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Acta Prataculturae Sinica ›› 2025, Vol. 34 ›› Issue (11): 184-194.DOI: 10.11686/cyxb2024501

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Evaluation of heat tolerance and post-heat recovery capacity of new varieties of tall fescue

Shi-xuan SUN1(), Qun-sen WANG1, Zhi-min YANG1, Ning-li FAN1, Tian HAO1, Nan-qing LIU2, Jing-jin YU1()   

  1. 1.College of Agro-grassland Science,Nanjing Agricultural University,Nanjing 210014,China
    2.Department of Landscape Architecture,Jiangsu Vocational College of Agriculture and Forestry,Jurong 212400,China
  • Received:2024-12-23 Revised:2025-03-10 Online:2025-11-20 Published:2025-10-09
  • Contact: Jing-jin YU

Abstract:

Breeding tall fescue (Festuca arundinacea) with summer high temperature- and humidity-tolerance is one of the available strategies for extending the growing season of forage grasses and meeting requirements for the sustainable development of grassland-based animal husbandry in climate transition zones of China. In this study, three new strongly-tillering forage-type tall fescue varieties, Nanmu NO.1, Nanmu NO.2, and Nanmu NO.3 independently developed through cross-breeding, were evaluated, and compared with the widely used commercial variety, Fit, as the control. Experiments were conducted in an artificial climate chamber to simulate heat stress and investigate the changes in physiological, growth and nutritional traits of each variety under environmental heat stress (38 ℃/33 ℃, day/night) and post-heat recovery conditions. The results indicated that heat stress led to an increase in electrolyte leakage (EL) and a decrease in relative leaf water content (RWC), chlorophyll (Chl) content, and net photosynthetic rate (Pn) for all varieties. However, compared with Fit, the three new varieties displayed significantly reduced EL and a smaller decrease in RWC, Chl, and Pn, indicating that the new varieties had superior heat tolerance and post-heat recovery ability than Fit. The three new varieties were characterized by high tiller and leaf numbers, low stem∶leaf ratio, good palatability, high crude protein content, and excellent quality. Among the tested varieties, Nanmu NO. 2 was the best. In conclusion, the three new varieties evaluated were all found to be heat-tolerant, high-yielding, high-quality forage grasses characterized by a strong tillering capacity and leaf production. They are suitable for sowing in climatic transition zones such as Jiangsu and other similar regions.

Key words: tall fescue, heat stress, physiological indicators, nutrient composition, growth trait