美国红枫幼树在沈阳地区的抗寒性比较

摘要

We chose one-year dormant shoots of different ages Acer rubrum (three and four years old) and Acer×freemanii‘Au-tumn Blaze’ (one year old) of excellent ornamental trees as research subjects, and selected one-year shoots of local native tree species Acer elegantulum (three years old) as control.We investigated the semi-lethal temperature (LT50) of relative electric conductivity and relative leakage of K+by different temperature (-10℃,-15℃,-20℃,-25℃,-30℃,-35℃and -40℃) with Logistic equation.Growth recovery experiments were conducted at 25℃ by water planting freezed shoots.The relative electric conductivity and the relative leakage of K+of Acer rubrum ( four years old), Acer rubrum (three years old), Acer×freemanii ‘Autumn Blaze’ and Acer elegantulum are rised with decreasing temperature.Accord-ing to the Logistic equation, the semi-lethal temperature of the relative electric conductivity are -30.1℃, -24.1℃, -35.4℃, -38.7℃, and the semi-lethal temperature of the relative leakage of K+are-29.6℃,-24.7℃,-33.7℃,-37.5℃.Among four species, the cold resistance of Acer elegantulum stick is the strongest, followed by Acer×freemanii‘Autumn Blaze’ , Acer rubrum ( four years old) and Acer rubrum ( three years old) .Combined with natural overwintering seedlings frost damage, Acer rubrum seedling above four years old as introduction material cultivated in Shenyang has better adaptability and higher overwintering ability.%以优良的观赏树种美国红枫为研究对象，选取3、4年生美国红枫和1年生改良美国红枫休眠枝条进行试验，并以当地乡土树种五角枫3年生苗的1年生休眠枝条作为对照，研究不同冷冻处理条件下（-10、-15、-20、-25、-30、-35、-40℃）枝条的相对电导率和钾离子（ K）＋相对渗出率，利用Logistic方程计算各树种的低温半致死温度（ LT50），并通过苗木生长恢复试验进行了验证。结果表明：美国红枫3年生和4年生苗、改良美国红枫、五角枫的相对电导率和K＋相对渗出率随温度的降低不断升高，通过相对电导率和K＋相对渗出率求得的美国红枫3年生和4年生苗、改良美国红枫、王角枫枝条LT50分别为-30．1、-24．1、-35．4、-38．7℃和-29．6、-24．7、-33．7、-37．5℃。由低温半致死温度和恢复生长试验综合分析得出，树木抗寒性由强到弱依次为：五角枫＞改良美国红枫＞美国红枫4年生苗＞美国红枫3年生苗。结合自然越冬后苗木冻害调查结果，认为选用4年生以上苗龄的美国红枫作为引种材料在沈阳地区栽培，其适应性好，能安全越冬。