紫贻贝和厚壳贻贝杂交及F1代杂交优势初探

A primary study on hybridization of Mytilus galloprovincialis,Mytilus coruscus,heterosis of F_1 generation

2005-2007年对紫贻贝(Mytilus galloprovincialis)和厚壳贻贝(Mytilus coruscus)种间进行了杂交生产性试验,通过亲贝强化培育、确认雌雄亲贝、改革育苗水体交换方法、投喂混合单细胞藻类、流水培养附着稚贝等技术,获得F1代。结果表明,正交F1代幼虫的成活率明显高于反交F1代和厚壳贻贝,在幼虫培育前期与紫贻贝的成活率相当,但随着幼虫的发育有高于紫贻贝的趋势。正交F1代幼虫的壳长和壳高在培育阶段的前期生长与紫贻贝相当,低于厚壳贻贝,高于反交F1代;但后期的生长明显增快,并高于反交F1代和其他两种贻贝。各试验组贻贝海区养殖的成活率在90%以上,正交F1代最高,显著高于反交F1代。各试验组生长特性,正交F1代>紫贻贝>厚壳贻贝>反交F1代。其中正交F1代获附着稚贝3.77×109ind。正交F1除在孵化率上低于紫贻贝、厚壳贻贝外,在壳长、壳高、成活率等方面指标具有一定杂交优势,而反交F1代的杂交优势不明显。

Studies on hybridization between Mytilus galloprovincialis and Mytilus coruscus and pilotscale breeding were carried out from 2005 to 2007. F1 were obtained with technologies of intensive culture of parental mussel, identification of male and female, amelioration of waterbodies exchange of breeding, feeding compound tiny algae, etc. The results showed that the average shell length and the average shell height of positive cross F1 juvenile which were cultivated in the sea was 1.13 mm and 0.78 mm, respectively, those of negative cross F1 juvenile being 0. 751 mm and 0. 485 ram, those of M. coruscus juvenile being 0. 694 mm and 0. 517 mm, those of M. galloprovincialis juvenile being 1.10 mm and 0.75 ram. The surviving ratio of positive cross F1 was higher than that of negative cross F1 and M. coruscus in larvae stage. The surviving ratio of positive cross F1 was equal to that of M. galloprovincialis in the prophase of the larvae stage. In the anaphase of the larvae stage the surviving ratio of positive cross F1 was higher than that of M. galloprovincialis. In the prophase of the larvae stage the growth of positive cross F1 was equal to that of M. galloprovincialis, being slower than that of M. coruscus, being quicker than negative cross F1. In the anaphase of larvae stage the growth of positive cross F1 was most speedy. The surviving ratio of adult mussel was over ninety percent and the surviving ratio of positive cross F1 was highest in the four experimental groups. The growth characters are positive cross F1 〉M. galloprovincialis 〉M. coruscus 〉 negative cross F1. 377 million juvenile mussels of positive cross F1 were obtained. Advantages of positive cross F1 exist in shell length, shell height, and survival ratio, compared with M. galloprovincialis and M. coruscus. But the hatching rate is lower. No obvious advantages were found in negative cross F1.