Transgressive segregation of isoflavone contents under the control of four QTLs in a cross between distantly related soybean varieties

Abstract

Soybean (Glycine max (L) Merr.) isoflavones have attracted considerable attention for their diverse effects on human health. To determine the genetic factors that contribute to the high isoflavone contents of the soybean varieties 'Peking' and 'Tamahomare', we conducted QTL analyses for the total content of daidzein derivatives (DAC), genistein derivatives (GEC) and glycitein derivatives (GLC), and for the total content of isoflavones (TIC) using recombinant inbred lines (RILs) derived from the cross between 'Peking' and 'Tamahomare'. Ninety six RILs were planted in Kyoto, Osaka and Nagano in 2003 and in Osaka and Nagano in 2004. Transgressive segregation for TIC was detected in all the environments tested. Composite interval mapping for TIC revealed four QTLs: qIso1, qIso2, qIso3 and qIso4, located on LG-A1 (Chr.5), LG-A2 (Chr.8), LG-C1 (Chr.4) and LG-D2 (Chr.17), respectively. The high-isoflavone alleles were derived from Peking at qIso1 and qIso4 and from Tamahomare at qIso2 and qIso3. Several other groups have already reported the former two QTLs, but qIso2 and qIso3 are new discoveries. Our results indicate that the large variation in TIC measurements observed in the RILs could have resulted from the combined effects of alleles at the four QTLs derived from distantly related varieties.

Identification and characterization of a major QTL underlying soybean isoflavone malonylglycitin content

“…We identified a QTL associated with the contents of Gly and M_Gly on chromosome Gm11. Other major QTLs at this locus explaining 40% to 50% of variance were also reported in crosses between 'Essex' and 'Forrest' (Kassem et al 2004, Meksem et al 2001 and between 'Peking' and 'Tamahomare' (Yoshikawa et al 2010). Genomewide asso ciation analysis detected significant association with gly of homologous genes (Mameda et al 2018).…”

“…Isoflavone contents in soybean seeds are also affected by environmental factors, such as tempera ture during seed maturation, soil, and cultivation conditions (Hoeck et al 2000, Rasolohery et al 2008, Tsukamoto et al 1995. Multiple environmental evaluations with the same population indicated that the heritability of each isoflavone component is 0.6 to >0.9 (Yoshikawa et al 2010). The com parison of F6H expression among several lines with high, low, and null glycitein contents revealed a putative associa tion with accumulation of glycitein (Artigot et al 2013).…”

“…Many studies have identified loci controlling the accu mulation of isoflavones through quantitative trait locus (QTL) analysis (Akond et al 2014, Cai et al 2018, Gutierrez-Gonzalez et al 2010, 2011, Kassem et al 2004, Li et al 2014, Meksem et al 2001, Pei et al 2018, Primomo et al 2005, Yoshikawa et al 2010, Zeng et al 2009; at least 293 QTLs related to isoflavones (61 for daidzein, 69 for genistein, 72 for glycitein, 91 for total isoflavone contents) are listed in SoyBase (April 2019). Isoflavone contents in soybean seeds are also affected by environmental factors, such as tempera ture during seed maturation, soil, and cultivation conditions (Hoeck et al 2000, Rasolohery et al 2008, Tsukamoto et al 1995.…”

QTLs underlying the genetic interrelationship between efficient compatibility of Bradyrhizobium strains with soybean and genistein secretion by soybean roots

“…The current QTLs are in accordance with the results of previous measurements of isoflavonoid contents of soybean seeds. qDZS1 on Chr.8, qGNS1 on Chr.6 and qGNS3 on Chr.18 have been reported by Yoshikawa and colleagues [ 29 ], while qDZS3 and qGNS2 have been reported by Wang and colleagues [ 30 ]. This indicates that the isoflavonoid contents in seeds and their secretions from roots of soybean are regulated by the same genetic factors.…”

“…This indicates that the isoflavonoid contents in seeds and their secretions from roots of soybean are regulated by the same genetic factors. Daidzein and genistein levels in seeds are not very different among Peking, Tamahomare and the RILs [ 29 ]. In the roots of RIL plants, however, we found that daidzein secretions were nearly 100 times greater than genistein secretions in the early stage of growth (seven days after sowing).…”