Vegetative and reproductive development in wheat as affected by photoperiod sensitivity genes (Ppd-1).

THOMAS PEREZ GIANMARCO; GONZÁLEZ FERNANDA G

Congreso; XXI Reunión de la Sociedad Española de Fisiología Vegetal y XIV Congreso Hispano-Luso de Fisiología Vegetal; 2015

In orderto raise wheat yield potential, it has been suggested to increase the length ofspike growth period, during which number of fertile florets is set (LRP: LateReproductive Phase) while thermal time to anthesis remains unchanged. Toachieve that, previous phases (VP: Vegetative Phase and ERP: Early ReproductivePhase) should be shortened in exchange. Relatively independent regulation ofphotoperiod sensitivity (by Ppdgenes) of each of the sub-phases would allow optimising the duration of eachphase. Therefore, in this study, we assessed the effect of Ppd-1 genes on: i) thermal time to anthesis and the length of thesub-phases, and ii) the number of structures generated during each sub-phase.For this purpose, near isogenic lines (NIL?s) with one dominant allele (Ppd-D1, Ppd-B1 or Ppd-A1) onParagon spring wheat cultivar (triple recessive) were sown during 2013-2014growing season at INTA (National Institute of Agricultural Technology)Pergamino Experimental Site, Argentina. Time to anthesis varied amongst NIL?s(p<0.0001) mainly due to differences in LRP length (p=0.0001), but also inprevious sub-phases? length (VP+ERP, p=0.0001). Final leaf number differedamongst NIL?s (p<0.0001), while Paragon tended to have more spikelets perspike (p=0.0614). Number of fertile florets per plant ranged from 68 to 122,Paragon showing the highest value (p=0.0024). A second year of experiment isneeded, in order to explore shorter photoperiod.