中国农业科学 ›› 2020, Vol. 53 ›› Issue (3): 585-599.doi: 10.3864/j.issn.0578-1752.2020.03.011

• 园艺 • 上一篇    下一篇

柑橘不同类型砧木的种子和苗期性状

朱世平1,王福生1,陈娇2,3,余歆1,余洪1,罗国涛1,胡洲1,冯锦英1,赵晓春1,洪棋斌1()   

  1. 1 西南大学/中国农业科学院柑桔研究所/国家柑桔工程技术研究中心,重庆 400712
    2 西南大学园艺园林学院,重庆 400716
    3 四川省富顺县农业农村局,四川富顺 643200
  • 收稿日期:2019-07-09 接受日期:2019-09-19 出版日期:2020-02-01 发布日期:2020-02-13
  • 通讯作者: 洪棋斌
  • 作者简介:朱世平,E-mail:zhushiping@cric.cn。
  • 基金资助:
    国家重点研发计划(2018YFD0201503);现代农业产业技术体系项目(CARS-26);中央高校基本业务费(XDJK2016B024);国家柑桔工程技术研究中心开放课题资助项目、重庆市现代山地特色高效农业技术体系创新团队建设计划晚熟柑桔脆李技术体系、西南大学双一流学科建设项目、西南大学博士/引进人才计划基金(SWU117038)

Seed Traits and Seedling Performances of Different Types of Citrus Rootstock

ZHU ShiPing1,WANG FuSheng1,CHEN Jiao2,3,YU Xin1,YU Hong1,LUO GuoTao1,HU Zhou1,FENG JinYing1,ZHAO XiaoChun1,HONG QiBin1()   

  1. 1 Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences/ National Citrus Engineering Research Center, Chongqing 400712
    2 College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716
    3 Bureau of Agriculture and Rural Affairs of Fushun County, Fushun 643200, Sichuan
  • Received:2019-07-09 Accepted:2019-09-19 Online:2020-02-01 Published:2020-02-13
  • Contact: QiBin HONG

摘要:

【目的】优良的砧木能促进果树生长、提高果实产量和品质、增强植株的抗逆性和适应性。目前我国柑橘生产上使用的砧木品系混杂,生长参差不齐,抗逆性差异明显,严重影响了苗木质量。通过对各种种质类型柑橘砧木的连续多年评价,分析不同遗传种质砧木的种子和苗期特征,鉴定影响砧木苗木质量的关键性状,建立规范柑橘砧木的评价标准,为筛选优良砧木单系提供指导。【方法】以104份柑橘砧木种质为材料,连续5年评价单果种子数、种子饱满度、千粒重和胚型等种子性状及播种后的出苗率、黄化率、立枯率、株高和茎粗等苗期性状,并对这些指标进行相关性、主成分分析以及不同年份间的变异系数分析。利用保守的直系同源序列(conserved ortholog sequences,COS)分子标记技术评价部分不同胚型砧木种质幼苗遗传背景的一致性,分析部分种质中微型反向重复转座元件(miniature inverted-repeat transposable element,MITE)片段插入与胚型的关联性。【结果】(1)枳、枳杂种和香橙的果实为多核和较多核,种子为混胚和多胚,种子饱满,大部分材料的种子千粒重为200 g以上;而宽皮柑橘为少核、较多核和多核,多胚,种子中等饱满,约一半种质的种子千粒重为100 g以下。(2)在苗期特性方面,香橙出苗率最高,黄化率较低,其幼苗对立枯病比较敏感;枳及其杂种的出苗率较高,黄化率也较高,但耐立枯病;宽皮柑橘的出苗率则较低,幼苗发生黄化和立枯的比例也比较低。比较播种后10个月内的幼苗生长势,枳的生长势最强,其次是枳杂种和香橙,而宽皮柑橘的生长势最弱。(3)对种子和苗期性状指标的相互关系及主成分分析结果表明,除黄化率和立枯率外,单果种子数、千粒重、饱满度、单胚比例、多胚比例、胚型、出苗率、幼苗株高和茎粗等指标之间具有极显著(P<0.01)或显著(P<0.05)的相关性,且不同指标对主成分的方差贡献率有明显差异。通过主成分分析能够清楚地区分枳、枳杂种、香橙、宽皮柑橘及其他砧木的种质类型。除黄化率外,种子性状和苗期表现的指标在不同年份间的变异系数相对较低,说明这些性状较为稳定。(4)COS分子标记结果显示,单胚宽皮柑橘幼苗的变异程度比单胚枳及其他多胚或混胚类型种质的变异程度高;在单胚的柚和宽皮柑橘等种质中没有MITE片段的插入,而在多胚的香橙、宽皮柑橘、枳杂种等种质中有插入,但是在枳种质中无论是单胚还是多胚均没有检测到MITE片段的插入。【结论】柑橘砧木种子性状和幼苗性状指标之间高度相关,通常种子性状优异的砧木种质,其幼苗质量也较好。枳的种子和幼苗(播种后10个月)综合性状最好,其次是枳杂种和香橙,宽皮柑橘的种子和苗期综合性状最差。

