不同近交系数蛤仔橙色品系的生长和成活研究

以不同遗传背景的蛤仔（Ruditapes philippinarum）橙色品系为材料,采用建立半同胞家系子一代H1（F=0.125）、全同胞家系子一代F1（F=0.250）、全同胞家系子四代F4（F=0.594）及自然对照组C1（F=0）的方法,进行了不同近交系数蛤仔橙色品系生长和成活的研究.结果表明,在整个养殖周期中F1组的壳长生长最慢,在稚贝期和养成期均显著小于F4和C1组（P＜0.05）,H1、F4和C1组之间的壳长生长差异不显著（P＞0.05）.C1组的成活率在整个养殖周期中为最小,除幼虫期3日龄外,其他各日龄均显著小于其他试验组（P＜0.05）,而H1、F1和F4组之间的成活率则差异不显著（P＞0.05）.试验组F1壳长生长的衰退率为2.92％ ～ 18.33％,平均值为（12.05±6.54）％,试验组H1在稚贝期、养成期显现出一定的衰退现象,而试验组F4在整个养殖周期中均未表现出近交衰退现象;各试验组的成活性状在各日龄均未出现近交衰退.该研究为橙色品系的选育奠定一定的理论基础.     

虾夷扇贝獐子岛红品系家系建立及生长发育的比较

采用不平衡巢式设计(♂∶♀=1∶3),建立了12个金贝广场挑选的獐子岛红虾夷扇贝父系半同胞(A、B、C……L)和36个母系全同胞(A1、A2、A3,B1、B2、B3,C1、C2、C3……L1、L2、L3)家系,比较各家系间浮游幼虫期和稚贝期的生长及存活指标,以评估虾夷扇贝"獐子岛红"品系的生长性状。结果表明,K3家系5日龄幼虫生长速度最快,比生长最慢的B3平均壳长大9.40%;I1家系在15日龄时生长速度最快,壳长为164.83μm,C3、D3家系25日龄壳长最大,较平均壳长高17.71%;D2家系120日龄稚贝壳高生长最快,较生长最慢的C1和D1家系平均壳高大40.41%;D2家系180日龄壳高依然最高,较H1平均壳高(18.3mm)高38.96%。I1家系幼虫存活率最高,较D1家系平均存活率高17.67%;F2家系稚贝存活率最高,显著高于其他试验组(P0.05,n=108)。综合36个同胞家系的各指标,D2、I1家系生长、抗逆性状最优,可作为优良品种选育的育种材料。     

菲律宾蛤仔家系的建立及早期生长发育

采用不平衡巢式设计建立33个菲律宾蛤仔家系(11个父系半同胞家系和33个全同胞家系),并对各家系蛤仔的卵径、受精率、孵化率及生长、存活和变态的相关指标进行了分析。结果表明:各家系蛤仔的卵径、受精率无显著差异(P>0.05,n=90),但孵化率有明显差异(P<0.05,n=90)。在不同时期各家系蛤仔的生长情况不同。幼虫期间,9日龄C2生长最快比生长最慢的F2平均壳长大28.24%,且差异显著(P<0.05,n=90)。D3绝对生长最大比平均值高37.24%。稚贝期间,40日龄I1生长最快比生长最慢的B3平均壳长大78.29%,且差异显著(P<0.05,n=90)。I1绝对生长也最大比平均值高87.61%,其中400～500μm个体占30%,500μm以上个体占53.33%,家系内个体趋于大型化,而B1、B3家系内个体生长性状出现衰退现象,趋于小型化,300μm以下个体分别占整个家系的83.33%、90%。在相同时期各家系蛤仔的存活率不同。幼虫期间,9日龄I2存活率最高比平均存活率高94.14%,E3存活率最低比平均存活率低72.65%。稚贝期间,40日龄时各家系稚贝的存活率较高,都在85%以上。变态期间,同胞...     

