罗氏沼虾多次产卵对子代生长与遗传结构的影响研究

Study on effects of multiple spawning on growth and genetic structure of progeny of Macrobrachium rosenbergii

为了提高罗氏沼虾苗种品质,采用单因素完全随机设计方法对同一雌虾5个产卵批次子代(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ)的生长性能进行比较分析。结果表明:幼体数量随产卵次数增加而增加,前三产卵批次具有较高出苗率。各产卵批次子代绝对增重率大小顺序为Ⅲ>Ⅱ>Ⅴ>Ⅳ>Ⅰ,经LSD法多重比较,Ⅱ和Ⅲ批次子代表现出明显的生长优势,Ⅰ批次子代成活率显著高于后四批次(P<0.05),前三批次子代体重变异系数小于后两批次,表明前三批次养成规格更加整齐。Ⅰ、Ⅱ、Ⅳ和Ⅴ批次子代在养殖60 d后雌性比例较高,而Ⅲ批次子代雌雄比符合1∶1。利用微卫星分子标记分析5个产卵批次子代的遗传多样性及遗传距离,结果显示:5个产卵批次子代的多态信息含量(PIC)大小顺序为Ⅱ(0.586 3)>Ⅰ(0.583 5)>Ⅴ(0.560 2)>Ⅲ(0.560 1)>Ⅳ(0.555 8),均为高度多态。Ⅰ批次子代与Ⅴ批次子代间遗传距离最大为0.017 0,Ⅳ批次子代与Ⅴ批次子代间遗传距离最小为0.000 3,各批次子代间遗传关系极近,表明5个产卵批次子代的遗传结构无明显差异。

In order to improve the quality of larvae of Macrobrachium rosenbergii,growth performance of progeny of 5 spawning batches（ Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ） were checked by one-way completely randomized design.The results indicated that,the number of larvae increased with spawning number increasing,and the first three spawning batches had higher survival rate. The ranks of AGR were Ⅲ Ⅱ Ⅴ Ⅳ Ⅰ,Ⅱ,Ⅲspawning batches showed obvious growth advantage after AGR comparison by LSD. Survival rate of Ⅰbatch was significantly higher than other four batches. Variation coefficient of body weight of first three spawning batches was lower than last two. It showed the figure of first three spawning batches were more tidy. The quantity of female shrimp atⅠ,Ⅱ,Ⅳ,Ⅴ batch is greater than males after 60 days feeding,but the sex ratio（ ♀/♂） of Ⅲ meets 1 ∶ 1. Microsatellite markers were used to analyze the genetic diversity and genetic differentiation of 5 spawning batches. The results showed that： polymorphism information content（ PIC） of 5spawning batches in order was Ⅱ（ 0. 586 3） Ⅰ（ 0. 583 5） Ⅴ（ 0. 560 2） Ⅲ（ 0. 560 1） Ⅳ（ 0. 555 8）.These all were highly polymorphic. The longest genetic distance（ 0. 017 0） was between Ⅰ batch and Ⅴbatch,the shortest genetic distance（ 0. 000 3） was between Ⅳ batch and Ⅴbatch. The genetic relationships among each offspring batch were very close. It indicated that there were no significant differences of genetic structure among 5 spawning batches.