单 位：
南京农业大学无锡渔业学院中国水产科学研究院淡水渔业研究中心/农业部淡水渔业和种质资源利用重点实验室;广东海洋大学水产学院;中国水产科学研究院淡水渔业研究中心
关键词：
吉富罗非鱼;奥利亚罗非鱼;遗传特性;杂交优势;海豚链球菌
摘 要：
以吉富罗非鱼与奥利亚罗非鱼为繁育亲本,采用完全双列杂交繁育4组F1,将初始规格基本一致的4组罗非鱼饲养100 d后,运用"加性-显性"遗传分析模型,分析了4组F1罗非鱼8个生长相关性状杂种优势、遗传效应以及与性状间的相关性。结果表明:(1)F1群体平均优势为0.129 4~0.368 4。除尾柄长超亲优势较大外,其他性状的群体超亲优势较小或表现出负向超亲优势。(2)8个性状的广义遗传率(HB)为0.714 2~0.995 3,表明加性效应和显性效应对性状的遗传变异影响极显著(P<0.01)。除尾柄长外,其他性状的狭义遗传率(HN)介于0.469 4~0.737 9,表明加性遗传方差在表型方差中所占比率较高。(3)体质量、全长、体长、体高、体宽、头长、尾柄长、尾柄高性状之间表型相关在0.776 6~0.999 7范围内,而遗传相关在0.994 1~1.000 0之间,表明这些性状间都存在极显著的正相关。取样结束后,采用3.95×106CFU/m L的海豚链球菌菌液进行腹腔感染,吉富罗非鱼自繁组F1代12 h后出现死亡,而奥利亚罗非鱼自繁组F1192 h后才出现死亡。384 h后,吉富罗非鱼自繁组F1死亡率为40%,正反交组F1分别为20%和23.3%,奥利亚罗非鱼自繁组F1死亡率最低,为6.67%。研究结果表明,除尾柄长外,杂交F1的其他性状不具备超亲优势,然而杂交可以提高选育后代的抗病力。
译 名：
Comparison of genetic traits and disease resistance of GIFT Oreochromis niloticus,O. aureus and their reciprocal hybrids F_1 offspring
作 者：
QIANG Jun;YANG Hong;MA Xinyu;WANG Hui;XU Pao;HE Jie;ZHU Zhixiang;LI Ruiwei;Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences;Wuxi Fisheries College,Nanjing Agricultural University;School of Life Science,Huaiyin Normal University;Maonan Sango Tilapia Breeding Base;
关键词：
GIFT Oreochromis niloticus;;Oreochromis aureus;;genetic traits;;heterosis;;Streptococcus iniae
摘 要：
Hybridization( interspecific hybrid) has been used in numerous species to increase grow th rate,manipulate sex ratios,produce sterile animals,improve flesh quality,increase disease resistance,improve environmental tolerance and improve a variety of other desirable traits to make aquaculture more profitable.GIFT( Genetically Improved Farmed Tilapia) strain Nile tilapia is the main kind of cultured tilapia,w hich has many advantages such as rapid grow th rate and high fillet yield. How ever,GIFT tilapia has poor disease resistance capability to Streptococcus iniae infection,w hich may be related to too much inbreeding. Breed improvement by interspecific hybrid may enhance disease resistance capability in tilapia. A complete diallel mating system betw een GIFT tilapia and O. aureus and additive-dominant genetic model w ere used to analyze heterosis of 8 grow th-related traits,genetic effect and correlation of traits. At the time of day 100 over the experiment,the results indicated that:( 1) Heterosis of grow th related traits in F1 hybrid varied from0. 129 4 to 0. 368 4,and population heterosis over parent mean( Hpm) of these growths related traits were all positive in F1. In addition to caudal peduncle length( CPL),other grow th related traits have negative or insignificant positive population heterosis over parent better( Hpb);( 2) The general heritability in the broad sense( HB) with 0. 714 2- 0. 995 3 indicated that genetic variations of all 8 traits were significantly influenced by additive effect and dominance effect( P < 0. 01),w hereas,the narrow sense of grow th-related traits except CPL varied from 0. 469 4 to 0. 737 9,and indicated additive effect controlled the genetic variation of output value;( 3) The phenotypic correlations 0. 776 6- 0. 999 7 and genetic correlations0. 994 1- 1. 000 0 betw een body w eight,body length,total length,body w idth,body height,head length,caudal peduncle length and caudal peduncle height,w ere all highly statistically significant( P < 0. 01).Furthermore,after sampling,experimental fish w ere infected w ith 3. 95 × 106 CFU / m L S. iniae through abdominal cavity. F1 generation of GIFT tilapia purebred combination died 12 h later,w hereas F1 generation of Aureus tilapia purebred combination died 192 h later. 384 h after infection,mortality of F1 for GIFT purebred combination w as 40%,w hile mortality of the reciprocal cross combinations w as 20% and 23. 3%respectively. The low est mortality( 6. 67%) w as found in F1 for Aureus purebred combination. Overall,the results indicate that,except CPL,other grow th related traits have no heterosis; how ever,hybridization can improve the disease resistance of breeding offspring.
