RESUMEN
Europe is highly dependent on soybean meal imports and anticipates an increase of domestic plant protein production. Ongoing climate change resulted in northward shift of plant hardiness zones, enabling spring-sowing of freezing-sensitive crops, including soybean. However, it requires efficient reselection of germplasm adapted to relatively short growing season and long-day photoperiod. In the present study, a PCR array has been implemented, targeting early maturity (E1-E4, E7, E9, and E10), pod shattering (qPHD1), and growth determination (Dt1) genes. This array was optimized for routine screening of soybean diversity panel (204 accessions), subjected to the 2018-2020 survey of phenology, morphology, and yield-related traits in a potential cultivation region in Poland. High broad-sense heritability (0.84-0.88) was observed for plant height, thousand grain weight, maturity date, and the first pod height. Significant positive correlations were identified between the number of seeds and pods per plant, between these two traits and seed yield per plant as well as between flowering, maturity, plant height, and first pod height. PCR array genotyping revealed high genetic diversity, yielding 98 allelic combinations. The most remarkable correlations were identified between flowering and E7 or E1, between maturity and E4 or E7 and between plant height and Dt1 or E4. The study demonstrated high applicability of this PCR array for molecular selection of soybean towards adaptation to Central Europe, designating recessive qPHD1 and dominant Dt1, E3, and E4 alleles as major targets to align soybean growth season requirements with the length of the frost-free period, improve plant performance, and increase yield.
RESUMEN
First pod height (FPH) is a quantitative trait in soybean [Glycine max (L.) Merr.] that affects mechanized harvesting. A compatible combination of the FPH and the mechanized harvester is required to ensure that the soybean is efficiently harvested. In this study, 147 recombinant inbred lines, which were derived from a cross between 'Dongnong594' and 'Charleston' over 8 years, were used to identify the major quantitative trait loci (QTLs) associated with FPH. Using a composite interval mapping method with WinQTLCart (version 2.5), 11 major QTLs were identified. They were distributed on five soybean chromosomes, and 90 pairs of QTLs showed significant epistatic associates with FPH. Of these, 3 were main QTL × main QTL interactions, and 12 were main QTL × non-main QTL interactions. A KEGG gene annotation of the 11 major QTL intervals revealed 8 candidate genes related to plant growth, appearing in the pathways K14486 (auxin response factor 9), K14498 (serine/threonine-protein kinase), and K13946 (transmembrane amino acid transporter family protein), and 7 candidate genes had high expression levels in the soybean stems. These results will aid in building a foundation for the fine mapping of the QTLs related to FPH and marker-assisted selection for breeding in soybean.