Weibull distribution and dynamics of germination of Rangpur lime seeds at different temperatures

Abstract: Rangpur lime is the most commonly used rootstock in Brazil, and its propagation occurs through seeds. Currently, no methodology is described in the prescriptions of the Rules for Seed Testing to perform the germination test of Rangpur lime. Thus, this research aimed to study the dynamics of germination in Rangpur lime seeds according to the Weibull distribution under the effect of different temperatures and lots. The experiment was conducted in a completely randomized design, with treatments arranged in a 3 × 5 factorial scheme (temperatures of 25, 30 and 35 °C for the germination test and five seed lots, respectively) and four replications. The percentage of germination, the number of days required obtaining 50% of germination, and the parameters of the Weibull equation were determined. The optimum temperature for germination of Rangpur lime seeds was 30 °C, with the first and last counts at 21 and 30 days after test installation, respectively. The germination process can be described by the three-parameter Weibull cumulative distribution function.

摘要：朗普尔柠檬（Rangpur lime）是巴西最常用的柑橘砧木，其繁殖方式为种子繁殖。目前，《种子检验规程》（Rules for Seed Testing）的相关条款中尚未规定适用于朗普尔柠檬种子发芽试验的检测方法。因此，本研究旨在探究不同温度与种子批条件下，朗普尔柠檬种子的发芽动态，并基于威布尔分布（Weibull distribution）开展相关分析。本试验采用完全随机设计（completely randomized design），处理设置为3×5因子设计：发芽试验温度分别为25、30、35℃，以及5个种子批，共设置4次重复。本研究测定了种子发芽率、达到50%发芽率所需的天数，以及威布尔方程的各项参数。试验结果显示，朗普尔柠檬种子发芽的最适温度为30℃，发芽试验的首次计数与末次计数分别为试验启动后的第21天和第30天。朗普尔柠檬的发芽过程可通过三参数威布尔累积分布函数进行拟合描述。