Mapping of QTLs controlling epicotyl length in adzuki bean (Vigna angularis)

Masahiko Mori; Kento Maki; Tsubasa Kawahata; Daigo Kawahara; Yuta Kato; Toru Yoshida; Hidetaka Nagasawa; Hitoshi Sato; Atsushi J Nagano; Paul C Bethke; Kiyoaki Kato

doi:10.1270/jsbbs.20093

Mapping of QTLs controlling epicotyl length in adzuki bean (Vigna angularis)

Breed Sci. 2021 Apr;71(2):208-216. doi: 10.1270/jsbbs.20093. Epub 2021 Apr 7.

Authors

Masahiko Mori¹, Kento Maki¹, Tsubasa Kawahata¹, Daigo Kawahara¹, Yuta Kato¹, Toru Yoshida¹, Hidetaka Nagasawa², Hitoshi Sato^{2

3}, Atsushi J Nagano⁴, Paul C Bethke^{5

6}, Kiyoaki Kato¹

Affiliations

¹ Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
² Tokachi Agricultural Experiment Station, Agricultural Research Department, Hokkaido Research Organization, Memuro, Hokkaido 082-0081, Japan.
³ Plant Genetic Resources Division, Central Agricultural Experiment Station, Agricultural Research Department, Hokkaido Research Organization, Takikawa, Hokkaido 073-0013, Japan.
⁴ Faculty of Agriculture, Ryukoku University, Otsu, Shiga 520-2194, Japan.
⁵ Vegetable Crops Research Unit, USDA Agricultural Research Service, Madison, Wisconsin 53706, USA.
⁶ Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706, USA.

Abstract

Epicotyl length (ECL) of adzuki bean (Vigna angularis) affects the efficiency of mechanized weeding and harvest. The present study investigated the genetic factors controlling ECL. An F₂ population derived from a cross between the breeding line 'Tokei1121' (T1121, long epicotyls) and the cultivar 'Erimo167' (common epicotyls) was phenotyped for ECL and genotyped using simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP) markers. A molecular linkage map was generated and fifty-two segregating markers, including 27 SSRs and 25 SNPs, were located on seven linkage groups (LGs) at a LOD threshold value of 3.0. Four quantitative trait loci (QTLs) for ECL, with LOD scores of 4.0, 3.4, 4.8 and 6.4, were identified on LGs 2, 4, 7 and 10, respectively; together, these four QTLs accounted for 49.3% of the phenotypic variance. The segregation patterns observed in F₅ residual heterozygous lines at qECL10 revealed that a single recessive gene derived from T1121 contributed to the longer ECL phenotype. Using five insertion and deletion markers, this gene was fine mapped to a ~255 kb region near the end of LG10. These findings will facilitate marker-assisted selection for breeding in the adzuki bean and contribute to an understanding of the mechanisms associated with epicotyl elongation.

Keywords: InDel marker; QTL; RAD-seq; SNP marker; SSR marker; adzuki bean (Vigna angularis); epicotyl length.