Phenology and Floret Development as Affected by the Interaction between <i>Eps-7D</i> and <i>Ppd-D1</i>

• Main Authors: Priyanka A. Basavaraddi, Roxana Savin, Stefano Bencivenga, Simon Griffiths, Gustavo A. Slafer
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Plants
• Subjects: spike fertility; leaf appearance; spikelet primordia; earliness per se; photoperiod
• Online Access: https://www.mdpi.com/2223-7747/10/3/533

Earliness per se (<i>Eps</i>) genes may play a critical role in further improving wheat adaptation and fine-tuning wheat development to cope with climate change. There are only few studies on the detailed effect of <i>Eps</i> on wheat development and fewer on the interaction of <i>Eps</i> with the environment and other genes determining time to anthesis. Furthermore, it seems relevant to study every newly discovered <i>Eps</i> gene and its probable interactions as the mechanisms and detailed effects of each <i>Eps</i> may be quite different. In the present study, we evaluated NILs differing in the recently identified <i>Eps-7D</i> as well as in <i>Ppd-D1</i> at three temperature regimes (9, 15 and 18 °C) under short day. The effect of <i>Eps-7D</i> on time to anthesis as well as on its component phases varied both qualitatively and quantitatively depending on the allelic status of <i>Ppd-D1</i> and temperature, being larger in a photoperiod-sensitive background. A more noticeable effect of <i>Eps-7D</i> (when combined with <i>Ppd-D1b</i>) was realised during the late reproductive phase. Consequently, the final leaf number was not clearly altered by <i>Eps-7D</i>, while floret development of the labile florets (florets 2 and 3 in this case, depending on the particular spikelet) was favoured by the action of the <i>Eps-7D-late</i> allele, increasing the likelihood of particular florets to become fertile, and consequently, improving spike fertility when combined with <i>Ppd-D1b</i>.