Genotypic‐specific responses caused by prolonged drought stress in smooth bromegrass (Bromus inermis): Interactions with mating systems

Abstract

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.

Genetic Parameters and Selection in Full-Sib Families of Tall Fescue Using Best Linear Unbiased Prediction (BLUP) Analysis of Animal Breeding and Genetic

“…A positive genetic correlation between dry forage yield (DFY) with plant height (PH), crown diameter (CD), number of stems per plant (NS), and owering time (FLO) indicates that selection based on higher PH, CD, NS, and FLO could lead to the selection of genotypes with better yield productivity. Similar to our ndings, several researchers have been reported positive association between forage yield with yield related traits (such as PH, CD, and NS) and owering date in some perennial grass species [11,14,15,18].…”

“…Therefore, knowledge on the genetic diversity, heritable variations, and genetic correlation among the selection characters is essential for selecting superior genotypes and improving the e ciency of breeding programs [11,12]. In grass species, most of the economical traits such as forage or biomass yield are genetically complex traits with quantitative inheritance and affected by the genotype and environment interaction [13,14]. The interaction of genetic by year can limit the yield stability and selection of superior genotypes, so assessment of genotypes in different years is one of the important parts of the breeding programs [13; 15].…”

Half‐sib mating for inheritance analysis of post‐drought recovery and productivity related traits in tall fescue

“…Saeidnia et al. (2019, 2020) also reported the relatively high values of heritability for yield components and recovery related traits in smooth bromegrass.…”

“…A moderate to high value of narrow sense heritability was reported for recovery yield (0.59) in orchardgrass and smooth bromegrass (0.69) (Pirnajmedin et al, 2018;Saeidnia et al, 2019). Saeidnia et al (2019Saeidnia et al ( , 2020 also reported the relatively high values of heritability for yield components and recovery related traits in smooth bromegrass.…”

Inheritance of Summer Dormancy, Persistence and Productivity Using Half-sib Matting in Tall Fescue 

“…It seems that higher persistence in half-sib families can be due to the heterosis expression (hybrid vigor) in polycross progenies which can open a new breeding opportunity. Saeidnia et al [30,31] documented that open pollination improved persistence in orchardgrass (Dactylis glomerata L.), while did not affect this trait in smooth bromegrass (Bromus inermis L.). One of the main objectives in the plant breeding programs is studying the inheritance of traits [32].…”