Genomic-based breeding technology for the improvement of pre-harvest sprouting resistance in spring wheat under Norwegian climate

Increasing wheat production for food is an important element to achieve the Norwegian government goal to increase the national food production. All wheat varieties in the Norwegian market today have the genetic potential needed for good baking quality, but this quality is often destroyed by pre-harvest sprouting (PHS) due to delayed harvest due to rain. Insufficient resistance to PHS is the main reason for downgrading of wheat to feed both in Norway and neighboring countries with similar climate, and affect farmers, and thus cause huge economic losses. SproutResist project has formally started in January 1, 2021 and will run until Dec 31, 2024. The project will be carried out via a collaboration between the industry partners Graminor AS and Strand Unikorn SA, and the research institutions NMBU, NOFIMA and UiO, and international research institutions in Germany, USA, and China. The primary objective of SproutResist project is to implement genomic-based breeding technology in the wheat breeding program at Graminor to develop wheat varieties with better resistance against PHS. This main objective will be reached through several secondary objectives; (i) Deeper understanding of the molecular basis of PHS resistance in wheat. (ii) Develop and test Genome Selection (GS) models where environment and significant genetic markers are incorporated. (iii) Implementation pipeline for DNA-based technologies (MAS and GS) for PHS resistance in the Graminor wheat breeding. The project also designates specific working package to develop strategies for MAS and GS in breeding programs to ensure return value. Several materials were tested in field trials in the 2021 season, at two locations in southeastern Norway with contrasting growing environments: Vollebekk research station in Ås and Staur research farm in Stange. As evaluation methods we rely on germination index (GI) to assess the degree of seed dormancy and falling number (FN) to assess the degree of sprouting damage when wheat plants have been exposed to rain before harvest. In some dedicated field trials, we also apply mist irrigation after maturity to provoke sprouting. Our association mapping panel of 300 spring wheat lines (MASBASIS) was evaluated at both locations together with approximately 300 new spring wheat breeding lines from Graminor. At Vollebekk, samples were taken from a subset of the new breeding lines for evaluation of GI, while FN will be measured on the grain samples from the trials at Staur. In addition, two mapping populations were evaluated for both FN (both Vollebekk and Staur) and GI (Vollebekk only) to provide data for QTL mapping. The two populations were also tested for GI under the higher grain filling temperature in Chengdu, China by our Chinese collaborators. Data from 296 lines from EXPAND project have been utilized to study 30 different environmental descriptors and their effect on PHS. Project partners have initiated work to establish a pipeline between data of farmers and the project. (Strand Unikorn will collect data from a selected group of farmers on which variety was used on which lots. Environmental data will be obtained for these lots. The aim is to include this information in the genetic evaluations.) 440 advanced breeding lines was genotyped with the Illumina 25K SNP Chip at SGS Trait Genetics. Offspring of crosses with lines harboring interesting QTL detected in EXPAND project period have been in field trials at Vollebekk and Staur to validate these QTL and linked markers.

Manglende resistens mot aksgroing er den viktigste årsaken til nedklassifisering av hvete til fôr i Norge og våre naboland med lignende klima, og påfører bøndene, møllene og bakeindustrien store økonomiske tap. Med et ustabilt klima med lengre perioder med regn om høsten, er det helt nødvendig å utvikle hvetesorter med bedre resistens mot aksgroing. Aksgroing er en svært komplisert egenskap, påvirket av både genetiske og miljømessige faktorer, noe som gjør foredlingen av aksgroingsresistente hvetesorter utfordrende. Graminor har de siste årene investert mye i flere genomikk- og teknologidrevne forskningsprosjekter, inkludert genomsekvensering, markørteknologi og genomisk seleksjon. Disse teknologiene er svært verdifulle i arbeidet med komplekse egenskaper. SproutResist prosjektet vil fortsette hovedambisjonen til det foregående prosjektet EXPAND (NFR # 256370); å utvikle verktøy og strategier samt implementering av disse for foredling av hvetesorter med forbedret resistens mot aksgroing tilpasset norsk klima. Graminor vil utnytte kunnskapen, teknologien og de molekylære verktøyene utviklet under EXPAND og tidligere teknologidrevne prosjekter: GenSel-prosjektet (NFR # 225181), Hvetegenomprosjekt (NFR # 199387) for å utvikle hvetesorter mer resistente mot aksgroing. Sammen med prosjektpartnere vil molekylære markører bli utviklet basert på genetiske studier av spiringsresistens i norsk hvete. Basert på resultater fra EXPAND prosjektet, vil mer komplekse genomseleksjonsmodeller utvikles. Disse modellene vil bli testet og validert på reelle data og implementert i Graminors hveteforedlingsprogram. Prosjektet vil lede fram til et hveteforedlingsprogram hos Graminor hvor markør- og genomseleksjonsteknologi er inkorporert. Dette vil føre til raskere genetisk fremgang i forbedring av aksgroingsresistens i norske hvetesorter, som vil resultere i et mer lønnsomt hveteforedlingsprogram hos Graminor.