Volume 13, Issue 4 (3-2023)                   2023, 13(4): 23-40 | Back to browse issues page


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Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Abstract:   (633 Views)
Abstract
The ability of phenological adjustment and accelerate maturation is one of the most drought tolerance mechanisms in crops. Tall fescue is one of the valuable forage and turf grasses that is used to prevent soil erosion and produce forage in pastures and is compatible with most soils and climates. In this research, yield potential and genetic variation of three phenological groups including mid-flowering group (parental group), early and late flowering groups each containing 25 genotypes, selected from a poly cross community, were studied under non-stress and water deficit conditions in the research farm of Isfahan University of Technology for two years. Irrigation was applied when 90 and 50% of available soil water were depleted for stress and normal environments, respectively. The results showed that there was considerable variation in the studied germplasms in terms of all studied traits and responses to water deficit stress. The highest value of genetic variation belonged to forage yield. The results showed that dry forage yield in the first and second harvest stress decreased by 17% and 52% due to water deficit, respectively. The highest estimate of heritability was related to the trait of day to anthesis and the lowest was related to the percentage of dry matter and forage yield. The results showed that the highest dry forage yield under non-stress conditions belonged to the late flowering group. Means comparison of genotypes showed that the highest dry forage yield under normal and water stress belonged to genotypes 10 (from America with 209.50 g/plant) and 3 (from Yasouj with 142.25 g/plant), respectively, in the late flowering group, genotypes 25 (from Shahrood with 383 g/plant) and 22 (from Poland with 178.50 g/plant), respectively in early flowering group and genotypes 25 (from Shahrood) with 222.50 and 182.25 g/plant in the parental group, respectively. The results indicate that the studied genotypes may have incomplete summer dormancy that should be investigated in future studies. Considerable genetic diversity between and within phenological groups and their different responses to drought stress can be used to develop and produce suitable synthetic varieties for soils with limited water resources.

Background and Objective: Plant water deficits may occur as a consequence of a seasonal decline in soil water availability, developing in the long term, or may result from drought spells (1). Tall fescue (Festuca arundinacea Schreb), the most important forage and turf grass species, is a widely used grass species that can be found abundantly in cold and dry regions (3). Tall fescue has a deep root system compared to other cool-season grasses. It has become an important grass for turf and soil conservation. Tall fescue is well cultivated in acidic soils with a pH equal to 4.8 to alkaline soils with a pH of 9.5 (2). In this research, the yield potential and genetic diversity of three different phenological groups of tall fescue genotypes were studied under non-stress and water deficit conditions.

Methods: Three different tall fescue groups in terms of phenology, each contained 25 genotypes, mid-flowering group (parental group), early and late flowering groups, selected from a polycross nursery, were studied under non-stress and water deficit conditions in the research farm of Isfahan University of Technology for two years.  In non-stress and water deficit stress conditions, irrigation was applied when 50% and 90% of the total available water was depleted from the root zone, respectively.

Results: The results of the analysis of variance revealed highly significant (p < 0.01) difference among the cultivars for the studied traits. Also, the interaction between cultivar and environment was significant for all the studied traits. The highest value of genetic variation belonged to dry forage yield. Water deficit stress significantly reduced dry forage yield in the first and second harvest by 44.80 and 18.28%, respectively. The highest estimate of heritability was related to the days to anthesis, and the lowest one was related to the percentage of dry matter and forage yield. The results showed that the highest dry forage yield under non-stress conditions belonged to the late flowering group but in the case of water deficit stress there was no significant difference between the early and late flowering groups. Also, the parental group showed the lowest percentage of yield reduction under moisture-stress conditions. A comparison of means showed the highest dry forage yield mean in the early-flowering group was related to genotypes 10 (with 209.50 g/plant) and 3 (with 142.25 g/plant) under non-stress and water deficit stress conditions, respectively. In late-flowering group, genotypes 25 (with 383 g/plant) and 22 (178.50 g/plant) had the highest dry forage yield under non-stress and water deficit stress conditions, respectively. Also, in the parental group, genotypes 25 had the highest dry forage yield with 222.50 and 182.25 g/plant under non-stress and water deficit stress conditions, respectively.

Conclusions: High variation in the studied germplasm for response to water deficit stress can be used to develop suitable cultivars in soils with limited water resources. Water deficit stress significantly reduced forage yield and important traits of tall fescue. However, the reaction of different genotypes to water deficit stress is different so it is possible to find tolerant and high-yielding genotypes suitable for cultivation in different regions. Water deficit stress reduced forage plant weight by 27%, 35%, and 7% in late, early, and parental groups, respectively. Genotypes of the parental group with the lowest percentage of yield reduction under water stress conditions can be assessed to select tolerant cultivars to water stress in future studies. The results of this study indicate that the studied genotypes may have incomplete summer dormancy that should be investigated in future studies. Considerable genetic diversity between and within phenological groups and their different responses to drought stress can be used to develop and produce suitable synthetic varieties for soils with limited water resources.

References:
1. Chaves, M.M., Oliveira, M.M., 2004. Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture. Journal of Experimental Botany 55(47): 23652384.
2. Khashij, Sh., Karimi, B., Makhdoumi, P., 2018. Phytoremediation with Festuca arundinacea. International Journal of Health and Life Sciences 4(2): 17.
3. Nematollahia, F., Tehranifara, A., Nematia, S.H., Kazemia, F., Gazanchianb, Gh.A., 2018. Improving early growing stage of Festuca arundinacea Schreb. using media amendments under water stress conditions. Desert 23(2): 295306.



 
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Type of Study: Research | Subject: Plant growth under stressful conditions
Received: 2022/04/15 | Accepted: 2023/02/22 | Published: 2023/02/26

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