摘要
【目的】探究抗无乳链球菌良种壮罗1号罗非鱼抗病机制与细菌群落的关系及其在杂交后代中的遗传效应,为通过杂交育种选育兼具快速生长和抗病性状的罗非鱼提供理论依据。【方法】以吉富罗非鱼和壮罗1号罗非鱼为亲本进行自交和杂交,获得吉富自交F_(1)代、壮罗1号自交F_(1)代、吉富×壮罗1号杂交F_(1)代、壮罗1号×吉富杂交F_(1)代。采集4组罗非鱼的鳃和尾鳍组织,对16S rRNA的V3~V4区进行测序,分析不同样本细菌群落结构,采用基于线性判别分析的效应大小分析(LEfSe)筛选不同样本细菌群落间具有显著差异的生物标志物。【结果】Alpha多样性分析结果表明,壮罗1号自交F_(1)代鳃和尾鳍细菌群落的Shannon指数、Shannon even指数和Simpson指数均明显小于吉富自交F_(1)代。壮罗1号×吉富杂交F_(1)代和吉富×壮罗1号杂交F_(1)代的细菌群落多样性也整体较吉富自交F_(1)代明显下降。Beta多样性分析结果表明,壮罗1号×吉富杂交F_(1)代、吉富×壮罗1号杂交F_(1)代的鳃和尾鳍细菌群落组成较接近壮罗1号自交F_(1)代,说明壮罗1号的细菌群落结构具有较好的遗传可继承性。壮罗1号自交F_(1)代、壮罗1号×吉富杂交F_(1)代、吉富×壮罗1号杂交F_(1)代鳃和尾鳍细菌群落中,好氧或兼性厌氧菌栖水菌属(Enhydrobacter)的相对丰度明显高于吉富自交F_(1)代。壮罗1号自交F_(1)代鳃细菌群落中筛选到的生物标志物包含嗜酸菌2013Ark19i。【结论】壮罗1号罗非鱼鳃细菌群落中存在相对丰度较高的需氧菌和嗜酸菌,表明鳃黏液形成了酸性环境,不利于无乳链球菌生长,而需氧菌能通过竞争性耗氧抑制无乳链球菌生长,推测壮罗1号罗非鱼的抗病机制与其细菌群落密切相关,且其细菌群落结构具有可遗传性,使杂交后代具有接近壮罗1号罗非鱼的抗病能力。
【Objective】To explore the relationship between the disease resistance mechanism of the superior breed Zhuangluo No.1 tilapia resistant to Streptococcus agalactiae and the bacterial community,as well as its genetic effect in hybrid offspring,which could provide theoretical basis for the selection and breeding of tilapia with both rapid growth and disease resistance traits through hybrid breeding.【Method】Self-pollination and crossbreeding were carried out using GIFT and Zhuangluo No.1 tilapia as parents to obtain the GIFT inbred F_(1),Zhuangluo No.1 inbred F_(1),GIFT×Zhuangluo No.1 hybrid F_(1),and Zhuangluo No.1×GIFT hybrid F_(1).The gill and tail fin tissues of 4 groups of tilapia were collected.The V3-V4 regions of 16S rRNA were sequenced.The bacterial community structures of different samples were analyzed,and bio‐markers with significant differences among different sameple bacterial communities were screened by linear discriminant analysis effect size(LEfSe).【Result】Alpha diversity analysis revealed that Shannon index,Shannon even index,and Simpson index of the bacterial community in gill and tail fin of Zhuangluo No.1 inbred F_(1) were greatly lower than GIFT inbred F_(1).Accordingly,bacterial community diversity of Zhuangluo No.1×GIFT hybrid F_(1) and GIFT×Zhuangluo No.1 hybrid F_(1) were also lower than GIFT inbred F_(1).Beta diversity analysis indicated that relative abundance of main bacterial community composition of Zhuangluo No.1×GIFT hybrid F_(1) and GIFT×Zhuangluo No.1 hybrid F_(1) was close to that of Zhuangluo No.1 inbred F_(1),suggesting heritable bacterial community in Zhuangluo No.1.The relative abundance of the aerobic and facultative anaerobic bacteria Enhydrobacter in the gill and tail fin of Zhuangluo No.1 inbred F_(1),Zhuangluo No.1×GIFT hybrid F_(1) and GIFT×Zhuangluo No.1 hybrid F_(1) were greatly higher than GIFT inbred F_(1),including a remarka-ble biomarker acidophile 2013Ark19i was identified in the of Zhuangluo No.1.inbred gill bacterial community.【Conclu‐sion】The gill bacterial community of Zhuangluo No.1 tilapia contains a relatively high abundance of aerobic and acido‐philic bacteria,indicating that the gill mucus creates an acidic environment that is not conducive to the growth of Strepto‐coccus agalactiae.However,aerobic bacteria can inhibit the growth of Streptococcus agalactiae through competitive oxy‐gen consumption.It is speculated that the disease resistance mechanism of Zhuangluo No.1 tilapia is closely related to its bacterial community,and the structure of its bacterial community is hereditary,enabling the hybrid offspring to have di-sease resistance close to that of Zhuangluo No.1 tilapia.
作者
刘奕
吴昊天
陈丽婷
严欣
肖俊
陆颖
LIU Yi;WU Hao-tian;CHEN Li-ting;YAN Xin;XIAO Jun;LU Ying(Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources,Ministry of Education(Shanghai Ocean University),Shanghai 201306,China;Key Laboratory of Freshwater Aquatic Genetic Resources,Ministry of Agricul‐ture and Rural Affairs(Shanghai Ocean University),Shanghai 201306,China;Guangxi Academy of Fishery Sciences/Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture,Nanning,Guangxi 530021,China)
出处
《南方农业学报》
北大核心
2025年第6期1813-1822,共10页
Journal of Southern Agriculture
基金
国家重点研发计划项目(2022YFD2400804)
广西水产遗传育种与健康养殖重点实验室自主研究课题(2024-A-01-01)
广西农业科技自筹经费项目(Z202279,Z202291)。
关键词
罗非鱼
无乳链球菌
细菌群落
抗病
16S
rRNA测序
tilapia
Streptococcus agalactiae
bacterial community
disease resistance
16S rRNA sequencing