壳金长牡蛎家系的建立及生长和存活性状的比较

于2014年6月,以经过2代家系选育和2代群体选育共连续4代选育的壳金长牡蛎为亲本,采用巢式设计,成功构建25个全同胞家系,同时以未经选育的壳色即普通灰白色的个体子代为对照组,评估各家系和对照组在幼虫、稚贝期的生长和存活差异。结果显示,不同时期,壳金长牡蛎选育家系各生长性状平均值均高于对照组平均值,其中在幼虫期不同日龄,壳金长牡蛎所有家系壳高和存活率平均值均高于对照组,分别提高2.27%~16.67%和1.72%~9.40%;在稚贝期各阶段,壳金长牡蛎所有家系壳高、壳长、总重量及存活率的平均值均高于对照组,分别提高10.04%~19.79%、6.56%~17.78%、10.44%~32.92%和0.20%~4.26%;不同壳金家系间的生长及存活性状具有显著差异,排序也存在不一致性,其中G19和G28家系表现出较高的生长及存活性能,在11月龄,G19和G28家系的壳高、壳长、总重的累积生长量比所有家系平均值分别提高4.78%、8.22%、12.38%和7.61%、4.02%、9.04%,与对照组相比,分别提高15.31%、15.31%、24.11%和18.42%、10.85%、20.42%;存活率比所有家系平均值和对照组分别提高11.70%、12.71%和11.92%、12.94%。研究表明,壳金长牡蛎选育群体的生长性状具有一定的优势,但存活性状有待进一步的改良;家系G19和G28可作为优良品种培育的育种材料。本研究为培育快速生长和存活率高的壳金长牡蛎新品种提供了基础资料。     

魁蚶(Scapharca broughtonii)中国群体与韩国群体杂交子一代的生长和存活比较

以魁蚶(Scapharca broughtonii)中国群体(C)和韩国群体(K)为材料,进行了4个组合的杂交和自交实验,分析了各实验组的受精率、孵化率、幼虫和稚贝的生长、存活以及杂交子一代的杂种优势。结果显示,4个组的受精率和孵化率均较高(80%以上);自交组的受精率略高于杂交组,但孵化率无显著差异。在幼虫期,KK组和KC组的壳长平均值大于CK组和CC组,但存活率和变态率无显著差异;在稚贝期,KK组和KC组的壳长平均值也均大于CK组和CC组,但CC组和CK组的保苗率比KC组和KK组高。综合分析比较表明,杂交KC组的杂种优势率在幼虫期和稚贝期的壳长生长上均表现为正值,在稚贝期的存活率方面也表现为正值,杂交KC组结合了两群体的部分优良性状,是理想的育种材料。     

壳紫长牡蛎家系生长存活比较及生长性状的遗传参数评估

为了培育壳色和生长性状优良的壳紫长牡蛎(Crassostreagigas)新品系,2021年通过家系选育的方式,以壳色性状为主要选育指标,建立了第1代壳紫长牡蛎选育群体。本研究以壳紫F1为亲本,采用平衡巢式设计建立了36个全同胞家系,并以野生长牡蛎为亲本建立对照组,比较分析了各家系在生长和存活方面的性能表现;同时利用多性状动物模型对壳紫家系幼虫和稚贝期的生长性状遗传参数进行了评估。结果显示,不同生长阶段壳紫长牡蛎家系的存活率和壳高均值均高于对照组,幼虫期分别提高了1.49%～10.18%和3.75%～15.94%,稚贝期分别提高了4.05%～16.94%和15.95%～18.25%。不同壳紫家系的生长和存活情况也存在差异,没有发现在存活率和生长性状方面同时具有优势的家系。壳紫长牡蛎幼虫期壳高和壳长的狭义遗传力范围分别为0.43～0.84和0.49～0.80,稚贝期壳高和壳长的遗传力分别为0.15～0.33和0.18～0.37,均属于中高等遗传力。不同生长阶段壳紫长牡蛎家系壳高和壳长的遗传相关与表型相关均为正相关,幼虫期的相关系数分别为0.67～0.97和0.17～0.51,稚贝期为0....     

菲律宾蛤仔福建与广东群体的双列杂交

2015年9月–12月,以菲律宾蛤仔福建养殖群体和广东野生群体子一代为亲本,开展了双列杂交实验,建立了两个自交组和两个杂交组,研究了杂交子代幼虫和稚贝的生长与存活的杂种优势。结果显示,各实验组均有较高的受精率和孵化率,但无显著差异。总体上,幼虫期的生长受母体效应影响显著,稚贝期的生长杂交效应主要受交配方式影响。相反,幼虫期的存活受配对方式影响最显著,稚贝期的存活受卵源影响显著。在幼虫期,杂交组与自交组在生长和存活方面差异不显著。在稚贝期,生长表现出明显的杂种优势,壳长和壳高在30日龄以后,正反交组的平均生长速率显著快于自交组。在40日龄时,壳高和壳长总杂交优势值达到最大,分别为25.64和27.00。这可能是因为杂种优势的表达具有时期差异性。在幼虫期,福建自交组表现出最高的存活率,为36.45%±1.85%;稚贝期,广东自交组存活率最高,为52.27%±2.13%。在幼虫期和稚贝期的存活率方面,未观测到杂种优势,这可能是由于两个杂交亲本群体与存活相关的基因频率无差异或者检测次数较少所致。     

