Mitigation of water limitation effects on flower traits, fruit development and yield of chili pepper (Capsicum annuum L.) by brassinosteroid mimic

Abstract

Importance of the work: 7,8-Dihydro-8α-20-hydroxyecdysone (DHECD) is
a brassinosteroid mimic, that could enhance the resilience and sustainability of
chili pepper cultivation, which frequently has water shortage problems, particularly
in Northeast Thailand.
Objectives: to investigate the impact of DHECD on chili pepper traits, flower anatomy,
fruit development and yield under well-irrigated and water-limited conditions.
Materials & Methods: Four treatments (well irrigated with and without DHECD
and water limitation with and without DHECD) were applied during the floral induction
stage of development. Under water-limited conditions (50% pot water capacity for
5 d), 0.1 μM DHECD was applied to plants aged 60 d during the floral induction stage
of reproductive development.
Results: DHECD enhanced floral length, influencing flower anatomy by promoting the
tissue layer that merged with the ovary wall to form the pericarp, as well as facilitating
tapetum layer formation under water-limited conditions. DHECD alleviated the delays in
flower, microspore and fruit development caused by the water limitation. Furthermore,
DHECD ensured regular fruit growth, thick pericarp layer development, increased pollen
germination, a high fruit set percentage and reduced fruit drop percentage.
Main finding: DHECD application during the floral induction stage strategically
enhanced chili pepper resilience to water limitation, presenting a valuable approach
for sustainable production in water-limited environments.