4.3 The implication for maize breeding
In this study, we found the subsequent impacts on grain filling of
stresses episodes around flowering mainly resulted from the disturbing
starch synthesis. Therefore, maize hybrids that have a high ability for
starch synthesis in kernel are likely more tolerant to DS, HS and DHS.
This should be received more attention in future breeding program. For
example, the droughtâtolerant lentil showed stronger ability of starch
synthesis in seeds (Sehgal et al., 2018). Meanwhile, we found the grain
weight was also reduced by shortened grain filling duration, accelerated
leaf senescence, and decreased photosynthesis in field. This also
implicated the importance of delaying senescence and improving
photosynthetic capacity for maize breeding. For example, the
drought-tolerant hybrid maintained
greater photosynthetic rates (+8-10%) compared with the conventional
hybrid (Lindsey, Barker, Metzger, Mullen, & Thomison, 2018). Meanwhile,
the heat-tolerant germplasm emphasized the importance of sufficient
CO2 exchange rate (Neiff, Trachsel, Valentinuz, Balbi,
& Andrade, 2016).