Abstract: Zoysia japonica is a warm-season grass species with various excellent characteristics. It is resistant to low mowing and has strong adaptability. However, its poor green retention seriously affects its wide application in North China. The ZjSGR gene has been shown to accelerate the degradation of chlorophyll in plants. Therefore, Zjsgr mutant plants may have better stay green trait. However, it is not clear whether the stress resistance will be decreased or not. In order to verify the stay green trait of Zjsgr mutant plants and further investigate their cold tolerance in Beijing, physiological indexes of Zjsgr mutant plants and control plants were measured and compared in Beijing in the early autumn, such as turf quality, chlorophyll content, relative water content, cell membrane permeability, MDA content and antioxidant enzyme activities. The results showed that turf quality, the chlorophyll content and peroxidase activity of the mutant plants were significantly higher than that of the control plants, and the membrane stability of the mutant plants was better （low EL）, which preliminarily indicated that the mutant plants had better cold resistance, and provided a theoretical basis for their subsequent popularization and application in northern China. It also laid a foundation for cultivating excellent zoysia grass lines with improved green period and stress resistance.

Key words: Cold tolerance, Zoysia japonica, Chlorophyll content, Membrane permeability, Antioxidant enzymes

摘要： 日本结缕草（Zoysia japonica）耐低修剪,适应性强,是一种具备多种优良特性的暖季型草种,但持绿性较差的缺点严重影响其在北方的广泛应用。日本结缕草滞绿（Zoysia japonica Stay Green,ZjSGR）基因已被证明可加速植物叶绿素的降解,因此Zjsgr突变植株可能具有良好的滞绿潜能,但其滞绿性获得提升的同时,抗逆性是否下降并不清楚。本研究为验证Zjsgr突变植株的滞绿性,并进一步探讨其在北京地区的耐寒性,检测对比了突变株系与同克隆来源对照植株在北京秋季降温后的生理指标,如草坪坪观质量、叶绿素含量、相对含水量、细胞膜透性、丙二醛含量及抗氧化酶活性。结果说明,突变植株的草坪质量、叶绿素含量、过氧化物酶活性显著高于对照植株,且突变植株在降温过程中细胞膜稳定性更好,即电解质渗透率低,初步说明突变植株具有更好的耐寒性,这为其未来在北方地区的推广运用提供了理论依据,并为培育持绿性和抗逆性多性状改良的优良结缕草株系奠定基础。

关键词: 耐寒性, 日本结缕草, 叶绿素含量, 细胞膜透性, 抗氧化酶