| 摘要: |
| 【目的】探究不同番石榴（Psidium guajava Linn.）种质间的花粉形态差异，为番石榴的杂交育种和系统分类工作提供孢粉学依据。【方法】以来自中国、泰国和巴西的27个番石榴种质花粉为试验材料，通过扫描电镜观察其超微结构并测花粉粒极轴长度(LP)、赤道轴长度(LE)、花粉大小（LP×LE）、极赤比（LP/LE）、萌发沟长度（单面）和萌发沟宽度，对不同种质各指标数据进行比较，并采用组间连接法进行系统聚类分析。【结果】27个番石榴种质花粉粒以单粒形式存在，呈辐射对称，极面观为近圆形或近三角形，有明显三孔沟，具角萌发孔，赤道面观均为椭圆形，外壁纹饰均为瘤状纹饰。27个番石榴种质的花粉大小为11.53（10.06~18.42） μm×14.45（13.45~19.64） μm，均为小型花粉粒；极赤比为0.80（0.73~0.94），其中‘草莓’番石榴的花粉粒形状为近球形，其余26个番石榴种质的花粉粒形状均为扁球形；萌发沟长度为5.51（3.27~9.95） μm，萌发沟宽度为0.78（0.33~1.26） μm；上述指标在不同种质间均存在极显著差异。系统聚类分析结果显示，在平方欧氏距离为2时可将27个番石榴种质分为5个类群，其中‘草莓’番石榴种质单独聚为一类，其花粉的LP、LE、LP×LE、LP/LE均显著大于其他种质。【结论】不同番石榴种质的萌发孔、外壁纹饰和萌发沟数具有遗传保守性，花粉特征具有遗传多样性，其中花粉特征可在一定程度上反映番石榴种质间的差异。 |
| 关键词: 番石榴 花粉形态 花粉特征 种质资源 进化程度 |
| DOI：DOI:10.13207/j.cnki.jnwafu.2024.11.011 |
| 分类号: |
| 基金项目:2022年省级乡村振兴战略专项资金种业振兴项目“番石榴种质资源创制与新品种选育”（2022-NPY-01-005）；广东省农业科学院横向科技项目“番石榴种质创制和配套栽培技术研究”（2022） |
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| Pollen morphology characteristics of 27 Psidium guajava germplasms |
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SHAO Xuehua1, JIANG Haoran2, CHEN Jun3, ZHANG Shoumei4, XIAO Weiqiang1, LAI Duo1, ZHUANG Qingli1, QIN Jian1
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1.Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA)/Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research,Institute of Fruit Tree Research,Guangdong Academy of Agricultural Sciences,Guangzhou,Guangdong 510640,China;2.College of Horticulture and Gardening,Yangtze University,Jingzhou,Hubei 434000,China;3.Research Institute of Fruit Tree Science in Guangzhou City,Guangzhou,Guangdong 510640,China;4.Agricultural and Rural Technical Service Center in Wanqingsha Town,Nansha District,Guangzhou,Guangdong 510640,China
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| Abstract: |
| 【Objective】This study explored the variations of pollen morphology among different Psidium guajava germplasms to provide palynological basis for cross breeding and systematic classification of P. guajava.【Method】A total of 27 P. guajava germplasms were selected from China,Thailand and Brazil.Scanning electron microscope was used to observe pollen ultrastructure and to measure polar axis length(LP),equatorial axis length(LE),pollen size(LP×LE),ratio of polar axis length to equatorial axis length (LP/LE),germination groove length (single surface) and germination groove width.All indicators were compared and the systematic cluster analysis was conducted using the intergroup connectivity method.【Result】Pollen grains of 27 P. guajava germplasms existed in the form of single grains,which were radially symmetrical.The polar plane view showed nearly circular or nearly triangular shapes with obvious three-hole grooves and angular germination holes,the equatorial plane view showed oval shape,and outer wall patterns were all tumor like.The pollen size was 11.53 (10.06-18.42) μm×14.45 (13.45-19.64) μm,and all were small in size grade.The ratio of polar axis length to equatorial axis length (LP/LE) was 0.80 (0.73-0.94).Except for ‘Caomei’ with shape of nearly spherical,other 26 P. guajava germplasms were oblate spherical in shape.The length and width of germination groove were 5.51 (3.27-9.95) μm and 0.78 (0.33-1.26) μm.There were significant differences in above indexes among 27 P. guajava germplasms. Cluster analysis showed that the 27 germplasms could be divided into 5 groups with squared Euclidean distance of 2.‘Caomei’ was gathered into one cluster separately with significantly larger LP,LE,LP×LE and LP/LE than other germplasms.【Conclusion】Germination hole,outer wall pattern and number of germination groove of P. guajava pollen had genetic conservation and pollen characteristics showed genetic diversity.Pollen characteristics reflected the variability among P. guajava germplasms to some extent. |
| Key words: Psidium guajava pollen morphology pollen characteristic germplasm resource evolution degree |
