets, i.e. high yield (I), organic high protein (II), and intermediate (III) wheat types. Data from a field trial with nine spring wheat varieties grown under two soil compaction treatments over two years with contrasting weather were used. We found that wheat type affected most target and non-target traits with partly large effect sizes (0.874≤ηp 2≤0.173), but not nitrogen (N) uptake efficiency ( ηp 2=0.006), which reflects the potential N resource requirement of the crop. Associations shown between target and non-target traits will be advantageous for wheat breeding programs. Wheat type and environment had similarly sized effects on grain yield and quality traits. Grain concentrations of various macro- and micro-nutrients were frequently, but not always, correlated, indicating that the biofortification potential varied between wheat types and was affected by environmental conditions. The grain and starch yields per accumulated plant N were higher in the wheat varieties bred for high grain yields than those bred for high grain protein content; whilst the protein yield per accumulated whole-plant N was similar across all wheat types despite much higher grain N concentrations in the high-protein varieties. Additionally, most of the evaluated traits tended to preserve their static stability across environments. The results link grain yield and grain quality traits to crop nutrient accumulation aspects relevant for the environmental performance and ecological sustainability of the crop. Future breeding strategies should consider the non-target effects in traits that influence the environmental performance of the crop.

International audience; Bernese mountain dogs are a large dog breed formed in the early 1900s in Switzerland. While originally farm dogs that were used for pulling carts, guarding, and driving cattle, today they are considered multi-purpose companion and family dogs. The breed is predisposed to several complex diseases, such as histiocytic sarcoma, degenerative myelopathy, or hip dysplasia. Using whole-genome sequencing (WGS) data, we assessed the genomic architecture of 33 unrelated dogs from four countries: France, Sweden, Switzerland, and the United States. Analysis of runs of homozygosity (ROH) identified 12,643 ROH with an average length of 2.29 Mb and an average inbreeding coefficient of 0.395. Multidimensional scaling analysis of the genetic relatedness revealed limited clustering of European versus USA dogs, suggesting exchanges of breeding stock between continents. Furthermore, only two mtDNA haplotypes were detected in the 33 studied dogs, both of which are widespread throughout multiple dog breeds. WGS-based ROH analyses revealed several fixed or nearly fixed regions harboring discreet morphological trait-associated as well as disease-associated genetic variants. Several genes involved in the regulation of immune cells were found in the ROH shared by all dogs, which is notable in the context of the breed’s strong predisposition to hematopoietic cancers. High levels of inbreeding and relatedness, strongly exaggerated in the last 30 years, have likely led to the high prevalence of specific genetic disorders in this breed.

Multi-environment trials (METs) of potato breeding clones and cultivars allow to precisely determine their performance across testing sites over years. However, these METs may be affected by the genotype × environment interaction (GEI) as noted in tuber yield. Furthermore, trials are replicated several times to optimize the predictive value of the data collected because knowledge on spatial and temporal variability of testing environments is often lacking. Hence, the objectives of this research were to use components of variance from METs to estimate broad sense heritability (H2) based on best linear unbiased predictors and use these estimates to determine the optimum number of sites, years, and replications for testing potato breeding clones along with cultivars. The data were taken from METs in southern and northern Sweden comprising up to 256 breeding clones and cultivars that underwent testing using a simple lattice design of 10-plant plots across three sites over 2 years. Percentage starch in the tuber flesh had the largest H2 in each testing environment (0.850–0.976) or across testing environments (0.905–0.921). Total tuber weight per plot also exhibited high H2 (0.720–0.919) in each testing environment or across them (0.726–0.852), despite a significant GEI. Reducing sugar content in the tuber flesh had the lowest, but still medium H2 (0.426–0.883 in each testing environment; 0.718–0.818 across testing environments). The H2 estimates were smaller when their variance components were disaggregated by year and site, instead of lumping them as environments. Simulating H2 with genetic, site, year, site × year, genetic × site, genetic × year, genetic × site × year, and residual variance components led to establish that two replicates at each of two sites in 2-year trials will suffice for testing tuber yield, starch and reducing sugars. This article provides a methodology to optimize the number of testing size and years for METs of potato breeding materials, as well as tabulated information for choosing the appropriate number of trials in same target population of environments.

