The consequences of recurrent drought events compared with a single drought, and drought's interaction with deliberate selfing compared with open‐pollination on postdrought recovery and persistence of smooth bromegrass, are not clear. This research was conducted to investigate the effects of recurrent drought stresses compared with a single drought on stress response, poststress recovery and persistence of full‐sib and half‐sib progenies of smooth bromegrass. During this study, 25 selfed (S1) and 25 open‐pollinated (OP) progenies of smooth bromegrass created in 2012 were evaluated in the field under normal and recurrent drought stress during 2013–2016. After the first harvest of above‐ground biomass in 2016, irrigation was withheld in both environments for 2 months; plants were subsequently re‐watered and evaluated. Recurrent drought stress changed the relationships between different traits. Moreover, prolonged drought stress resulted in increased plant productivity (recovery aerial biomass; RABI) of S1 and OP populations in recurrent drought stress compared with normal environment. Mandatory selfing increased persistence of smooth bromegrass genotypes but did not affect recovery after prolonged drought stress. Results revealed that, selecting among S1 families would be more effective than OP ones.
The effect of prolonged drought treatments on persistence, growth traits, drought survival and post-drought recovery was investigated in two sets of differently managed genotypes of cocksfoot (Dactylis glomerata L.). In total, 72 genotypes (two sets of 36 managed for seed and forage harvest, respectively) were evaluated for agro-morphological traits in the field during 2013–15 under normal and deficit irrigation regimes. In the fourth year (2016), irrigation was withheld in both irrigation treatments for 2 months and then plants were re-watered to investigate the effect of prolonged drought regimes on traits related to post-drought recovery. The deficit irrigation regime decreased persistence and recovery. These reductions were lower in the seed-management than the forage set, which indicates that delaying the first harvest of the seed-management treatment to maximise seed production led to lower impact of drought stress. The seed-management treatment also had lower persistence. The forage-management treatment had higher recovery under normal irrigation, whereas under deficit irrigation, the seed-management treatment had higher recovery. Association analysis showed the possibility of selecting genotypes having high values of persistence and drought tolerance. Results also showed a negative correlation between days to flowering and recovery after drought, indicating that selection for earliness may improve survivability and persistence of these plants. Superior genotypes with higher forage production and better recovery, persistence and drought tolerance may be recommended for development of synthetic cultivars.
In arid and semiarid regions, successful recovery from drought may be of more economic significance than plant productivity during a dry season. This research was conducted to investigate the effects of pre-drought irrigation and defoliation managements (seed and forage managements) on post-drought recovery of diverse smooth bromegrass (Bromus inermis Leyss.) genotypes, and to identify growth traits associated with persistence and recovery as indices for selecting superior genotypes. Thirty-six genotypes were field evaluated in two separate experiments of seed and forage managements during 2013-2015 under well-watered and deficit irrigation regimes. In the fourth year (2016), irrigation was withheld from both moisture regimes for two months (almost complete senescence) and then plants were re-watered to find the effect of prolonged drought stress on post-drought recovery. Pre-drought irrigation increased persistence of genotypes relative to the well-watered treatment in the seed management experiment. In the seed management trial, genotypes had greater recovery under deficit irrigation when compared to forage management counterpart. There was no significant difference between seed and forage management experiments under the well-watered regime in this respect. Positive correlations were observed between recovery after prolonged drought and total aerial biomass, persistence, and winter growth vigor under both irrigation regimes. Superior genotypes were identified as having more productivity, better recovery, higher persistence, and drought tolerance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.