遗传、气象和栽培因素对烤烟茎叶夹角的影响

【目的】为明确不同因素对烤烟茎叶夹角的影响。【方法】2019—2021年，在不同烟区设置不同试验，研究不同品种、气象、密度、施氮量等因素变化对烤烟茎叶夹角的影响，并分析不同因素的影响程度。【结果】（1）不同烤烟品种茎叶夹角差异显著，根据聚类分析将其分为茎叶夹角小、中、大三种类型，夹角小代表品种为红花大金元，夹角中代表品种包括中烟100、K326、云烟87等，夹角大代表品种为CB-1;(2)随移栽期推迟，茎叶夹角表现出减小的趋势，气温升高及累积光照辐射减少是影响夹角变化的主要气象因素，降水对夹角的影响不显著；（3）随株距增大、密度减小，茎叶夹角呈现出增大的趋势；部分试验随施氮量增加，茎叶夹角呈现增大趋势；（4）不同因素处理条件下茎叶夹角与农艺性状相关性不一致，品种因素下茎叶夹角与茎围正相关性较高，密度因素下茎叶夹角与叶片干重存在显著正相关性，而移栽期、施氮量条件下茎叶夹角与农艺性状无明显相关性；（5）不同因素对茎叶夹角的影响程度顺序为品种>密度>移栽期>施氮量。【结论】烤烟茎叶夹角受品种自身遗传因素的影响最大，其后依次为种植密度、气象条件，施氮量影响最小。

Effects of genetic,meteorological and cultivation factors on angle between stem and leaf of flue-cured tobacco

  Objective  This study aims to clarify the effects of different factors on stem-to-leaf angle of flue-cured tobacco.  Methods  From 2019 to 2021, different experiments were set up in different regions to study the effects of varieties, meteorology, density, nitrogen application rate on stem-to-leaf angle of flue-cured tobacco, and analyze the impact degree of each factor.  Results  (1) There were significant differences in stem-to-leaf angle among different flue-cured tobacco varieties. According to cluster analysis, they were divided into three types: small, medium and large stem-to-leaf angle. The representative variety with small stem-to-leaf angle was Honghua Dajinyuan, the representative varieties with medium stem-to-leaf angle included Zhongyan100, K326 and Yunyan 87, and the representative variety with large stem-to-leaf angle was CB-1. (2) With the delay of transplanting period, the stem-to-leaf angle showed a decreasing trend. The increase of temperature and the decrease of cumulative photo radiation were the main meteorological factors affecting the stem-to-leaf angle, and the influence of precipitation on stem-to-leaf angle was not significant. (3) The stem-to-leaf angle increased with the increase of plant spacing and the decrease of plant density. The stem-to-leaf angle increased with the increase of nitrogen application rate in some experiments. (4) The correlation between in partial experiments and agronomic characters was inconsistent under different factors. The positive correlation between stem-to-leaf angle and stem circumference was higher under variety as a factor, and there was a significant positive correlation between stem-to-leaf angle and leaf dry weight under density as a factor, but there was no significant correlation between stem-to-leaf angle and agronomic characters under transplanting period and nitrogen application rate. (5) The impact degree of different factors on stem-to-leaf angle was in the order of variety > density > transplanting period > nitrogen application rate.  Conclusion  The stem-to-leaf angle of flue-cured tobacco is largely affected by the genetic factors, followed by planting density and meteorological conditions, while the effect of nitrogen application rate is the least.