In this study, we explored mating allocation in Hol-stein using genomic information for 24,333 Holstein fe-males born in Denmark, Finland, and Sweden. We used 2 data sets of bulls: the top 50 genotyped bulls and the top 25 polled genotyped bulls on the Nordic total merit scale. We used linear programming to optimize economic scores within each herd, considering genetic level, genetic relationship, semen cost, the economic impact of genetic defects, polledness, and 0-casein. We found that it was possible to reduce genetic relation-ships and eliminate expression of genetic defects with minimal effect on the genetic level in total merit index. Compared with maximizing only Nordic total merit in-dex, the relative frequency of polled offspring increased from 13.5 to 22.5%, and that of offspring homozygous for 0-casein (A2A2) from 66.7 to 75.0% in one genera-tion, without any substantial negative impact on other comparison criteria. Using only semen from polled bulls, which might become necessary if dehorning is banned, considerably reduced the genetic level. We also found that animals carrying the polled allele were less likely to be homozygous for 0-casein (A2A2) and more likely to be carriers of the genetic defect HH1. Hence, adding economic value to a monogenic trait in the economic score used for mating allocation sometimes negatively affected another monogenetic trait. We rec-ommend that the comparison criteria used in this study be monitored in a modern genomic mating program.

Powdery mildew (PM) of wheat caused by Blumeria graminis f. sp. tritici is among the most important wheat diseases, causing significant yield and quality losses in many countries worldwide. Considerable progress has been made in resistance breeding to mitigate powdery mildew. Genetic host resistance employs either race-specific (qualitative) resistance, race-non-specific (quantitative), or a combination of both. Over recent decades, efforts to identify host resistance traits to powdery mildew have led to the discovery of over 240 genes and quantitative trait loci (QTLs) across all 21 wheat chromosomes. Sources of PM resistance in wheat include landraces, synthetic, cultivated, and wild species. The resistance identified in various genetic resources is transferred to the elite genetic background of a well-adapted cultivar with minimum linkage drag using advanced breeding and selection approaches. In this effort, wheat landraces have emerged as an important source of allelic and genetic diversity, which is highly valuable for developing new PM-resistant cultivars. However, most landraces have not been characterized for PM resistance, limiting their use in breeding programs. PM resistance is a polygenic trait; therefore, the degree of such resistance is mostly influenced by environmental conditions. Another challenge in breeding for PM resistance has been the lack of consistent disease pressure in multi-environment trials, which compromises phenotypic selection efficiency. It is therefore imperative to complement conventional breeding technologies with molecular breeding to improve selection efficiency. High-throughput genotyping techniques, based on chip array or sequencing, have increased the capacity to identify the genetic basis of PM resistance. However, developing PM-resistant cultivars is still challenging, and there is a need to harness the potential of new approaches to accelerate breeding progress. The main objective of this review is to describe the status of breeding for powdery mildew resistance, as well as the latest discoveries that offer novel ways to achieve durable PM resistance. Major topics discussed in the review include the genetic basis of PM resistance in wheat, available genetic resources for race-specific and adult-plant resistance to PM, important gene banks, and conventional and complimentary molecular breeding approaches, with an emphasis on marker-assisted selection (MAS).

Six cross-bred barley lines developed by a breeding strategy with the target to enhance the fructan synthesis activity and reduce the fructan hydrolysis activity were analyzed together with their parental lines, and a reference line (Gustav) to determine whether the breeding strategy also affected the content and molecular structure of amylopectin and beta-glucan. The highest fructan and beta-glucan content achieved in the novel barley lines was 8.6 % and 12 %, respectively (12.3-fold and 3.2-fold higher than in Gustav). The lines with low fructan synthesis activity had higher starch content, smaller building blocks in amylopectin, and smaller structural units of beta-glucans than the lines with high-fructan synthesis activity. Correlation analysis confirmed that low starch content was associated with high amylose, fructan, and beta-glucan content, and larger building blocks in amylopectin.

