Abstract
ABSTRACT The aim of this study was to evaluate the changes in osmoregulatory metabolism of cotton genotypes subjected to water deficit and recovery period. In a greenhouse, six cotton genotypes and two water managements were combined in a 6 x 2 factorial scheme, in a completely randomized design, evaluated after 14 and 22 days under water stress and recovery conditions, respectively. The water status, growth indicators and compatible solutes in the leaves were evaluated. The genotypes BRS Seridó, BRS Aroeira and BRS 7MH withstand better the stress condition because they had lower variations in their water potentials due to the osmotic adjustment and maintained their growth under water deficit conditions. The BRS 286 is the most sensitive genotype to the water deficit condition, since it showed greater variations in its water potential, which ultimately stopped its growth. Water replacement during the recovery period allowed growth resumption in most of the genotypes, mainly CNPA 5M and BRS 286. After the recovery period, variations in the concentrations of osmoregulators indicate the plasticity of cotton in regulating the concentrations of osmoregulators under favorable and unfavorable water conditions.
Highlights
Cotton (Gossypium hirsutum L.) cultivation encompasses an area of 956.7 thousand hectares
It was observed that the genotypes BRS 368 RF, BRS 286 and BRS 7MH, from the treatment with water deficit, had relative water content (RWC) percentages similar to those found in their respective controls, suggesting a recovery in cell water status (Figure 1B)
During the recovery period, it was observed that the genotypes BRS 368 RF, BRS Seridó and BRS Aroeira, from the treatment with water deficit, reduced their shoot dry matter production (28, 19 and 68%, respectively), compared to the respective control groups (Figure 2F)
Summary
Cotton (Gossypium hirsutum L.) cultivation encompasses an area of 956.7 thousand hectares. In the Northeast region there was a 13% reduction in its planted area in 2016 (CONAB, 2017), associated with the scarcity of water and irregular rainfalls This scenario causes water deficit in plants because it contributes to the loss of cell homeostasis and affects the processes of water absorption and accumulation in their tissues, with clear effects on growth and yield. To stimulate defense mechanisms against drought, the use of a water deficit period followed by a subsequent water replacement constitutes a recovery period. In this case, morphophysiological losses can be minimized by the osmotic adjustment, through the accumulation of solutes in the cells (Snowden et al, 2013). The synthesis and accumulation of soluble sugars and amino acids (proline) in the cytosol reduce the osmotic potential and increase cell turgor potential, contributing to the osmotic adjustment under water deficit conditions, as reported for cotton plants (Parida et al, 2007; Joseph et al, 2015)
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
