Poster: Reproductive Development

Abs # 457: Effects of transient shade stress on maize seed yield and ear phenotype

Presenter:	Moriarty, Timothy M, tim.moriarty@pioneer.com
Authors	Moriarty, Timothy M (A)   Mullen, Jeff  (A)
Affiliations:	(A): Pioneer Hi-Bred International, Inc.

Abiotic stress is a key factor impacting yield and performance of many crops, including maize. To further our understanding of environmental stress mechanisms and impacts on maize yield, we examined the effects of shade stress on yield and yield components such as kernel number and size as well as overall ear phenotype. Shade stress – an easily manipulated and controllable counterpart to abiotic stresses typically encountered under field conditions – was imposed at different stages of ear/kernel development and for different durations of stress. Treatments were devised to investigate: 1) the ability of stress-impacted kernels to recover from increased duration of shade applied at the beginning of development, and 2) the effect of transient stress applied at different times across the developmental period. Results indicated that short transient periods of shade stress impacted tip kernels such that they were unable to resume normal grain fill. Most periods of ear/kernel development between 0 and 16 days after pollination (DAP) were susceptible and resulted in a similar yield loss.