Abstract
Identification of traits strongly associated with high yield can help future gene engineering towards improvements of productivity. Here we systematically determine the major architectural and physiological features associated with high yield in two elite historical hybrid rice cultivars, i.e., YLY1 and LYP9. Data from a six-year experiment show that high yield of YLY1 are related to a number of architectural and physiological parameters. Compared to LYP9, YLY1 had 5.5% and 47.3% higher canopy photosynthesis under high and low photosynthetic photon flux densities, respectively, during the grain filling stage, an average 1.5% higher proportion of biomass allocation to above-ground tissues, a 4.5%–10.5% higher photosynthate reserve in leaf sheath before grain filling, and a more efficient photosynthate translocation during grain filling and finally an average 25.2% higher number of productive tillers. These features differ dramatically from features associated with high yield in YLY900 and Yongyou12#, two other high-yielding rice cultivars in China. These identified features and their combinations can support designing new strategies in the future high-yield rice breeding.
Highlights
Identification of architectural and physiological parameters associated with “ideotype”, defined as ideal canopy structure, plays a crucial role in guiding high-yield breeding programs (Donald 1968; Yuan et al 1994)
We systematically evaluated the photosynthetic properties at leaf and canopy levels together with the characteristics at source, sink and flow organs in YLY1 and compared them to those of LYP9, with a goal of identifying traits that contributed to high yield in YLY1
Chlorophyll Content of Leaves of Various Positions at Different Developmental Stages Comparison with LYP9, chlorophyll contents of the 1st leaf and 3rd leaf in YLY1 were higher at tillering stage (TS), panicle differentiation stage (PDS), milk stage (MS), and yellow ripe stage (YRS) (Table 1), and less difference of leaf chlorophyll contents for two cultivars was shown at MS
Summary
Identification of architectural and physiological parameters associated with “ideotype”, defined as ideal canopy structure, plays a crucial role in guiding high-yield breeding programs (Donald 1968; Yuan et al 1994). It was reported that a national project was initiated to develop ‘super’ rice in 1996 in China, taking account of both improved yield and desirable adaptation to certain planting areas (Cheng et al 1998; Cheng et al 2007). One major goal of the ‘super’ rice project is to develop varieties capable of producing 100 kg grain day− 1 ha− 1(Yuan 2000). The ‘super’ hybrid rice breeding program was initiated in 1998 which combines the “ideotype” approach with intersubspecific heterosis (Yuan 2000). Major progress on “ideotype” definition has been made through the ‘super’ hybrid rice breeding program. Liang-youpei-jiu (LYP9), an elite rice cultivar, was released as the phase I super hybrid rice cultivar which has a yield potential of 10.5 grain/ha. After LYP9, several elite rice hybrid cultivars have been released for commercial production
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
