钙、镁、钾浓度及光照、温度对西番莲花粉离体萌发的影响

蔡昭艳1,苏伟强1a,董 龙1,邱文武1,施平丽1,刘业强1,黄辉晔2,黄章保1,任 惠1,王小媚1*

1广西壮族自治区农业科学院园艺研究所,南宁 530007;2广西壮族自治区农业科学院植物保护研究所,南宁 530007)

摘 要:【目的】探讨培养基中的钙、镁、钾浓度及光照、温度对西番莲花粉体外萌发及花粉管生长的影响。【方法】设置钙、镁、钾及光照、温度梯度,测量在该梯度下的花粉萌发率及花粉管延伸长度。【结果】钙、镁、钾非西番莲花粉离体萌发的必需培养基成分,钙对西番莲花粉离体萌发及花粉管生长具有显著影响,在质量浓度为0~300 mg·L-1时,萌发率及花粉管长度均随浓度的增加而显著增加,在300~1200 mg·L-1时最佳,大于1200 mg·L-1时,萌发率及花粉管长度均显著降低。镁、钾对花粉萌发及花粉管生长均无显著影响。光照、温度对花粉萌发及花粉管生长均具有显著影响,黑暗条件下最佳,随着光照度的增加,萌发率及花粉管长度均显著降低;二次方程能较好地拟合温度对花粉萌发及花粉管生长的影响。【结论】培养基中钙浓度及光照、温度对西番莲花粉体外萌发及花粉管生长具有显著影响,镁、钾无显著影响,最适的Ca(NO32·4H2O质量浓度为300~1200 mg·L-1,西番莲花粉离体萌发的最适培养基为150 g·L-1蔗糖+150 g·L-1 PEG-4000+25 mg·L-1 H3BO3+300~1200 mg·L-1 Ca(NO32·4H2O,在该培养基组分下的花粉萌发率为86%以上。0 lx(黑暗)、25.69 ℃分别为西番莲花粉萌发及花粉管生长的最适光照及温度,温度对西番莲花粉萌发及花粉管生长的影响符合二次项方程。

关键词:西番莲;花粉;离体萌发;培养基;光照;温度

西番莲又名百香果,为西番莲科(Passifloraceae)西番莲属(Passiflora Linn.)植物[1],因具有“短、平、快”的特点,近年来西番莲产业发展迅猛[2],但由于受到栽培条件及气候因素的影响,西番莲产量低、经济效益差等问题日益突出,成为制约产业持续发展的重要原因,西番莲的开花坐果已成为研究的热点[3-5]。西番莲完成授粉受精,在果实中形成种子,后在包裹种子的假种皮中产生果汁,是西番莲成功坐果并获得果汁的前提,花粉是植物的雄配子体,是参与授粉受精的重要元件,大量有活力的花粉传粉至柱头并顺利萌发,是完成授粉受精的前提和基础,因此花粉活力的测定成为育种及栽培工作的重要内容[6]。花粉活力检测的方法主要有TTC 染色法、醋酸洋红染色法、I2-KI染色法、过氧化物酶染色法,但染色法得到的结果与花粉真正的活力存在较大的误差[7-8],花粉离体萌发被认为最接近花粉在柱头上的萌发,是检测花粉活力最简单、直接、可靠的方法[9]

前人对西番莲花粉离体萌发做了一定的研究,李红曦等[10]在离体培养基中添加PEG-3500,将紫果西番莲花粉离体培养的萌发率提高到68.7%,蔡昭艳等[11]探讨了培养基中的蔗糖、硼酸及PEG-4000对西番莲花粉体外萌发的影响,并通过正交试验将西番莲花粉的离体萌发率进一步提高。前人对西番莲花粉离体萌发的研究取得了一定的进展,为进一步研究西番莲花粉离体萌发提供了基础,但研究主要集中在培养基的蔗糖、硼酸、聚乙二醇(PEG)等的浓度对花粉萌发及花粉管的影响方面[12],而花粉离体萌发除了受到以上这些因素的影响外,还受到培养基中的钙、镁、钾浓度及光照、温度等培养条件的影响[13-14],相关研究还未见报道。

