青蛤壳色遗传初步研究

本实验对自然种群青蛤的壳色进行了观察和分析;将亲贝分为白壳群体和紫壳群体分别进行人工繁育,对F1壳色分离情况进行了统计和分析;分析了泥质、粉沙质和细沙质不同底质对F1壳色表达的影响。结果表明:(1)F1出现了4种壳色类型,两群体间相同壳色个体百分率差异均显著(P﹤0.01),F1壳色出现相同于亲本的纯化,说明青蛤白、紫壳色能够真实遗传;(2)青蛤紫色壳色的深浅明显受到底质的影响,泥质使壳色变淡并降低了紫壳个体百分率,沙质底则利于紫色壳色的表达,其中细沙质与泥质差异达到显著性水平(P﹤0.05),但底质影响力不超过遗传能力的1/4;(3)紫壳群体F1的紫壳个体百分率达70%以上,接近未分离亲贝18.71%的4倍,使紫壳个体得到显著纯化,为选育纯紫壳品系或群系创造了条件。

Preliminary study on shell color inheritance of Cyclina sinensis

The shell color characters of natural population Cyclina sinensis (Gmelin) were observed and analyzed. The natural group was divided into white and purple shell groups for artificial breeding respectively. The F₁ shell color segregation was counted and analyzed. The influence of different sediments on F₁ shell color expression was analyzed by experiment with mud, silt and fine sand. Results showed that, (1) F₁ displayed 4 shell color types, the percentage difference of same shell color individuals between the two groups was significant (P<0.01), the F₁ shell color purified the color of parents, which indicated white and purple shell color are truly hereditary; (2) the purple shell color depth was obviously influenced by sediment, and muddy sediment made the purple shell color light and lowered the individual percentage; sandy sediment was conducive to the purple shell color expression, and percentage difference between fine sandy and muddy reached significant level (P<0.05), but the sediment influence did not exceed 1/4 of the genetic capacity; (3) the purple shell percentage of purple group F₁ was more than 70%, nearly 4 times of not separated parents(18.71%), so that purple shell individuals have been significantly purified. This creates good conditions for breeding pure purple shell strain or polygenetic strain.