Genomic regions controlling vernalization and photoperiod responses in oat

Abstract

Oat genotypes vary for photoperiod and vernalization responses. Vernalization often promotes earlier flowering in fall-sown but not spring-sown cultivars. Longer photoperiods also promote earlier flowering, and the response to longer photoperiods tends to be greater in cultivars from higher latitudes. To investigate the genetic basis of photoperiod and vernalization responses in oat, we mapped QTLs for flowering time under four combinations of photoperiod and vernalization treatments in the Ogle x TAM O-301 mapping population in growth chambers. We also mapped QTLs for flowering time in early spring and late-spring field plantings to determine the genetic basis of response to early spring planting in oat. Three major flowering-time QTLs (on linkage groups OT8, OT31 and OT32) were detected in most conditions. QTLs with smaller effects on flowering were less-consistently observed among treatments. Both vernalization-sensitive and insensitive QTLs were discovered. Longer photoperiod or vernalization alone tended to decrease the effects of flowering-time QTLs. Applied together, longer photoperiod and vernalization interacted synergistically, often on the same genomic regions. Earlier spring planting conferred an attenuated vernalization treatment on seeds. The major flowering-time QTLs mapped in this study matched those mapped previously in the Kanota x Ogle oat mapping population. Between these two studies, we found a concordance of flowering-time QTLs, segregation distortion, and complex genetic linkages. These effects may all be related to chromosomal rearrangements in hexaploid oat. Comparative mapping between oat and other grasses will facilitate molecular analysis of vernalization response in oat.

Mapping dynamic QTL for plant height in triticale

“…Following the approach suggested by Holland et al [37] the significance threshold was set at P  < 5.3e-5.…”

“…We used an α-level of 0.05 and followed the suggestion of Holland et al [37] dividing the α-level by the number of possible independent pairwise interactions between chromosome regions, assuming two separate regions per chromosome ( P  < 5.3e-5). The circular plots illustrating the epistatic interactions were created with Circos [38].…”

A molecular linkage map with associated QTLs from a hulless × covered spring oat population

“…Epistatic interactions between marker loci were also reported in the KO RI population (Holland et al 1997) and the OT RI population (Holland et al 2002).…”

“…QTLs affecting four agronomic and two kernel quality traits (Siripoonwiwat et al 1996) and vernalization response to heading date and plant height (Holland et al 1997) were detected in the 'Kanota' 'Ogle' (KO) population. Vernalization and photoperiod response QTLs were detected in the 'Ogle' 'TAM O-301' (OT) population (Holland et al 2002). QTLs affecting chemical composition and kernel characteristics were found in both the KO and 'Kanota' 'Marion' (KM) RI populations (Kianian et al 1999(Kianian et al , 2000Groh et al 2001).…”

Adult Plant Development in Triticale (× Triticosecale Wittmack) Is Controlled by Dynamic Genetic Patterns of Regulation

“…For the significance level for the epistatic QTL we used an α-level of 0.05 and followed the suggestion of Holland et al (2002) dividing the α-level by the number of possible independent pairwise interactions between chromosome regions, assuming two separate regions per chromosome ( P < 5.3e-5). The circular plots illustrating the epistatic interactions were created with Circos (Krzywinski et al 2009).…”