朱砂梅花朝向变异影响传粉者访花行为和传粉效率

doi:10.17520/biods.2025221

摘要/Abstract

摘要： 植物的花朝向受生物和非生物因素影响, 反映了植物对环境的适应, 不同的花朝向可能影响植物花部性状及传粉者访花进而影响繁殖成功。然而, 木本植物个体内的花朝向变异对传粉者访花及传粉效率影响的研究尚少。朱砂梅(Prunus mume f. purpurea)是具重要观赏和经济价值的木本植物, 单株上存在3种朝向的花型(朝上型、水平型和朝下型), 是比较不同花朝向对传粉者访花行为和传粉效率影响的理想材料。本文调查了朱砂梅不同植株上花朝向的比例, 测定了花部性状、单花寿命、花粉活力和柱头可授性, 并研究了其传粉特性。结果表明: 朱砂梅植株中朝下型花的占比(53.2% ± 1.8%)极显著高于水平型花(29.7% ± 1.7%)和朝上型花(17.1% ± 1.3%) (P < 0.001)。不同朝向花的花部性状不同, 朝下型花的雄性资源投入(雄蕊长度、数量和花粉量)极显著高于水平型花和朝上型花(P < 0.001), 且单花期更长, 其柱头可授性和花粉活力更强。中华蜜蜂(Apis cerana)是朱砂梅的主要传粉者, 偏好访问朝下型花, 表现为朝下型花的访花频率更高、单花访问时间更长以及一次移出与落置的花粉量更多。综上, 朱砂梅不同朝向花的花部性状分化影响了传粉者访花, 朝下型花的高占比优势可能是朱砂梅提升繁殖成功率的一种适应性策略。

关键词: 花朝向, 朱砂梅, 花部性状, 传粉效率

Abstract

Aims: Flower orientation is shaped by both biotic and abiotic factors, reflecting their adaptation to the environment. Such variation may influence floral traits and pollinator visitation, ultimately affecting plant reproductive success. However, the effect of within-individual variation in flower orientation on pollinator visitation and pollination efficiency remains understudied in woody plants. Prunus mume f. purpurea is a woody species with important ornamental and economic value. It exhibits three different flower orientations (upward, horizontal, and downward) within a single plant. It is an ideal model for exploring the effects of flower orientation on pollinator visitation and pollination efficiency.

Methods: We investigated the proportion of flowers with different orientations and quantified the floral traits, floral longevity, pollen viability, stigma receptivity, and the pollination characteristics.

Results: Our results showed that proportion of downward flowers (53.2% ± 1.8%) was significantly higher than that of horizontal (29.7% ± 1.7%) and upward (17.1% ± 1.3%) flowers (P < 0.001). Differences in floral traits were observed among the three flower orientations. Specifically, downward flowers exhibited greater male reproductive resource investment than horizontal and upward flowers (P < 0.001), including longer stamens, a higher number of stamens, and greater pollen production. Downward flowers also exhibited significantly longer floral longevity, as well as higher stigma receptivity and pollen viability compared to horizontal and upward flowers. Apis cerana was identified as the primary pollinator of P. mume f. purpurea. Apis cerana visited downward flowers significantly more frequently, spent significantly more time per visit, and transferred significantly more pollen grains per visit than it did with upward flowers.

Conclusion: Our findings demonstrate that the differentiation in floral traits of different orientations in P. mume f. purpurea influences pollinator visitation behavior. Therefore, our study suggests that the proportion of downward flowers in P. mume f. purpurea may enhance reproductive success as an adaptive strategy.

Key words: flower orientation, Prunus mume f. purpurea, floral traits, pollination efficiency

葛湘湘, 徐玉洁, 汤菊 (2025) 朱砂梅花朝向变异影响传粉者访花行为和传粉效率. 生物多样性, 33, 25221. DOI: 10.17520/biods.2025221.

Xiangxiang Ge, Yujie Xu, Ju Tang (2025) Effect of flower orientation variation on pollinator foraging behavior and pollination efficiency in Prunus mume f. purpurea. Biodiversity Science, 33, 25221. DOI: 10.17520/biods.2025221.

