Document Type : Original Article
Authors
1
PhD Student, Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
2
Professor, Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
3
Former PhD Student, Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
Abstract
Objective
Recurrent droughts and limited water resources pose a serious threat to forage production and turf quality in arid and semi-arid regions. Identifying genotypes with high post-drought recovery potential can serve as a key strategy for enhancing resilience and sustainability in breeding programs. This study aimed to evaluate genetic diversity and identify superior tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) genotypes based on their recovery following drought stress.
Materials and Methods
A total of 108 tall fescue genotypes were evaluated under field conditions from 2018 to 2022 under two irrigation regimes (normal and severe drought stress). In the fourth year, irrigation was withheld for 60 days during the summer and subsequently resumed. The assessed traits included green and dry forage recovery, leaf height recovery, crown diameter recovery, and an overall recovery score. Data were analyzed using analysis of variance (ANOVA), correlation, and principal component analysis (PCA).
Results
The results of ANOVA revealed that irrigation regime, genotype, and their interaction significantly affected all measured traits (P < 0.01). Severe drought stress significantly reduced performance, with mean dry forage recovery under stress decreasing by approximately 24 percent compared to normal conditions. Nevertheless, substantial genetic variation was observed among genotypes. The average recovery score declined from 6.0 under regular irrigation to 4.4 under severe drought, indicating a significant impairment of recovery capacity. Strong positive correlations were observed between green forage recovery and other key traits: dry forage recovery (r = 0.96), leaf height recovery (r = 0.92), and crown diameter recovery (r = 0.81). PCA showed that the first two principal components collectively explained for 90 percent of the total variance. Based on this analysis, several genotypes exhibiting high recovery scores and adequate agronomic performance were identified as promising candidates for use as parents in breeding programs.
Conclusion
Post-drought recovery serves as a reliable and effective indicator for identifying drought-tolerant tall fescue genotypes. Genotypes exhibiting high recovery scores demonstrated not only enhanced restoration of performance following stress but also superior morphological characteristics. Therefore, incorporating post-drought recovery as a key screening criterion presents an effective strategy for improving turf quality and resilience under prolonged drought conditions.
Keywords
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