西番莲为多年生藤本植物,不同的品种开花季节不同,有些品种可周年开花,加之绝大多数栽培种的西番莲开花时间在11:00到16:00之间,是一天中气温最高的时间,气温可达40 ℃以上,即西番莲的开花坐果受到一年四季高温、低温天气的影响,温度为影响西番莲坐果的主要气候因素,因此研究温度对花粉萌发及花粉管生长具有重要的意义。笔者在本研究中以西番莲的主栽品种台农一号新鲜花粉为试验材料,研究培养基中的钙、镁、钾浓度及温度、光照对西番莲花粉离体萌发的影响,进一步优化西番莲花粉离体萌发培养基组分,找出最适合的光照、温度条件,并量化温度对西番莲花粉萌发的影响,为进一步揭示温度对西番莲坐果的影响提供参考。

1 材料和方法

1.1 材料

本试验于2020年9—11月在广西壮族自治区农业科学院园艺研究所试验基地(22.85°N,108.24°E)进行,试验期间当地的最高气温为37 ℃,最低气温为22 ℃,以当年栽种的中国西番莲主栽品种台农一号西番莲(Passiflora caerulea L.‘Tainong No.1’)盛花期花朵刚开放时的新鲜花粉为试验材料,在正常生长的10 株西番莲上每株采集2 朵饱满的花朵,共计20朵花,将采下的花朵放进纸袋中并迅速带回实验室,在开有25 ℃空调的实验室中将花药用镊子轻轻取下,花粉朝上置于铺有称量纸的培养皿中,称量纸下铺有干燥的硅胶。将培养皿置于通风干燥处约2 h,待花药充分开裂、花粉较干燥时用软毛笔轻轻扫下花粉,把所有的花粉扫下后用毛笔轻轻混合均匀备用。

1.2 方法

1.2.1 试验设置 以成分为150 g·L-1蔗糖+150 g·L-1 PEG-4000+ 25 mg · L-1 H3BO3+300 mg · L-1 Ca(NO3)2·4H2O+200 mg·L-1 MgSO4·7 H2O+100 mg·L-1 KNO3的培养基为基础培养基。试验分别设置以下处理:Ca(NO3)2·4H2O 含量(ρ,后同)设定6 个梯度:0、100、300、600、1200、2400 mg·L-1;MgSO4·7 H2O含量设定6个梯度:0、200、400、800、1600、3200 mg·L-1,KNO3含量设定6个梯度:0、100、200、400、800、1600 mg·L-1。光照度设定4个梯度:0(黑暗)、600、1150、2210 lx;温度设置9个梯度:5、10、15、20、25、30、35、40、45 ℃。每个处理设置3次重复。

1.2.2 花粉培养 花粉培养采用液体培养基培养方法,具体方法为:用移液枪在直径为6 cm 的培养皿中加入3.5 mL的液体培养基,轻轻摇晃使培养液均匀分布形成液体薄层,将培养皿放置于预先设置好温度及光照条件人工气候箱中,待培养皿中的培养液达到设定的温度后,用软毛笔蘸取适量花粉撒播于培养皿中,使花粉在液体培养基中均匀分布。钙、镁、钾浓度梯度试验均在黑暗、25 ℃下进行培养,光照梯度试验的培养温度为25 ℃,温度梯度试验在黑暗条件下培养,所有试验的培养时间均为4 h。

1.2.3 花粉萌发率及花粉管长度的测量 将人工气候箱中的培养皿放进4 ℃的冰箱中冷藏保存,待观察时取出,培养皿恢复室温后用纸巾擦拭干净培养皿底部的水,以免影响观察时视野的清晰度。在奥林巴斯X53 40 倍显微镜下统计测量花粉的萌发率和花粉管的长度,每个重复在培养皿的不同位置共观察5个视野,每个视野的花粉数量不少于20粒,3个重复共15个视野,每个处理共观察的花粉数量不少于300 粒,并拍照,用CellSens standars 软件中“测量”-“折线”的方法测量花粉管的长度。以花粉管长度大于等于花粉粒直径视为花粉萌发,并统计花粉管长度及花粉萌发率,萌发率/%=萌发花粉粒数/总观察花粉粒数×100;花粉管长度=测量得到的所有花粉管总长度(μm)/花粉粒数。