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链接本文: https://www.biodiversity-science.net/CN/10.17520/biods.2025221

https://www.biodiversity-science.net/CN/Y2025/V33/I9/25221

图/表 5

图1 朱砂梅花部形态、传粉者访花、性状测量方法及开花进程。(A)植株枝条上自然生长的3种朝向的花(白色箭头示); (B-D)中华蜜蜂访问朝上型(B)、水平型(C)及朝下型(D)花朵; (E)花部性状测量参数: a. 花萼长; b. 花萼宽; c. 花冠直径; d. 花瓣长; e. 花瓣宽; f. 雄蕊长; g. 花药长; h. 雌蕊长。(F)不同开花时期的花形态变化: I. 花苞期; II. 始花期; III. 盛花期; IV. 末花期; V. 枯萎期。

Fig. 1 Floral morphology, pollinator visitation, measurement methodology and flowering process in Prunus mume f. purpurea. (A) Naturally growing flowers with three orientations (indicated by white arrows) on a branch. (B-D) Apis cerana visit upward (B), horizontal (C), and downward (D) flowers. (E) Measurements of floral traits: a. Calyx length; b. Calyx width; c. Corolla diameter; d. Petal length; e. Petal width; f. Stamen length; g. Anther length; h. Pistil length. (F) The flower morphology changes at different flowering dynamic periods: I. Bud stage; II. Earlier flowering stage; III. Blooming stage; IV. Late flowering stage; V. Withering stage.

表1 朱砂梅朝上型、水平型和朝下型花的花部性状比较(平均值 ± 标准误)。加粗表示朝下型花的性状显著大于朝上型花。花部特征样本量记为N, 不同小写字母表明不同性状有显著差异(P < 0.05)。

Table 1 Comparisons of floral traits among upward, horizontal, and downward flowers of Prunus mume f. purpurea (mean ± SE). Floral traits of downward flowers significantly larger than those of upward flowers are in bold. The sample size of floral characters is N. Different lowercase letters indicate significant differences in flower traits (P < 0.05).

花部性状 Floral traits	样本量 N	朝上型 Upward	水平型 Horizontal	朝下型 Downward	Wald χ²	df	P
花萼长 Calyx length (mm)	30	4.86 ± 0.09^a	4.49 ± 0.09^b	4.51 ± 0.09^b	10.069	2	0.007
花萼宽 Calyx width (mm)	30	3.91 ± 0.07^a	3.52 ± 0.06^b	3.42 ± 0.07^b	31.355	2	< 0.001
花冠直径 Corolla diameter (mm)	30	24.81 ± 0.30^a	24.12 ± 0.28^a	24.89 ± 0.30^a	4.131	2	0.127
花瓣长 Petal length (mm)	30	10.24 ± 0.09^a	9.91 ± 0.17^ab	9.64 ± 0.16^b	8.821	2	0.012
花瓣宽 Petal width (mm)	30	10.20 ± 0.09^a	9.54 ± 0.15^b	9.30 ± 0.17^b	21.932	2	< 0.001
雄蕊长 Stamen length (mm)	30	8.81 ± 0.10^b	8.82 ± 0.20^b	9.51 ± 0.14^a	13.576	2	0.001
花药长 Anther length (mm)	30	0.51 ± 0.10^a	0.50 ± 0.01^a	0.38 ± 0.03^b	36.420	2	< 0.001
雄蕊数目 Number of stamens	30	50.27 ± 0.44^b	47.47 ± 0.66^c	57.57 ± 0.57^a	166.383	2	< 0.001
雌蕊长 Pistil length (mm)	30	10.26 ± 0.19^a	9.79 ± 0.32^a	10.71 ± 0.21^a	5.745	2	0.057
花粉数 Number of pollen grains	25	26,216.0 ± 921.3^b	29,944.0 ± 872.7^a	32,080.0 ± 903.3^a	21.524	2	< 0.001
花粉体积 Pollen volume (μm³)	40	12,930.03 ± 355.76^a	13,166.58 ± 476.43^a	13,819.83 ± 388.69^a	2.525	2	0.283
胚珠数 Number of ovules	20	2.1 ± 0.1^a	2.0 ± 0.1^a	2.0 ± 0.1^a	1.307	2	0.520
单花寿命 Flower longevity (d)	17	5.47 ± 0.40^c	6.76 ± 0.49^b	8.41 ± 0.48^a	20.689	2	< 0.001

