甜菜多胚四倍体品系制糖工艺品质性状的遗传潜势与选择

Inheritance and Selection for Beet Quality Characters in Multigerm Sugarbeet Tetraploid Breeding Lines

以12份多胚四倍体甜菜品系的随机区组试验结果,对制糖工艺品质性状及农艺性状进行了遗传潜势与选择研究。结果表明:除K含量外,品质性状品系间存在显著差异,含糖率、清汁纯度的遗传进度较小;Na含量、可回收糖量的遗传力、遗传变异系数和遗传进度均较大;对上述性状应在早代选择,但对于含糖率、清汁纯度等遗传变异小的性状,应扩大选择群体的变异范围,才能达到较好的选择效果。含糖率、清汁纯度、可回收糖量相互间呈极显著正相关,与杂质指数、Na含量、有害氮(α-N)含量、褐斑病(级)、生长势呈强或弱的负相关;Na、α-N含量、杂质指数等相互间呈强或弱的正相关。对可回收糖量正向选择和对杂质指数负向选择时,含糖率和清汁纯度的遗传进度较大。进一步对品质育种策略作了讨论。

Variance and covariance analysis was used to analyse quality characters in sugarbeet tetraploid lines. Twelve lines were used to evaluate growth vigour, Cercospora leaf spot susceptibility, root yield, sucrose content, K, Na, α-N and to calculate impurity index, clear juice purity, recoverable sugar yield and parameters of inheritance and predicted selection gain. There were significant genetic variations for sucrose content, Na, α-N content, purity, and recoverable sugar yield among breeding lines. Selection in early generation in a large population is advised as these traits also have high heritability. The correlations between sucrose content, purity and recoverable sugar yield are positive significantly. The correlations of these characters to impurity index, Na, α-N content, Cercospora disease and growth vigour grades were negative. Genetic gain for sucrose content, purity and sugar yield were obvious when positive selection for sugar yield and negative selection on impurity index. The enhancement of quality traits via selection, recurrent selection, heterosis utilization and gene-based molecular breeding was discussed in details.