Agronomic, rheological and nutritional phenotypic data of 50 spelt varieties grown at 3 locations in Switzerland during 2 growing seasons (2021-2022)

This dataset contains agronomic, rheological, and nutritional parameters of 50 winter spelt varieties tested during 2 growing seasons (2021-2022) at 3 locations in Switzerland. The dataset has been used to investigate the links between genotype and phenotype of spelt varieties, published in https://doi.org/10.1007/s10681-024-03400-8. The field trials were performed under the Swiss Extenso (low input) conditions, conducted by Agroscope and DSP, and under organic conditions, performed by GZPK. Methods Field trials Field trials were set up over the course of two growing seasons – 2020/2021, 2021/2022 – in three sites across the Swiss Central Plateau. The experimental sites were located in Changins (46°19′ N 6°14′ E, 455m a.s.l), Delley (46°55′ N 6°58′ E, 494m a.s.l) and Feldbach (47°14'24.00" N, 8°47'9.60" E, 410m a.s.l.). Each variety was grown in a plot of 7.1 m2 (1.5 m*4.7 m) in Changins and Delley, and 4.5 m2 (1.5 m*3 m) in Feldbach. We replicated the experiment three times per location. At each site, we used a complete randomized block design, with plots being randomized within each block. Density of sowing was 180 spikelets/m2. Plots were sowed mechanically each autumn. In Changins and Delley, the plots were mechanically fertilized with 100 kg N/ha (ammonium nitrate), applied in two splits (60 at heading stage—40 at flowering stage). In Feldbach, the fields were treated organically, and therefore no synthetic fertilizer was applied. Agronomic and morphological characteristics For each plot, we recorded the heading date as the day of the year, in which 50% of the ears of the plot had fully emerged from the flag leaf. Once the plants and ears were fully developed, plant height was measured in each plot, by taking the average height in centimeters from the ground to the top of five random ears, excluding awns. At maturity, we harvested each plot with a combine harvester (Zürn 150, Schontal-Westernhausen, Switzerland). The harvested grains were weighed first, dehusked, sorted and cleaned with a sieve cleaner, and then weighted again. We measured specific weight and water content using a Dickey–John machine (GAC 2100). Grain yield was subsequently standardized to 15% of humidity. Protein content (%) was measured at the plot level with a near-infrared instrument (ProxiMate™, Büchi instruments). Thousand kernel weight (TKW, g), as well as kernel length and width (mm), were measured at the plot level with a Marvin seed analyzer (GTA Sensorik, Neubrandenburg, Germany). Additional measurements in Changins: we computed harvest index for each plot by cutting 30 individual culms just before harvest. Plants were cut just above the ground, oven-dried for 3 days at 80 °C and then weighed. We then threshed, dehusked, sieved and weighed the obtained grains. The harvest index was computed by taking the ratio of grain mass over total mass. Rheological characteristics At all sites, Zeleny sedimentation value (mL) was assessed based on the International Association for Cereal Science and Technology standard method 116/1.The analyses were performed by the analytical laboratory of DSP, Delley, at the variety level for each site—i.e., grains from the three replicates per site were pooled together and subsequently milled. Additional measurements in Changins were done for each variety, based on a pooled sample of the three replicates. Extensograph properties of the obtained dough were assessed according to ICC standard method 114/1; area under curve (energy, cm2), resistance to extension at 5 cm extension (EE), and extensibility of the dough (mm) were measured. The analyses were performed by the accredited laboratory “Versuchsanstalt für Getreideverarbeitung” based in Austria (https://www.vfg.or.at/). Nutritional characteristics We assessed the structure of starch (amylose content) and the fatty acid composition for each variety in Changins. These analyses were done by pooling grains from the three replicates in Changins and milling them. The amylose and amylopectin contents of starch were determined enzymatically via an assay based on the precipitation of amylopectin complexes with the lectin concanavalin A, according to K-Amy 06/18. The fatty acid composition was analyzed by GC-FAME, via in situ transesterification, according to the method of Ampuero Kragten et al. (2014). These analyses were performed at the accredited analytical laboratory of Agroscope, Posieux. Kragten SA, Collomb M, Dubois S, Stoll P (2014) Determination of fatty acid composition in feed: analytical methods. Agrarforschung Schweiz 5(9):330–337 DNA extraction & Genotyping DNA was extracted from all cultivars, and sent to TraitGenetics (SGS institute Frenius, Gatersleben DE) for SNP genotyping on the 25 K XT Infinium array for wheat.