花部性状 Floral traits	样本量 N	朝上型 Upward	水平型 Horizontal	朝下型 Downward	Wald χ²	df	P
花萼长 Calyx length (mm)	30	4.86 ± 0.09^a	4.49 ± 0.09^b	4.51 ± 0.09^b	10.069	2	0.007
花萼宽 Calyx width (mm)	30	3.91 ± 0.07^a	3.52 ± 0.06^b	3.42 ± 0.07^b	31.355	2	< 0.001
花冠直径 Corolla diameter (mm)	30	24.81 ± 0.30^a	24.12 ± 0.28^a	24.89 ± 0.30^a	4.131	2	0.127
花瓣长 Petal length (mm)	30	10.24 ± 0.09^a	9.91 ± 0.17^ab	9.64 ± 0.16^b	8.821	2	0.012
花瓣宽 Petal width (mm)	30	10.20 ± 0.09^a	9.54 ± 0.15^b	9.30 ± 0.17^b	21.932	2	< 0.001
雄蕊长 Stamen length (mm)	30	8.81 ± 0.10^b	8.82 ± 0.20^b	9.51 ± 0.14^a	13.576	2	0.001
花药长 Anther length (mm)	30	0.51 ± 0.10^a	0.50 ± 0.01^a	0.38 ± 0.03^b	36.420	2	< 0.001
雄蕊数目 Number of stamens	30	50.27 ± 0.44^b	47.47 ± 0.66^c	57.57 ± 0.57^a	166.383	2	< 0.001
雌蕊长 Pistil length (mm)	30	10.26 ± 0.19^a	9.79 ± 0.32^a	10.71 ± 0.21^a	5.745	2	0.057
花粉数 Number of pollen grains	25	26,216.0 ± 921.3^b	29,944.0 ± 872.7^a	32,080.0 ± 903.3^a	21.524	2	< 0.001
花粉体积 Pollen volume (μm³)	40	12,930.03 ± 355.76^a	13,166.58 ± 476.43^a	13,819.83 ± 388.69^a	2.525	2	0.283
胚珠数 Number of ovules	20	2.1 ± 0.1^a	2.0 ± 0.1^a	2.0 ± 0.1^a	1.307	2	0.520
单花寿命 Flower longevity (d)	17	5.47 ± 0.40^c	6.76 ± 0.49^b	8.41 ± 0.48^a	20.689	2	< 0.001

表2 朱砂梅朝上型、水平型和朝下型花的开花动态、形态变异及持续时间

Table 2 Morphological variation and timing of flowering dynamic stages in upward, horizontal, and downward flowers of Prunus mume f. purpurea

时期 Flowering stages	花形态变化 Changes in flower morphology	开花动态(开放的天数) (d) Flowering dynamics (number of days) (d)
时期 Flowering stages	花形态变化 Changes in flower morphology	朝上型 Upward	水平型 Horizontal	朝下型 Downward
花苞期 Bud stage (I)	花被片紧包, 柱头伸出不明显, 花药呈黄色。 The perianth segments are tightly wrapped, the stigma does not protrude prominently, and the anthers are yellow.	0	0	0
始花期 Earlier flowering stage (II)	花被片包裹, 花冠口微微张开, 花柱逐渐伸长且已明显可见, 雄蕊开始平展。 The perianth segments are wrapped, the corolla is slightly open, the style gradually elongates so that it is clearly visible, and the stamens begin to stretch flat.	2-3	2-3	2-4
盛花期 Blooming stage (III)	花被片松动展开, 花柱伸长至最长, 柱头具有黏性; 雄蕊逐渐平展, 花药开裂并外张, 散粉后逐渐内收。 The perianth segments loosen and unfold, the style elongates to its maximum length, and the stigma becomes sticky. The stamens gradually stretch flat, the anthers crack open outward, and they gradually adduct after pollen dispersal.	3-4	3-5	4-6
末花期 Late flowering stage (IV)	花瓣部分掉落, 花色变浅, 雄蕊开裂散粉后卷曲并包围花柱, 柱头开始褐化。 Part of the petals fall off, and the flower color becomes lighter. Following cracking and pollen dispersal, the stamens curl up and surround the style, and the stigma begins to brown.	4-5	5-6	7-8
枯萎期 Withering stage (V)	花瓣呈褐色枯萎, 雌蕊直立外伸, 柱头褐变。 The petals turn brown and wither. The pistil remains erect and elongates, while the stigma undergoes browning.	5-6	6-7	8-9