1.2.4 数据处理 采用SPSS 17.0 软件对钙、镁、钾及光照、温度对西番莲花粉离体萌发的影响试验所得数据进行单因素方差分析,用Duncan法进行多重比较。采用SPSS17.0 曲线估计中的“对数”“二次项”“三次项”对温度对西番莲花粉离体萌发影响的数据进行分析及曲线拟合,根据p 值及R2值来确定最佳拟合模型,并量化温度产生的影响。使用拟合的方程式预算出花粉萌发及花粉管生长的最低温度(Tmin)、最适温度(Topt)及最高温度(Tmax)。

2 结果与分析

2.1 培养基中的钙、镁、钾对西番莲花粉萌发及花粉管生长的影响

2.1.1 钙 钙非西番莲花粉体外萌发的必需物质,西番莲花粉在不含钙的液体培养基中仍能萌发,但钙浓度对花粉萌发率及花粉管的生长均具有显著的影响,在Ca(NO32·4H2O 质量浓度为0~300 mg·L-1时,花粉萌发率及花粉管长度均随着Ca(NO32·4H2O浓度的增加而增加,在质量浓度为300~1200 mg·L-1时,花粉萌发率均超过86%,在此浓度区间内花粉萌发率及花粉管长度没有显著差异。当质量浓度增加到2400 mg·L-1时,花粉萌发率及花粉管长度均显著降低。由此液体培养基中的Ca(NO32·4H2O质量浓度为300~1200 mg·L-1时适合西番莲花粉的体外萌发及花粉管伸长(表1)。

表1 培养基中的钙浓度对西番莲花粉体外萌发及花粉管生长的影响
Table 1 Effects of calcium concentration in medium on pollen germination and pollen tube elongation length of Passiflora in vitro

注:不同小写字母表示在p <0.05 差异显著,不同大写字母表示在p <0.01 差异极显著。下同。
Note: Different small letters indicate significant difference at p <0.05, different capital letters indicate extremely significant difference at p <0.01.The same below.

花粉管长度Pollen tube elongation length/μm 167.52±1.25 D 185.34±1.07 C 224.35±0.95 A 225.62±1.20 A 225.46±1.57 A 195.36±0.83 B水平Level/(mg·L-1)0 100 300 600 1200 2400萌发率Germination rate/%27.86±0.56 d 39.79±0.42 c 86.65±0.39 a 87.16±0.57 a 86.21±0.52 a 52.34±0.31 b

2.1.2 镁 试验表明,镁非西番莲花粉体外萌发的必需物质,西番莲花粉在不含镁的液体培养基中仍能萌发,且在本试验浓度范围内对花粉体外萌发率及花粉管的生长均无显著影响(表2)。

表2 培养基中的镁浓度对西番莲花粉体外萌发及花粉管长度的影响
Table 2 Effects of magnesium concentration in medium on pollen germination and pollen tube elongation length of Passiflora in vitro

水平Level/(mg·L-1)0 200 400 800 1600 2400萌发率Germination rate/%87.45±0.56 a 87.82±0.71 a 88.06±0.95 a 87.85±0.45 a 87.68±0.23 a 88.12±0.59 a花粉管长度Pollen tube elongation length/μm 224.52±2.35 A 225.34±1.56 A 224.35±2.48 A 225.62±0.69 A 224.46±2.15 A 223.36±1.51 A

2.1.3 钾 钾非西番莲花粉体外萌发的必需物质,西番莲花粉在不含钾的液体培养基中仍能萌发,且在本试验浓度范围内对花粉体外萌发率及花粉管的生长均无显著影响(表3)。

