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林业科学 ›› 2021, Vol. 57 ›› Issue (7): 61-69.doi: 10.11707/j.1001-7488.20210707

• 论文与研究报告 • 上一篇    下一篇

海南油茶的倍性鉴定

叶天文1,袁德义1,李艳民1,肖诗鑫1,*,龚守富2,张健2,李素芳1,罗健3   

  1. 1. 中南林业科技大学 经济林培育与保护教育部重点实验室 长沙 410004
    2. 信阳农林学院 信阳 464000
    3. 海南澄迈乐香种苗管理有限公司 澄迈 571900
  • 收稿日期:2020-09-24 出版日期:2021-07-25 发布日期:2021-09-02
  • 通讯作者: 肖诗鑫
  • 基金资助:
    国家重点研发计划课题"木本油料重要性状形成与调控"(2018YFD1000603)

Ploidy Identification of Camellia hainanica

Tianwen Ye1,Deyi Yuan1,Yanmin Li1,Shixin Xiao1,*,Shoufu Gong2,Jian Zhang2,Sufang Li1,Jian Luo3   

  1. 1. Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education Central South University of Forestry and Technology Changsha 410004
    2. Xinyang Agriculture and Forestry University Xinyang 464000
    3. Lexiang Seedling Management Limited Company in Chengmai, Hainan Chengmai 571900
  • Received:2020-09-24 Online:2021-07-25 Published:2021-09-02
  • Contact: Shixin Xiao

摘要:

目的: 海南油茶的花、果特征和生长发育习性与其他油茶存在明显差异,其倍性尚不清楚。本研究采用流式细胞术和染色体计数法,旨在阐明海南油茶的倍性,为海南油茶授粉树配置和遗传育种研究提供科学依据。方法: 首先,以二倍体大花窄叶油茶作为对照,采集60份海南油茶优株的嫩叶为试材,利用流式细胞仪检测每个样本的DNA含量的荧光强度,根据试材与对照DNA峰值的比值估算样本的倍性;其次,根据流式细胞仪鉴定的结果,以二倍体大花窄叶油茶作为对照,选取34份不同地区不同倍性的海南油茶代表材料,进行根尖染色体制片,在光学显微镜下进行染色体计数,验证对照和试材的流式细胞术检测结果。结果: 流式细胞术检测结果表明:对照二倍体大花窄叶油茶的峰值为50.39,供试的60份海南油茶中,8份峰值范围是205.50~213.42,与对照的峰值相比为八倍体,50份峰值范围是243.16~256.11,与对照的峰值相比为十倍体,另外CMZX-612和TCXYL-61峰值分别是177.09和188.02,与对照的峰值相比疑似为七倍体;同时各样品峰值的变异系数大部分都在5%以内。进一步的染色体计数结果表明:二倍体大花窄叶油茶染色体数为2n=2x=30,供试的34份海南油茶中,8份材料为八倍体(2n=8x=120),其中包括流式细胞术估测疑似为七倍体的CMZX-612和TCXYL-61,这2份材料经根尖细胞染色体计数(2n=8x=120)确认实际也为八倍体;26份材料为十倍体(2n=10x=150),染色体计数结果与流式细胞术估测结果基本一致。结论: 流式细胞术检测和染色体计数共同表明:供试的60份海南油茶为八倍体(2n=8x=120)和十倍体(2n=10x=150)2种倍性,其中十倍体占83.3%;海南油茶作为山茶属新发现的一个种,其倍性与其他油茶存在明显差异。海南油茶倍性的确定,可为后续海南油茶的种质资源鉴定、杂交亲本选配以及油茶多倍体的遗传进化等研究奠定基础。

关键词: 海南油茶, 倍性, 染色体, 流式细胞术

Abstract:

Objective: The flower and fruit characteristics, growth and development habits of Camellia hainanica are obviously different from other Camellia species, and its ploidy is still unclear. This study uses flow cytometry and chromosome counting to clarify the ploidy of C. hainanica, which provides a basis for deployment of pollen trees and studies of genetics and breeding in the future. Method: Firstly, diploid Camellia fluviatilis var. megalantha was used as a control, and young leaf samples of 60 elite trees of C. hainanica were collected, fluorescence intensity of the DNA content of each sample was measured by flow cytometry(FCM), the ploidy of samples was estimated according to their DNA peaks. Secondly, according to the results of flow cytometry, diploid C. fluviatilis var. megalantha was used as a control, a total of 34 representative trees were selected, including different ploidy C. hainanica from different regions, and samples of root tips were collected for counting their chromosome numbers using electron microscope, so as to verify the results of flow cytometry. Result: The detection by flow cytometry showed that: The DNA peak of diploid C. fluviatilis var. megalantha was 50.39. Among the 60 samples of C. hainanica, 8 samples showed a range of DNA peak of 205.50-213.42, indicating an octoploid compared to the control, and 50 samples showed a DNA peak range of 243.16-256.11, indicating a decaploid. The DNA peaks of CMZX-612 and TCXYL-61 were 177.09 and 188.02, doubted to be a heptaploid. The coefficient of variation of the DNA peaks was less than 5% for most of the tested samples. And the chromosome counting showed that: The chromosome number of diploid C. fluviatilis var. megalantha was 2n=2x=30. Among the 34 samples of C. hainanica for testing, 8 root tip samples were octoploid(2n=8x=120), including CMZX-612 and TCXYL-61 doubted to be heptaploid detected by the flow cytometry, chromosome counting confirmed that they are actually octoploid(2n=8x=120). 26 root tip samples of C. hainanica were decaploid(2n=10x=150) detected by the chromosome counting, basically the same as those estimated by flow cytometry. Conclusion: The flow cytometry and chromosome counting both indicated that the 60 tested samples of C. hainanica had two ploidies, octoploid(2n=8x=120) and decaploid(2n=10x=150), of which decaploid accounted for 83.3%. C. hainanica is a newly discovered species of the genus Camellia, and its ploidy is obviously different from other species in Camellia. Determination of ploidy of C. hainanica provides a significant basis for further studies on inheritance and evolution of polyploidy, as well as parents selection for cross breeding and identification of germplasm resources.

Key words: Camellia hainanica, ploidy, chromosome, flow cytometry

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