油茶含油率关键气候影响因子及模型分析

Analysis of key climate impact factors and model on oil content of Camellia

为找到影响主产区油茶含油率的关键物候期和关键气候因子,利用湖南省多地区2009-2017年共120项油茶样本鲜果含油率数据及临近的气象观测数据,采用相关分析和逐步回归方法,分析了油茶生长各阶段气候因子与鲜果含油率的关联性。结果表明:与鲜果含油率相关系数最高的气候因子分别为:全年的极端最高气温、果实膨大高峰期的日最高气温≥37℃天数、采后处理期的日降水量≥1mm天数、果实成熟期的最长连续无雨日数、油脂转化和积累高峰期的极端最高气温和果实第一次膨大期的平均最小相对湿度。基于420项气候因子构建的油茶鲜果含油率的模型精度最高。综合分析得出,油脂转化和积累高峰期是影响油茶鲜果含油率的关键物候期,极端最高气温、日平均气温≥20℃的积温和最长连续无日照天数是影响鲜果含油率的关键气候因子。其中鲜果含油率与极端最高气温呈显著负相关,而与日平均气温≥20℃的积温呈显著正相关,与最长连续无日照天数呈显著负相关,说明油脂转化需要适宜的温度和日照条件。

To better understand the climate impact on camellia (Camellia oleifera L.,oil-tea camellia) seed oil,data of 120 items on fresh fruit oil content of camellia and the adjacent meteorological observation data were collected and analyzed from 2009 to 2017 in Hunan Province.Correlation between climatic factors and fresh fruit oil content in each stage of camellia were obtained by correlation analysis and stepwise regression method.Results showed that the highest correlation coefficient between climatic factors with the oil-content rate at each stage included annual extreme maximum temperature,daily maximum temperature above 37°C in the peak period of fruit enlargement,days of daily precipitation above 1 mm in the post-harvest treatment period,the longest continuous no rain days at fruit ripening period,the extreme maximum temperature during the peak period of fat conversion and accumulation stage,and the average minimum relative humidity of the first expansion period of the fruit respectively.Based on 420 climatic factors,the model of camellia fruit oil content had high precision.According to comprehensive analysis,the most important phenological period affecting the fruit oil was the peak of oil conversion and accumulation.And the key climatic factors were extreme maximum temperature,accumulated temperature of daily average temperature ≥20℃,the longest continuous day without sunshine,and the longest continuous number of days without rain.