表3 培养基中的钾浓度对西番莲花粉体外萌发及花粉管长度的影响
Table 3 Effects of potassium concentration in medium on pollen germination and pollen tube elongation length of Passiflora in vitro

水平Level/(mg·L-1)0 100 200 400 800 1600萌发率Germination rate/%88.51±0.75 a 89.12±0.58 a 89.25±0.92 a 88.89±0.65 a 89.36±0.27 a 88.73±0.49 a花粉管长度Pollen tube elongation length/μm 189.52±1.02 A 191.20±0.96 A 190.49±1.32 A 189.41±1.59 A 200.34±0.45 A 201.14±0.59 A

2.2 光照、温度对西番莲花粉萌发及花粉管生长的影响

2.2.1 光照 光照对西番莲花粉体外萌发具有显著影响(表4),花粉在0 lx(黑暗)的条件下萌发率最高,花粉管生长最佳。在本实验设置的光照度范围内,随着光照度的增加花粉萌发率及花粉管长度均显著下降。光照度为2210 lx时的花粉萌发率为0 lx时的43.34%。且出现部分花粉管扭曲及变形(图1)。

图1 花粉在不同光照度下的萌发及花粉管长度
Fig.1 Pollen germination and tube elongation length in different illumination

表4 光照度对西番莲花粉体外萌发及花粉管长度的影响
Table 4 Effects of illumination on pollen germination and pollen tube elongation length of Passiflora in vitro

水平Level/lx 0 610 1150 2210萌发率Germination rate/%86.62±0.56 a 65.23±0.72 b 45.56±0.95 c 37.54±0.24 d花粉管长度Pollen tube elongation length/μm 219.52±0.56 A 181.20±0.79 B 170.49±0.24 C 159.41±0.53 D

2.2.2 温度 将温度对西番莲花粉体外萌发率及花粉管生长的数据进行单因素方差分析,结果(表5)表明,温度对花粉萌发率及花粉管的生长均具有显著影响,在5 ℃时花粉无萌发,后随着温度的上升,花粉萌发率及花粉管长度均显著增加,当温度达到25 ℃时,花粉萌发率及花粉管长度均达到最高,之后随着温度的升高,花粉萌发率及花粉管长度均显著降低,当温度为45 ℃时,花粉无萌发。对萌发率及花粉管生长SPSS 线性及曲线估计进行曲线拟合(图2),发现二次项方程能对萌发率及花粉管长度进行较好的拟合,p值均为0.000<0.05,均达到显著水平,萌发率及花粉管的R2分别为0.95和0.98,花粉萌发率拟合方程式为:y=-0.21x2+10.78x-58.71,花粉管生长的拟合方程式为:y=-0.56x2+28.38x-124.52,用方程式预测花粉萌发及花粉管生长的基本温度,Topt为花粉萌发或花粉管生长的最适温度,Tmin为花粉开始萌发或花粉管生长的最低温度,Tmax为最高温度。由表6 可见,台农一号西番莲花粉萌发的温度范围为6.19~45.13 ℃,最适温度为25.69 ℃,在此温度下的萌发率为79.63%。花粉管生长的温度范围为4.85~45.55 ℃,最适温度为25.34 ℃,在此温度下的花粉管长度为235.04 μm,花粉在各温度下的萌发及花粉管生长见图3。

图2 花粉萌发率及花粉管长度对温度响应的曲线拟合
Fig.2 The fitting curve of pollen germination rate and pollen tube length in response to temperature

A.温度对花粉萌发率影响曲线拟合;B.温度对花粉管长度影响曲线拟合。
A.The fitting curve of pollen germination rate in response to temperature;B.The fitting curve of pollen tube elongation length in response to temperature.

