Genetic variation for the duration of pre-anthesis development in durum wheat and its interaction with vernalization treatment and photoperiod

A recombinant inbred durum wheat population was grown under three contrasting regimes: long days following
vernalization (LDV), long days without vernalization (LD), and short days following vernalization (SDV). The length of
several pre-anthesis stages and the number of leaves and the phyllochron were measured. Different groups of genes
were involved in determining the phenology in the three treatments, as demonstrated by a quantitative trait locus
(QTL) analysis. The length of the period required to reach the terminal spikelet stage was correlated with the time to
anthesis only in the case of LDV- and LD-grown plants where the timing of anthesis depended on the final leaf number.
However, for SDV-grown plants, anthesis date was more dependent on the length of the period between the terminal
spikelet stage and anthesis and was independent of leaf number. The involvement of the phyllochron in determining
the duration of pre-anthesis development was also treatment-dependent. QTL mapping of the various flowering time
associated traits uncovered some novel loci (such as those associated with the phyllochron), in addition to confirming
the presence of several well-established loci.