壳金长牡蛎自交和杂交家系生长与存活比较

选择具有生长优势的长牡蛎(Crassostrea gigas)G2(A)家系及具有明显生长和存活优势的G19(B)和G28(C)家系进行完全双列杂交,得到包括3个自交组(AA、BB、CC)和6个杂交组(AB、AC、BA、BC、CA、CB)共9个壳金长牡蛎实验组,分析各实验组在幼虫期及稚贝期不同日龄的各生长指标和存活性能,并评估了杂交组的杂种优势。结果表明,在整个培育阶段,大多数杂交组在不同生长时期均表现出较高的生长和存活性能,其中,浮游幼虫期5日龄,所有杂交组的壳高和壳长均显著大于自交组(P0.05);10日龄后,杂交组CB、BC和AC的壳高显著大于相应的自交组(P0.05),杂种优势明显;稚贝期85和130日龄,杂交组CB的壳高性能大于其他实验组。浮游幼虫期10日龄,CB组存活率显著大于AA、CA组(P0.05);稚贝期85日龄后,杂交组AC、CA和CB的存活率杂种优势逐渐增大;190日龄,杂交组AC、BC与自交组AA、CC之间存活率差异显著(P0.05)。研究结果为壳金长牡蛎新品种的培育及杂种优势的充分利用奠定了重要基础。     

不同壳色虾夷扇贝家系F1幼虫生长及遗传结构的比较分析

虾夷扇贝(Patinopecten yessoensis)群体存在2种壳色个体,简称白贝和褐贝。本研究通过近交和杂交方法建立了褐贝(♀)×褐贝(♂)、白贝(♀)×褐贝(♂)、褐贝(♀)×白贝(♂)和白贝(♀)×白贝(♂)4个家系,分别用1F、2F、3F和4F代表,每家系设3个平行,共12个家系。对各家系的卵径、幼虫的孵化率、成活率和生长性状等生物学参数进行了比较,建立了各个家系幼虫壳长、壳高的生长方程,并利用微卫星标记比较4个家系的遗传差异。结果表明,不同壳色家系间卵径大小、幼虫的孵化率、成活率差异不显著(P0.05),家系4F幼虫期壳长和壳高日生长速率均高于1F、2F和3F,且差异显著(P0.05),家系2F、3F和4F间幼虫期壳长和壳高日增长速率差异不显著(P0.05)。家系1F的遗传多样性最低;遗传相似性系数(0.6351～0.9772)和遗传距离(0.0231～0.4540)分析表明,1F和4F之间遗传相似性(0.6351)最低,遗传距离(0.4540)最远;不同家系间存在着遗传差异,1F和4F差异最大。本研究结果初步说明虾夷扇贝群体内白贝个体和褐贝个体之间产生了遗传分化,这种遗传结构的差异造成了不同壳色家系在幼虫阶段生长性状上的不同。     

香港巨牡蛎与近江牡蛎杂交及回交子代早期生长发育比较

为评估香港巨牡蛎与近江牡蛎杂交及回交育种的可行性,本文以香港巨牡蛎(Crassostrea hongkongensis)与近江牡蛎(Crassostrea ariakensis)为材料,比较了两种牡蛎杂交与回交子代的受精率、孵化率、幼虫及稚贝的生长和存活率。结果表明：香港巨牡蛎卵子可以与近江牡蛎精子受精,受精率为47.33±2.52%,但近江牡蛎卵子与香港巨牡蛎精子不受精。在回交实验中,香港巨牡蛎(H♀)与近江牡蛎(A♂)的杂交牡蛎 (HA)与香港巨牡蛎(HH)或近江牡蛎(AA)都可以正常交配,但各回交组受精率明显低于两牡蛎自交组(P＜0.05)。受精后,HA与AA回交组的孵化率最低,分别为20.33±2.08%(♀A×♂HA),55.67±2.52%(♀HA×♂A),其它各实验组孵化率均大于70%。幼虫期, HA幼虫存活率明显低于两牡蛎自交组HH和AA(P＜0.05);HA幼虫生长快于AA, 但慢于HH;♀A×♂HA回交组和HA自繁组的幼虫存活率为0。稚贝期,HA稚贝存活率与HH、AA自交组存活率差异不显著(P>0.05)。HA稚贝生长快于HH, 但慢于AA。另外,研究发现♀H×♂HA回交组幼虫和稚贝的生长与HA差异不显著(P>0.05),优于其它回交组;♀H×♂HA回交组幼虫的存活率与HA差异不显著(P>0.05),其稚贝的存活率虽低于HA,但优于其它回交组。本研究为牡蛎种间杂交及回交育种奠定了一定的理论基础。     

