合浦珠母贝三倍体和二倍体的生长比较

COMPARISON OF GROWTH BETWEEN TRIPLOID AND DIPLOID OF Pinctada martensii (D.)

合浦珠母贝Pinctada martensii(D.)三倍体和二倍体的生长测定表明,三倍体成贝平均壳高、壳长、壳宽和体重均超过二倍体同胞,差异极显著(P<0.01)。特别是抑制第一极体形成的三倍体,经两年养殖,壳高、体重和肉重分别比二倍体增加13.01％,44.03％和58.37％。在繁殖期,三倍体的增长率显著超过二倍体。非繁殖期的大多数月份,三倍体的增长率和二倍体相差不大。因此,可以认为三倍体生长速度快主要是由于三倍体的生殖腺发育受阻,体内积累的能量转移到体细胞生长所致。

The growth measurement on triploid and diploid of Pinctada mar-tensii (D.) showed that mean shell height, shell length, shell width and body weight of triploid adults were all greater than those of their diploid siblings, and the differences were highly significant (p<0.01 ). Especially after two year's culture, shell height, body weight and soft part weight in triploid induced by blocking the first polar body formation were 13.01%, 44.03% and 58.37% greater than those of diploid respectively. During the reproductive period, the daily growth rate of triploid was obviously greater than diploid's. In most months of the unreproduc-tive period there was no significant difference in daily growth rate between triploid and diploid. It is suggested that fast growth of triploid might be due to retarded goiiad development and transformed storage energy in body into somatic growth. There is no direct relationship between ploidy and growth rate. It is worth to thoroughly investigate whether extra fast growth in triploid of the first polar body is related to their level of heterozygosity.