Hållbar utveckling handlar om att värna och nyttja de resurser vi har på ett sätt som gör att dagens behov uppfylls utan negativ påverkan på framtida generationers möjlighet att uppfylla sina behov. Samtliga tre dimensioner av hållbarhet - ekologisk, ekonomisk och social - behöver inkluderas. I ett hållbart växtskyddsarbete eftersträvas en minimerad förlust av skörden på grund av skadegörare och ogräs med en så liten negativ påverkan av insatserna som möjligt på människor, djur och miljö, samtidigt som produktionen bedrivs konkurrenskraftigt, lönsamt och säkert ur ett arbetsmiljöperspektiv. År 2022 publicerades en kunskapssammanställning om hållbara odlingssystem med avseende på växtskydd (Lundin och Friberg, 2022). Där konstaterades att det vore av stort värde om fler indikatorer för hållbart växtskydd kunde utvecklas, för att vi i framtiden ska kunna skatta hållbarheten utifrån fler dimensioner än vad som görs idag. Den belyste också behovet av en utökad ekonomisk analys av hållbarhet kopplat till skördebortfall och till diversifiering genom val av olika grödor i växtodlingen. Den här rapporten bygger vidare på kunskapssammanställningens slutsatser genom en fördjupad diskussion om hur nya indikatorer som speglar utveckling av skadegörare, de skador de orsakar samt resistensutveckling kan användas för att skatta hållbarheten i svensk växtproduktion. Rapporten presenterar också ekonomiska analyser utifrån bekämpningskostnader och skördebortfall, samt ekonomiska aspekter på ökad diversifiering genom ökad odlad mångfald.Baserat på vårt arbete föreslår vi att skadegörardata som sedan 1989 samlats in via Jordbruksverkets växtskyddscentraler används för indikatorer för skadegörare i jordbruksgrödor, och presenterar i rapporten ett förslag på urval av 16 viktiga skadegörare samt en modell för att följa deras förekomst över tid. Eftersom bakomliggande data finns sammanställda och tillgängliggjorda kan en sådan indikator tillämpas redan i dagsläget. En indikator för skördebortfall orsakat av skadegörare kan utvecklas genom att bearbeta data från de bekämpningsförsök som årligen genomförs, och rapporten presenterar en modell för hur en sådan indikator kan beräknas utifrån dessa försöksdata. Till skillnad från indikatorerna för skadegörarförekomst finns inte data från bekämpningsförsök sammanställda och tillgängliggjorda i dagsläget, utan kräver avsevärd bearbetning innan en sådan indikator kan beräknas. Vi anser det därför angeläget att en sådan sammanställning görs, så att även en indikator för skördeförluster kan användas. Bekämpningsförsöken är också begränsade avseende vilka grödor och skadegörare som finns tillräckligt representerade. Vi ser de försök som avser sjukdomar i höstvete och vårkorn som mest lämpliga för utvecklingen av framtida indikatorer, medan liknande försök för skadeinsekter i dagsläget är alltför få för att utgöra en säker grund till motsvarande beräkningar. Vi föreslår också att de resistenstester som genomförs för herbicider, fungicider och insekticider i Sverige sammanfattas till en indikator för resistensutvecklingen som speglar växtskyddets evolutionära hållbarhet.Ekonomiska beräkningar som gjordes utifrån bekämpningsförsök i höstvete och vårkorn visade på stor skillnad i lönsamhet vid kemisk bekämpning av sjukdomar orsakade av svampar för år med högt sjukdomstryck jämfört med år med lågt sjukdomstryck. Resultaten belyser vikten av god precision och säkerhet i prognoser och beslutsstöd kring kemisk bekämpning för en god behovsanpassning av bekämpningen.Diversifiering genom en ökad mångfald av odlade grödor kan både minska lantbruksföretagets risk och öka lantbruksföretagets lönsamhet när diversifiering sker med tillräckligt lönsamma grödor. För att gynna en diversifiering kan det vara effektivt att ha ekonomiskt stöd direkt kopplat till grödan, i de fall där det finns befintliga avsättningsmöjligheter i stor skala. När avsättningsmöjligheterna behöver förbättras kan stöd ges för att vidareförädla grödan. Dessutom kan det behövas hjälp med organisation och kunskap kring nya grödor. Därmed kan det vara lämpligt med olika stödutformning för olika situationer där olika stöd kan komplettera varandra.