凡纳滨对虾选育群体与近交群体、引进群体生长和存活性能比较

为研究凡纳滨对虾选育群体与近交群体、引进群体的生长和存活性能差异,本实验利用家系标准化构建方法构建了选育群体、引进群体和近交群体家系,开展共同养殖环境下的生长和存活性能测试实验,分析了三个群体的体质量、存活率和近交衰退情况.结果表明,选育群体收获体质量与引进群体、全同胞近交一代群体体质量均存在显著差异(P＜0.05),第60天收获时,选育群体比引进群体的体质量提高7.11％,比近交群体的体质量提高20.01％;选育群体和引进群体内不同家系生长速度存在较大差异,选育群体中增重最快的家系为6012家系,绝对增重率为0.29 g/d,比所有家系绝对增重率均值高31.82％,比增重最慢的家系高61.11％,引进群体中绝对增重率和特定生长率均最高的家系为6008家系,分别为0.33 g/d和3.17％/d,比所有家系均值分别高65％和33.19％,比增重最慢的家系分别高230％和128.06％;存活率方面,选育群体与引进群体差异不显著(P＞0.05),但与近交群体存在显著性差异(P＜0.05),存活率提高12.74％.近交衰退结果显示,与选育群体及引进群体相比较,近交群体收获体质量生长性状的实际衰退百分比分别为16.68％和10.76％,近交系数每增加10％所引起的近交衰退系数分别为-6.60％和-4.30％,且选育群体与近交群体在收获体质量上差异显著(P＜0.05);存活率性状也出现了一定程度的近交衰退,实际衰退百分比分别为11.30％和10.54％.本研究结果可为凡纳滨对虾的后期选择育种工作提供数据参考.     

Inbreeding Effects on Hatchery and Growout Performance of Pacific White Shrimp, Penaeus (Litopenaeus) vannamei

In animal breeding programs, selection coupled with a narrow genetic base can cause high levels of inbreeding to occur rapidly (in one or two generations). Although the effects of inbreeding have been studied extensively in terrestrial animals and to a lesser extent in aquaculture species, little is known about the effects of inbreeding on penaeid shrimp. The objective of this study was to investigate the effects of inbreeding on hatchery and growout performance of the Pacific white shrimp, Penaeus vannamei. The experiment was conducted over 2 yr, and data from two successive generations (G₂ and G₃) of inbred (sibling–sibling mating) and outbred families were analyzed. There were 11 inbred and 12 outbred families in G₂ and 9 inbred and 10 outbred families in G₃. Inbreeding coefficients (F) for outbred and inbred families were 0.00 and 0.25, respectively, for G₂ and 0.00 and 0.375, respectively, for G₃. Growth rates for outbreds and inbreds were similar in both G₂ and G₃. Hatch rate for inbred families was 33.1% lower than for outbred families in G₂ and 47.1% lower in G₃. Inbreeding depression (IBD) (relative change in phenotype per 0.1 increase in F) ± 95% CI for hatch rate was ?12.3 ± 10.1%. Hatchery survival for inbred families was 31.4% lower than for outbred families in G₂ and 38.8% lower in G₃. IBD for hatchery survival was ?11.0 ± 5.7%. Growout survival was 1.9% lower for inbred families than for outbred families in G₂ and 19.6% lower in G₃. IBD for growout survival was ?3.8 ± 2.9%. There was also a significant linear relationship between IBD estimates for survival traits and mean outbred survival. At high outbred survival, IBD was low (e.g., growout survival in G₂), but IBD appeared to become more severe when outbred survival was lower. This suggests that stress (related to environment and/or life stage) may worsen IBD for survival traits. Results also indicate that moderate to high levels of inbreeding (>10%) should be avoided in commercial shrimp hatcheries because the cumulative effect of IBD on hatch rate and hatchery survival will significantly reduce postlarvae production. Thus, IBD can be significant enough to justify the use of inbreeding as a germplasm protection strategy (under certain scenarios) for genetic improvement programs.     