表2 朱砂梅朝上型、水平型和朝下型花的开花动态、形态变异及持续时间

Table 2 Morphological variation and timing of flowering dynamic stages in upward, horizontal, and downward flowers of Prunus mume f. purpurea

时期 Flowering stages	花形态变化 Changes in flower morphology	开花动态(开放的天数) (d) Flowering dynamics (number of days) (d)
时期 Flowering stages	花形态变化 Changes in flower morphology	朝上型 Upward	水平型 Horizontal	朝下型 Downward
花苞期 Bud stage (I)	花被片紧包, 柱头伸出不明显, 花药呈黄色。 The perianth segments are tightly wrapped, the stigma does not protrude prominently, and the anthers are yellow.	0	0	0
始花期 Earlier flowering stage (II)	花被片包裹, 花冠口微微张开, 花柱逐渐伸长且已明显可见, 雄蕊开始平展。 The perianth segments are wrapped, the corolla is slightly open, the style gradually elongates so that it is clearly visible, and the stamens begin to stretch flat.	2-3	2-3	2-4
盛花期 Blooming stage (III)	花被片松动展开, 花柱伸长至最长, 柱头具有黏性; 雄蕊逐渐平展, 花药开裂并外张, 散粉后逐渐内收。 The perianth segments loosen and unfold, the style elongates to its maximum length, and the stigma becomes sticky. The stamens gradually stretch flat, the anthers crack open outward, and they gradually adduct after pollen dispersal.	3-4	3-5	4-6
末花期 Late flowering stage (IV)	花瓣部分掉落, 花色变浅, 雄蕊开裂散粉后卷曲并包围花柱, 柱头开始褐化。 Part of the petals fall off, and the flower color becomes lighter. Following cracking and pollen dispersal, the stamens curl up and surround the style, and the stigma begins to brown.	4-5	5-6	7-8
枯萎期 Withering stage (V)	花瓣呈褐色枯萎, 雌蕊直立外伸, 柱头褐变。 The petals turn brown and wither. The pistil remains erect and elongates, while the stigma undergoes browning.	5-6	6-7	8-9

图2 中华蜜蜂访问朱砂梅3种朝向花的单花访问时间(A)和访花频率(B)比较(平均值 ± 标准误)。不同小写字母表示不同花朝向存在显著差异(P < 0.05)。

Fig. 2 Comparison of visit duration per flower (A) and visit frequency (B) of Apis cerana to three orientations of Prunus mume f. purpurea (mean ± SE). Different lowercase letters indicate significant differences among different flower orientations (P < 0.05).

图3 中华蜜蜂访问朱砂梅3种朝向花的一次移出花粉量(A)和一次落置花粉量(B)比较。所有箱线图均基于原始数据(实心点)绘制, 显示了均值(三角形)、中位数(中间横线)、四分位距(箱体上边缘), 1.5倍四分位距(须线)和异常值。不同小写字母表示不同花朝向存在显著差异(P < 0.05)。

Fig. 3 Comparison of pollen removal per visit (A) and pollen deposition on the stigmas per visit (B) by Apis cerana to three orientations of Prunus mume f. purpurea. All panels display box plots based on raw data (solid dots), indicating the mean (triangles), median (horizontal lines), interquartile range (the upper and lower edges of the box), 1.5 times the interquartile range (whiskers) and outliers. Different lowercase letters indicate significant differences among different flower orientations (P < 0.05).

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