图3 西番莲花在不同培养温度下的花粉体外萌发及花粉管生长情况
Fig.3 Pollen germination and pollen tube growth in different culture temperatures

表5 培养温度对西番莲花粉体外萌发及花粉管长度的影响
Table 5 Effects of temperature on germination and pollen tube elongation length of Passiflora in vitro

水平Level/℃5 10 15 20 25 30 35 40 45萌发率Germination rate/%0.00±0.00 h 16.35±0.58 g 48.83±0.32 e 79.31±0.39 b 87.15±0.43 a 75.51±0.74 c 59.44±0.62 d 35.15±0.52 f 0.00±0.00 h花粉管长度Pollen elongation tube length/μm 0.00±0.00 H 114.62±1.02 G 175.62±0.85 E 195.26±0.51 B 246.24±0.65 A 216.25±0.87 C 175.26±0.58 D 132.35±0.45 F 0.00±0.00 H

表6 对温度响应数据的拟合方程常数及最大萌发率、花粉管长度及预算最适、最低、最高温度
Table 6 Maximum pollen germination rate and pollen tube length(PTL),equation constants and cardinal temperatures for pollen germination in response to temperature

性状Character最大萌发率及花粉管长度Maximum pollen germination rate and PTL基本温度Cardinal temperature/℃方程式常数Equation constants a-0.21-0.56 b c R2 Topt Tmin Tmax花粉萌发率Pollen germination rate/%花粉管长度Pollen tube length/μm 79.63 235.04 10.79 28.38-58.71-124.52 0.95 0.98 25.69 25.34 6.19 4.85 45.13 45.55

3 讨 论

笔者在本研究中发现,钙对西番莲花粉的萌发和花粉管生长均具有显著的促进作用,而镁、钾对花粉萌发和花粉管生长无显著影响,Ca(NO3)2·4H2O质量浓度为300~1200 mg·L-1时,萌发率及花粉管长度均最高,萌发率超过86%,浓度过低或过高均对花粉萌发及花粉管生长产生不利影响,这与在草莓[15]、蜡梅[16]中的研究一致。在烟草[17]、枸杞[18]中的研究表明,花粉中含有少量的钙,这可能是花粉在不含有钙的培养基中仍能少量萌发的原因。花粉授粉到柱头之后,柱头会分泌大量的钙,并且在胚囊中也含有大量的钙,钙被认为在花粉萌发及吸引花粉管向胚囊生长中起重要作用[17,19]。本试验中西番莲花粉在不含钙的培养基中仍有27.86%的萌发率,但在培养基中添加钙可极显著提高花粉萌发率及花粉管的生长,这与前人的研究结果相同。前人的研究表明,蜡梅花粉的最适Ca2+质量浓度(换算Ca2+质量浓度)为3.8 mg·L-1 [16],百合花粉的最适Ca2+质量浓度为7.2~10.8 mg·L-1[20],日本海棠花粉的最适Ca2+质量浓度为67.8 mg·L-1 [9],研究培养基中的Ca2+质量浓度在50.8~203.2 mg·L-1时最适合西番莲花粉萌发及花粉管生长,可见不同作物花粉离体萌发所需的钙浓度差异极显著,植物花粉萌发对Ca2+需求的差异可能是植物进化过程中对环境适应的结果,具体的原因有待进一步的探讨。

研究表明温度通过影响花粉萌发率及花粉管生长导致花粉育性降低,是影响坐果的主要原因[21-22],笔者在本研究中发现温度对西番莲花粉萌发亦具极显著影响,这与前人的研究结果相同[23-24]。二次项方程能较好地拟合西番莲花粉萌发率和花粉管生长对温度的响应,并用拟合方程预算出台农一号西番莲花粉离体萌发的温度范围为6.19~45.13 ℃,最适温度为25.69 ℃。不同作物花粉的最适萌发温度差异较大,蜡梅花粉的最适温度为15 ℃[16],海仙花花粉的最适温度为20 ℃[25],猕猴桃的最适温度为30 ℃[26],棉花的最适温度为31.4 ℃[27],花生的最适温度为32 ℃[28]。另外最适温度的高低并不能代表花粉萌发对温度的适应能力,即花粉萌发最适温度高或低的作物在高温或低温下萌发率不一定就高,如本研究中西番莲花粉最适萌发温度为25.69 ℃,其最低萌发温度为6.19 ℃,最高萌发温度为45.13 ℃,最低温度和最高温度之间相差38.94 ℃;而棉花的最适温度为31.40 ℃,其最低萌发温度为15.1 ℃,最高萌发温度为43.3 ℃,最低萌发温度与最高萌发温度之间的跨度为28.20 ℃,可见,西番莲花粉萌发对温度适应性更广。此外,高温/低温下的花粉萌发率与结实率或坐果率具有高度的相关性[29-30],花粉萌发对温度的适应性反映了植物结实或坐果率对温度的适应性。

