Photoperiod sensitivity of soybean (Glycine max (L.) Merrill) limits its cultivation at high latitudes. Therefore, assessing the allelic composition of key genes E1–E4, which control flowering and maturation, is an important task for breeding programs. The aim of this study was to validate multiplex PCR for genotyping the E3 and E4 loci in comparison with the conventional approach of separate amplification, as well as to screen the allelic state of genes E1, E2, E3, and E4 in 11 soybean varieties of different ecogeographical origin cultivated in the Amur region. DNA was isolated from seeds using the DNA-Extran-3 kit. Genotyping was performed by PCR with allele-specific primers: for E3 and E4, the reaction was performed in both multiplex and separate formats, while for E1 and E2, only separate reactions were used. The E2 locus was analyzed using a CAPS marker after restriction with the Dral endonuclease. It was found that all studied varieties carry non-functional E1 alleles (e1-as or e1-fs); all varieties, except for Saska, carry the recessive (non-functional) e2-ns allele in a homozygous state, while Saska has only the dominant E2 variant. For the E3 gene, the E3-Ha (5 varieties) and e3-tr (6 varieties) alleles were detected; for the E4 gene, only the Hidaka variety contains the mutant allele e4-SORE, the others carry the functional E4. It was shown that multiplex PCR gives results that are completely consistent with separate amplification, while significantly reducing labor costs and reagent consumption. The greatest potential for early maturity was found in the Hidaka variety, which combines four non-functional alleles (e1-fs, e2-ns, e3-tr, e4-SORE). The obtained data can be used for targeted selection of parental forms in breeding for adaptation to long-day conditions.

Katrushenko Anastasiya A., Timkin Pavel D., Penzin Andrei A., Galichenko Anna P.

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