Inheritance and QTL analysis of chilling and heat requirements for flowering in an interspecific almond x peach (Texas x Earlygold) F2 population
Celia M. Cantin , Xin-Wei Wang, María Almira, Pere Arús, Iban Eduardo. Euphytica (2020) 216:51.
Blooming in temperate fruit species is
triggered by chilling and heat requirements (CR and
HR), with a wide range of requirements within the
same species. CR for flower bud dormancy release has
become a limiting factor for geographical adaptation
of fruit trees in warmer regions. The present study
investigated the genetic basis of CR and HR to break
dormancy and flowering time (FT) in an almond x
peach F2 progeny. FT, HR and CR were evaluated
over two consecutive years (2015/2016 and
2016/2017). Seven out of the eight identified quantitative
trait loci (QTLs) were found in both periods of
analysis. They affected eight traits, and included a
consistent QTL for breaking dormancy, CR and HR.
Two of them, affecting FT and HR for FT (GDHF),
colocalized in G1, and the remaining QTLs, affecting
chilling and heat requirements, both influenced by
dormancy breaking (DB), were located in G6. These
results indicate that factors not related to DB affect
flowering time in this population. Implications of the
results in peach breeding are discussed.
Blooming in temperate fruit species is
triggered by chilling and heat requirements (CR and
HR), with a wide range of requirements within the
same species. CR for flower bud dormancy release has
become a limiting factor for geographical adaptation
of fruit trees in warmer regions. The present study
investigated the genetic basis of CR and HR to break
dormancy and flowering time (FT) in an almond x
peach F2 progeny. FT, HR and CR were evaluated
over two consecutive years (2015/2016 and
2016/2017). Seven out of the eight identified quantitative
trait loci (QTLs) were found in both periods of
analysis. They affected eight traits, and included a
consistent QTL for breaking dormancy, CR and HR.
Two of them, affecting FT and HR for FT (GDHF),
colocalized in G1, and the remaining QTLs, affecting
chilling and heat requirements, both influenced by
dormancy breaking (DB), were located in G6. These
results indicate that factors not related to DB affect
flowering time in this population. Implications of the
results in peach breeding are discussed.