Inbreeding evaluation using microsatellite and its effect on growth traits in turbot,Scophthalmus maximus

Turbot is an economically relevant fish, and simultaneously at the risk of inbreeding depression in China. Microsatellite DNA markers were used to evaluate inbreeding level of a random turbot breeding population and further investigate its effects on growth traits. DNA based inbreeding coefficients (F_DNA) were ranged from 0 to 0.4124. Average inbreeding coefficient was 0.0621 with a standard deviation of 0.0658. Regression analysis results showed inbreeding had a very significant (p < .01) effect on harvest body weight (BW) and significant (p < .05) effect on harvest body long (BL). Inbreeding depression, expressed as the percent change in phenotype per 10% increase in F, was ?4.00% for BW and ?1.14% for BL. The inbreeding depression on high inbreeding coefficient (more than 10%) individuals was further analyzed. A set of significant (p < .05) and larger inbreeding depression was obtained, ?7.15% and ?2.49% for BW and BL respectively. This study demonstrates that inbreeding has a negative effect on growth traits and highlights the need of DNA markers to control inbreeding and maximize the genetic diversity in selection breeding programs.     

近交及其对水产养殖的影响

因大多数野生物种的捕捞已接近甚至超过了可开发的限度，因此必须大量增加水产品的养殖以满足人们对水产品的需要。目前，许多水产养殖种类的苗种来源于野生亲体或野生种苗，但是当野生种群被过度捕捞或数量大量减少时，越来越多的苗种将来源于人工蓄养的亲体群体。     

Heterosis analysis at early generations for complete diallel crosses in three different geographical culture populations of Sinonovacula constricta (Lamarck 1818) in Zhejiang,China

The paper reports a study focused on breeding new rapidly growing and heat‐tolerant strains in a commercially important Asian bivalve, Sinonovacula constricta. To breed a new strain of S. constricta with fast growth and high temperature tolerance, complete diallel crosses were carried out using three different geographical culture populations from Zhejiang (Z), Fujian (F) and Guangdong (G) provinces, China. Larval and spat growth and the survival and heat tolerance of spats were compared in detail. The experimental serial growth traits extracted from larval and spat measurements (shell length and shell height) indicated that there was no difference between six hybrid crosses and parental crosses at the larval stage; while at the spat stage, some differences were observed. The hybrid crosses ZF (Z♀ × F♂), ZG (Z♀ × G♂) and FG (F♀ × G♂) outperformed the parental groups in shell length at the end of intermediate culture, with lengths of 21.77 ± 0.28 mm, 21.55 ± 0.29 mm and 21.44 ± 0.20 mm respectively. For spat survival rate, the hybrid cross ZF (Z♀ × F♂) had a significantly larger value (88.89 ± 4.16%) than all the other groups, and the hybrid cross ZG (Z♀ × G♂) had a significantly larger rate than the cross GZ (G♀ × Z♂) and parental crosses ZZ (Z♀ × Z♂) and GG (G♀ × G♂). The hybrid crosses ZF (Z♀ × F♂), ZG (Z♀ × G♂) and FG (F♀ × G♂) exceeded the parental groups in heat tolerance, but there was no significant difference. The growth, survival and heat tolerance results showed that the crosses ZF, ZG and FG in this study were the best hybridization combinations for genetic improvement, which could have significant implications for the development of razor clam aquaculture. This work provides a theoretical basis for breeding new varieties (strains) that grow rapidly and are heat tolerant.     

Inbreeding depression traits in pacific abalone Haliotis discus hannai by factorial mating experiments

ABSTRACT:   'Inbreeding depression' may be an avoidable phenomenon for abalone culture. However, only a few studies have been carried out on inbreeding depression. In the present study, using six families produced in 1994, a factorial mating system including inbreeding and outbreeding was constructed in order to demonstrate inbreeding depression traits of the Pacific abalone. In total, 24 inbreeding and 21 outbreeding crosses were produced during three years (1999–2001) and these offspring were reared for approximately one year. Significant differences in fertilization rate and growth were not observed between inbreeding and outbreeding crosses. However, the deformity rate of veliger larvae was always higher in inbreeding crosses than that of outbreeding crosses in all experiments. Moreover, a significantly high deformity rate was observed in some full-sib families of inbreeding. Alternatively, the survival rates of inbreeding crosses were much lower than for outbreeding crosses after about 4 months and one year in two rearing localities. These results indicate that inbreeding depression is observed in the traits of deformity rate and survival, but not in fertilization rate nor growth in the first generation of a full-sib family of the Pacific abalone.