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Acta Prataculturae Sinica ›› 2024, Vol. 33 ›› Issue (2): 164-184.DOI: 10.11686/cyxb2023105

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Responses of different oat cultivars to low-nitrogen stress

Ying LUO(), Cong LI, Pei WANG, Li-hua TIAN, Hui WANG, Qing-ping ZHOU, Ying-xia LEI()   

  1. Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station,Southwest Minzu University,Chengdu 610041,China
  • Received:2023-04-04 Revised:2023-05-24 Online:2024-02-20 Published:2023-12-12
  • Contact: Ying-xia LEI

Abstract:

In this study, we aimed to investigate the morphological and physiological responses of oat (Avena sativa) to low-nitrogen stress, and to screen for A.sativa cultivars that are tolerant to low-nitrogen conditions. Eighteen A. sativa cultivars were grown using a hydroponic system with two different nitrogen concentrations: sufficient nitrogen (4 mmol·L-1, CK) and low nitrogen (0.4 mmol·L-1, LN). After 21 days of treatment, seven morphological indexes and 14 physiological indexes were measured and analyzed. The data were subjected to correlation analysis and principal component analysis, and a comprehensive evaluation was carried out by combining a cluster analysis and a membership function analysis. The results showed that: 1) Under low-nitrogen stress, the plant height, aboveground biomass, nitrate nitrogen content, nitrate reductase activity, glutamine synthase activity, glutamate dehydrogenase activity, soluble sugars content, and soluble protein content showed a decreasing trend; glutamate synthase activity, malondialdehyde content, and reactive oxygen species content showed an increasing trend; and the changes in root length, underground biomass, and root-shoot ratio varied. 2) Among the 21 physiological indicators, 12 pairs showed significant correlations. Among these 12, the root:shoot ratio and root dry weight were significantly positively correlated, and glutamine synthetase activity and soluble protein content were significantly negatively correlated. 3) Biomass, nitrogen metabolism factors, photosynthetic factors, antioxidant factors, and osmotic regulatory factors of A. sativa under low-nitrogen stress were identified as important indicators of tolerance to low-nitrogen conditions. 4) The 18 cultivars of A. sativa were divided into three categories: strongly tolerant, moderately tolerant, and sensitive. The strongly tolerant varieties included Qinghai sweet oat and Qinghai 444. The sensitive varieties included Haywire and Qingyan No. 2.

Key words: Avena sativa, low nitrogen tolerance, physiological response, comprehensive evaluation