4 结 论

培养基中的镁、钾对西番莲花粉体外萌发及花粉管生长无显著影响,钙、光照及温度具有显著影响,最适的Ca(NO3)2·4H2O 质量浓度为300~1200 mg·L-1,通过本研究进一步优化,西番莲花粉离体萌发的最适培养基为150 g·L-1蔗糖+150 g·L-1 PEG-4000+25 mg·L-1 H3BO3+300~1200 mg·L-1 Ca(NO3)2·4H2O,在该培养基组分下的花粉萌发率为86%以上。0 lx(黑暗)、25.69 ℃分别为西番莲花粉萌发及花粉管生长的最适光照度及温度,温度对西番莲花粉萌发及花粉管生长的影响符合二次项方程。

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Effects of calcium, magnesium, potassium, light and temperature on pollen germination and pollen tube elongation of passion fruit in vitro

CAI Zhaoyan1, SU Weiqiang1a, DONG Long1, QIU Wenwu1, SHI Pingli1, LIU Yeqiang1, HUANG Huiye2,HUANG Zhangbao1,REN Hui1,WANG Xiaomei1*

(1Institute of Horticultural, Guangxi Academy of Agricultural Sciences, Nanning 530007, Guangxi, China;2Institute of Plant Protection,Guangxi Academy of Agricultural Sciences,Nanning 530007,Guangxi,China)

