为揭示菊花的自交衰退现象,对菊花品种 ‘rm1-3’(Dendranthema morifolium ‘rm1-3’)和 ‘02-42-6’(D.morifolium’02-42-6’)亲本及其自交后代(I1代、I2代和I3代)的生长性状及部分表型性状进行了比较分析。结果表明,品种 ‘rm1-3’I1代和I2代的单花结实数分别比亲本减少89.5%和97.2%,品种’02-42-6’I1代和I2代的单花结实数分别比亲本减少91.2%和92.0%,差异极显著(P<0.01)。2个品种自交后代的平均出苗率呈现随自交世代的增加逐渐降低的趋势,其中品种’rm1-3’自交后代各世代间的平均出苗率均有极显著差异(P<0.01);品种 ‘02-42-6’的I3代平均出苗率极显著低于I1代和I2代(P<0.01)。2个品种亲本与其自交后代间叶片长度没有显著差异,但亲本的存活率、株高、开花率和花径均显著高于自交后代,且在自交后代中,I1代的存活率、株高、开花率和花径均高于I2代和I3代。2个品种自交后代的冠幅和单株花数也低于各自的亲本,但I1代的冠幅和单株花数与亲本无显著差异。品种 ‘rm1-3’的I1代、I2代、I3代和品种 ‘02-42-6’的I1代、I2代的开花时间较亲本分别推迟了9.4、8.9、5.9、11.9和7.6d,且随自交世代的增加逐渐缩短;但品种 ‘02-42-6’的I3代开花时间却较亲本提前了10.7d。研究结果说明菊花自交后代存在严重的衰退现象。

To reveal inbreeding depression, the growth characters and some phenotypic traits of parents and self-crossed progenies (I1,I2andI3) of Dendranthema morifolium `rm 1-3' and D. morifolium `02-42-6' were comparatively analyzed. The results show that compared with each parents, number of seed setting per flower of I1 and I2 progenies of `rm 1-3' reduces 89.5% and 97.2%, that of I1 and I2 progenies of `02-42-6 ' reduces 91.2% and 92.0%, respectively, the differences are highly significant (P< 0.01). The average germination rate of self-crossed progenies of two cultivars gradually decreases with self-crossed generation increasing, in which that among progenies of `rm 1-3' has highly significant difference and that of I3 progeny of `02-42-6' is very significantly lower than that of I1 and I2 progenies(P< 0.01). There is no significant difference of leaf length between self-crossed progenies and their parents of two cultivars, but survival rate, plant height, flowering rate and flower diameter of parents are significantly higher than those of self-crossed progenies. Survival rate, plant height, flowering rate and flower diameter of I1 progenies of two cultivars are higher than those of I2 and I3 progenies. The crown width and flower number per plant of self-crossed progenies of two cultivars are also lower than those of their parents, but those of I1 progenies have no significant differences with those of their parents. In addition, compared with their parents, the flowering time of I1, I2, I3 progenies of `rm 1-3' and of I1, I2 progenies of ` 02-42-6' postpones 9.4, 8.9, 5.9, 11.9 and 7.6 d, respectively, and the postponed days shorten gradually with self-crossed generation increasing, but that of I3 progeny of ` 02-42-6'  is ahead 10.7d than its parent. It is suggested that the self-crossed progenies of Dendranthema morifolium have obvious in breeding depression compared with their parents.