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

Growth and Survival of the First Hybrid Generation of Chinese and Korean Populations of Scapharca broughtonii

中文关键词: 魁蚶  杂交  生长  存活  杂种优势

英文关键词: Scapharca broughtonii  Hybridization  Growth  Survival  Heterosis

中文摘要:

      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。

英文摘要:

      Intraspecific hybridization was investigated using two stocks of the Scapharca broughtonii, China population (C) and Korea population (K). The fertilization rate, larval survival rate, growth, and heterosis were compared between two reciprocal hybrid crosses C♀ × K♂ (CK) and K♀ × C♂ (KC) and two parental groups C♀ × C♂ (CC) and K♀ × K♂ (KK). The fertilization rate of the parental groups was higher than that of the reciprocal hybrid crosses, but the hatchability results indicated that there was no significant difference between the two reciprocal hybrid crosses and the two parental groups. The shell lengths of the KK and KC groups were larger than those of the CC and CK groups in larval, juvenile, and adult stages. The CC and CK groups, however, showed higher survival rate in juvenile and adult stages. The heterosis of the KC cross in terms of the shell length and the survival rate was obvious, but the CK cross did not show positive heterosis in any aspect during the entire experiment. The difference in heterosis between the two reciprocal hybrid crosses might be related to the maternal effects, heredity, and environment.