Abstract:【Objective】Pollen germination in vitro is an important means to detect pollen activity.So far, the effect of calcium, magnesium, and potassium concentrations in the medium, and light and temperature conditions on Passiflora pollen germination and tube elongation are not yet clear, and therefore, the research on these influence factors not only leads to further optimizing the germination conditions, but also provides theoretical guidance for the Passiflora cultivation.【Methods】The experiment was conducted from September to November, 2020 in the Experimental Station (N 22.85°, E 108.24°),Horticulture Institute,Academy of Agricultural Sciences in Guangxi Zhuang Autonomous Region.The maximum temperature during the period was around 37 ℃, and the minimum temperature was 20 ℃.The fresh pollen of Passiflora caerulea L.‘Tainong No.1’as a China’s main variety was used as theexperimental material, the flowers were picked up when they were just opened, and two fully-bloomed flowers were collected from each of the 10 plants.The flowers were put into paper bags and brough to the laboratory immediately.The anther was gently removed in the laboratory with air conditioner of 25 ℃,and placed in a petri dish lined with weighing paper,with dried silica gel under the paper.The petri dish was placed in a ventilated and dry place for about 2 h, until the anthers were fully cracked,and then the pollen grain was swept down gently with a soft brush, mixed with all the pollen for later use.The medium consisted of 150 g·L-1 sugar, 150 g·L-1 PEG-4000, 25 mg·L-1 H3BO3, 300 mg·L-1 Ca(NO3)2·4H2O,200 mg·L-1 MgSO4·7 H2O,and 100 mg·L-1 KNO3was used as a basic medium.0,100,300,600,1200,2400 mg·L-1 of Ca(NO3)2·4H2O and 0,200,400,800,1600,3200 mg·L-1 of MgSO4·7 H2O and 0,100,200,400,800 and 1600 mg·L-1 of KNO3 were set to study the effect of calcium,magnesium and potassium concentrations on pollen germination in vitro under 25 ℃and dark condition.0 lx(dark), 600 lx, 1150 lx and 2210 lx were set to study the effect of illumination under 25 and 5 ℃, 10,15, 20, 25, 30, 35, 40 and 45 ℃were set to study the effect of temperature under dark condition, and each process was set to have three replicates.Liquid medium was used in this study,3.5 mL liquid medium was put into a petri dish with 6 cm in diameter,the petri dish was shaken gently and the liquid medium would distribute evenly to form a thin layer.The petri dish was placed in an artificial climate chamber at preset temperature and under light conditions.Once the temperature equilibrated, a soft brush was used to sprinkle the pollen on the medium and it was incubated for 4 h.Petri dish with germinated pollens were examined under 40× magnification of Olympus microscope BX53, 5 microscopic fields were observed in different positions of the petri dish for each replicate, and the number of pollens in each field was no less than 20,so the number of pollens observed with each treatment was no less than 300.A pollen grain was considered to germinate when the elongation length of the germinated pollen tube was equal to or longer than the diameter of the pollen.The tube elongation length was measured at the end of 4 h incubation with all the treatments using the polyline length measurement tool and expressed in micrometer.The replicated values of pollen germination and tube elongation length from all tests were analyzed using the one-way ANOVA procedure of SPSS 17.0, the Duncan method was used for multiple comparisons,and curve fitting analysis was done using SPSS 17.0 to the data from temperature treatments.【Results】(1) Calcium, magnesium and potassium were not essential components for pollen germination of Passiflora in vitro, because pollen can also germinated in the medium lacking of them,but calcium had significant effects on pollen germination and pollen tube growth of Passiflora in vitro,the optimum concentration was 300-1200 mg·L-1,excessively high or low concentration was not conducive to pollen germination and significantly reduced pollen tube elongation.Magnesium and potassium had no significant effect on pollen germination and pollen tube growth.(2)Light intensity had a significant effect on the pollen germination and tube growth of Passiflora pollen,0 lx was the best light condition,and the germination rate and pollen tube elongation decreased significantly with the increase of light intensity(3)Temperature had a significant effect on pollen germination and pollen tube elongation of Passiflora pollen.It was found that the quadratic equation can fit the germination rate and pollen tube elongation well, with the P value of 0.000<0.05, reaching a significant level, the R2 was 0.95 and 0.98, respectively.The fitting equation of pollen germination rate was as follows:Y =-0.21x2+10.78x-58.71, the fitting equation for pollen tube growth was:Y =-0.56x2 + 28.38x-124.52, and according to the fitting equation,the Tmin(the minimum temperature)of pollen germination was 6.19 ℃,the Topt(the optimum temperature)was 25.69 ℃,and the Tmax(the maximum temperature)was 45.13 ℃.The Tmin of pollen tube growth was 4.85 ℃,the Topt was 25.34 ℃,and the Tmax was 45.55 ℃.【Conclusion】Calcium,light and temperature had significant effects on pollen germination in vitro,but magnesium and potassium had no significant effect.The optimal concentration of calcium was 300-1200 mg·L-1,and the optimal light was 0 lx.The quadratic equation can well fit the effect of temperature on pollen germination rate and pollen tube elongation length in vitro of Passiflora pollen.

Key words:Passiflora;Pollen;In vitro germination;Medium;Light;Temperature

中图分类号:S667.9

文献标志码:A

文章编号:1009-9980(2022)01-0086-09

DOI:10.13925/j.cnki.gsxb.20210092

收稿日期:2021-03-30

接受日期:2021-09-15

基金项目:广西农业科学院基本科研业务费专项(桂农科2020YM30);广西农业科学院科技发展基金项目(桂农科2021JM10);国家现代农业产业技术体系广西特色水果创新团队南宁百香果试验站(nycytxgxcxtd-17-02);广西农业科学院基本科研业务费专项(桂农科2021YT046)

作者简介:蔡昭艳,女,助理研究员,研究方向:热带特色果树育种与生物技术。Tel:15296480409,E-mail:caizhaoyan424@163.com。a为共同第一作者。

*通信作者Author for correspondence.Tel:15078771906,E-mail:wangxiaomei159@163.com