关键词: 柑橘砧木, 种子性状, 胚型, 出苗率, 一致性

Abstract:

【Objective】Good rootstock could promote plant growth, improve fruit yield and quality, and enhance stress tolerance and adaptability. Currently in China, mixed genotype of seeds is generally used for propagation of nursery trees. Variable germination, growth, and stress tolerance of seedlings are the common problems significantly affecting the quality of nursery trees, also the performance of orchard plants. This research was aimed to study the key parameters related to the quality of seedlings in different genotypes of rootstocks, to establish the standards for evaluation of rootstock and provide guidelines for selection of superior rootstock. 【Method】 104 different citrus rootstock germplasm accessions were evaluated in five consecutive years on their seed characteristics, such as seed number per fruit, plumpness of seeds, 1 000-grain weight, embryonic type, and the seedling performances, such as germination rate, occurrence of etiolation and blight, and the growth vigor. The uniformity of the seedlings of some rootstock accessions were identified by COS (Conserved Ortholog Sequences) markers. Association of MITE (Miniature inverted-repeat transposable element) insertion with embryonic type was also investigated in some rootstock accessions. 【Result】 (1) Fruits of Poncirus and its hybrids, as well as Citrus junos accessions were highly multi-seeded and multi-seeded. Most of the seeds were plumpy, polyembryonic and mixed-embryonic type. The 1000-grain weight of most accessions was more than 200 g. The seed numbers per fruit in mandarins were highly variable in the range of low-seeded, multi-seeded and highly multi-seeded. Most seeds were medium plumpy and polyembryonic. The 1 000-grain weight in approximately half of the mandarin accessions was less than 100 g. (2) Seedling performances differed among different types of rootstocks. C. junos demonstrated the highest frequency of germination, and lower etiolation rate, but the seedlings were sensitive to blight disease. The germination rates of Poncirus and its hybrids were lower than that of C. junos, but the etiolation rate was higher. Their seedlings were tolerant to blight disease. The germination rates of most mandarin accessions were comparatively low, and the rates of both etiolation and blight were also low. Comparisons of seedling growth at 10 months after sowing, Poncirus showed the strongest growth vigor, followed by its hybrids and C. junos, while those of mandarins were the least measured by both seedling height and stem diameter. (3) Correlation analysis revealed that except for the occurrences of etiolation and blight, parameters between the traits of seeds and seedlings such as seeds per fruit, 1000-grain weight, plumpness, the mono-embryo rate, poly-embryo rate, embryonic type, the height and the stem diameter of seedlings were tightly correlated at the levels of high significance (P<0.01) or significance (P<0.05). The contribution of each individual parameter to the overall variation was highly different. PCA (principle component analysis) could clearly distinguish the genetic differences between the different types of rootstocks. The coefficient variations of the parameters except for etiolation rate were not significantly variable among different years, indicating those traits were comparatively stable. (4) Results of COS marker showed that mono-embryonic seedlings of mandarin were less uniform than that of mono-embyonic seedlings of Poncirus and all the poly-embryonic and mixed-embyonic accessions. MITE insertion was detected in polyembryonic accessions of mandarin, C. junos and Poncirus hybrids, but did not in monoembryonic accessions of mandarin and pummelo. However, MITE insertion did not observed either in monoembryonic or polyembryonic accessions of some Poncirus. 【Conclusion】Parameters between seed traits and seedling performances were highly correlated. These results indicated that the high quality of seedling was greatly associated with good characters of seed. Measured by overall performance, the characters of both seeds and seedlings of Poncirus were the best, followed by Poncirus hybrids and C. junos, those of mandarins were the worst.

Key words: citrus rootstock, seed trait, embryonic type, seedling performance, uniformity