Commercial fruit production in Norway is located at around latitude 60° north, demanding a careful choice of adapted cultivars. The most comprehensive collection of apple genetic resources in Norway is being kept in the Norwegian Apple Collection (NAC) at the Njøs Fruit and Berry Centre (NJØS). The collection contains around 350 accessions and was recently genotyped with a single nucleotide polymorphism (SNP) array. Curated SNP data were used for the assessment of structure and diversity, pedigree confirmation, and core collection development. In the following SNP analysis, we identified several duplicates and parent-child relationships. Across the geographic regions represented, the collection was equally diverse. Different methods for analyzing population structure were applied. K-means clustering and a Bayesian modeling approach with prior assumptions of the data revealed five subpopulations associated with geographic breeding centers. The collection has a distinct genetic structure and low relatedness among the accessions; hence, two core collections with 100 accessions in each were created. These new core collections will allow breeders and researchers to use the NAC efficiently. The results from this study suggest that several of the accessions in the Norwegian Apple Collection could be of high importance for breeding purposes.

Finger millet (Eleusine coracana (L.) Gaertn.) is an annual allotetraploid that belongs to the grass family Poaceae subfamily Chloridoideae. Using less productive cultivars, biotic and abiotic stresses affect the yield and productivity of finger millet in Ethiopia. This research was aimed at investigating the acidity/Al tolerance of 328 finger millet accessions and 15 cultivars from Ethiopia and Zimbabwe. Prior to screening the accessions, optimization was performed on 15 cultivars and 15 accessions under three Al concentrations (0, 75, and 100 µM), and, afterward, 100 µM of Al concentration was selected as the threshold level. Root length (RL) and shoot length (SL) were recorded after 10 days of treatment. Accessions 215836, 215845, and 229722 and cultivars Urji, Bareda, and Axum were found Al-tolerant, while cultivars Tadesse, Padet, and Kumsa and accessions 212462, 215804, and 238323 were found Al-susceptible. ANOVA on RL indicated that the variance due to environment (42.3) was higher than genotypic variance (0.37). Whereas, the ANOVA on SL indicated the variance due to environment was not significant, and genotypic variance (0.18) was higher than environmental (0.02). RL was highly affected due to Al stress, while no distinct and visible symptoms were observed on SL. Furthermore, the screening of 328 accessions under 100 µM and the control resulted in Al-tolerant (n = 20), intermediate (225), and Al-susceptible (83). The results of the present study reveal that the presence of acid-tolerant accessions can be used as inputs for breeders to improve the productivity of finger millet in acidic areas.

In this study, we extend research on genomic prediction (GP) to polysomic polyploid plant species with the main objective to investigate single-trait (ST) and multitrait (MT) multienvironment (ME) models using field trial data from 3 locations in Sweden [Helgegården (HEL), Mosslunda (MOS), Umeå (UM)] over 2 years (2020, 2021) of 253 potato cultivars and breeding clones for 5 tuber weight traits and 2 tuber flesh quality characteristics. This research investigated the GP of 4 genome-based prediction models with genotype × environment interactions (GEs): (1) ST reaction norm model (M1), (2) ST model considering covariances between environments (M2), (3) ST M2 extended to include a random vector that utilizes the environmental covariances (M3), and (4) MT model with GE (M4). Several prediction problems were analyzed for each of the GP accuracy of the 4 models. Results of the prediction of traits in HEL, the high yield potential testing site in 2021, show that the best-predicted traits were tuber flesh starch (%), weight of tuber above 60 or below 40 mm in size, and the total tuber weight. In terms of GP, accuracy model M4 gave the best prediction accuracy in 3 traits, namely tuber weight of 40–50 or above 60 mm in size, and total tuber weight, and very similar in the starch trait. For MOS in 2021, the best predictive traits were starch, weight of tubers above 60, 50–60, or below 40 mm in size, and the total tuber weight. MT model M4 was the best GP model based on its accuracy when some cultivars are observed in some traits. For the GP accuracy of traits in UM in 2021, the best predictive traits were the weight of tubers above 60, 50–60, or below 40 mm in size, and the best model was MT M4, followed by models ST M3 and M2.

Intercropping, also known as mixed cropping, consists on simultaneously growingmore than one species on a field. It has a great potential for enhancing water- and nutrientuseefficiency and improving plant productivity, yield stability and resilience to biotic and abiotic stress, including those triggered by climate change. Despite their manifold benefits,the practice of intercropping has not risen above its niche status in many regions of theworld. The selection of varieties specifically adapted to intercropping remains a major practical challenge to its widespread deployment. This Editorial of a Research Topic hosted at Frontiersin Plant Sciences entitled “Breeding for intercropping” gathers a series of articles coveringnew insights in the areas of quantitative genetics, ecology, ecophysiology and agronomyintegrating theoretical, experimental as well as participatory approaches.