Abstract:

F₁ segregating populations were obtained from the crossing progenies between Micanthus sacchariflorus and M. floridulus, two Miscanthus species that had significant differences in several main agronomic traits. Using a mixed major gene plus polygene inheritance model,the traits including Number of nod (Non), Length of leaf (Lol), Width of leaf (Wol), Length of main stem length (Lms), Length of flower stalk (Lfs), Length of inflorescence (Loi), Plant height (Ph), Stem diameter(Sd), Number of tillers (Not), Weight of single tiller (Wst), Weight of the biggest single tiller (Wbt), and Weight of plant (Wop) in F₁ segregating populations were tested. The results showed that all these 12 agronomic traits presented a continuous single-peaked and skewed normal distribution, indicating that these traits were quantitative. The heterosis and extra-parent segregation existed in the F1 population. The heterosis value of mid-parent (Hm) for Non, Lms, Ph, Not and Wop was up to 35.79%, 64.62%, 30.65%, 584.12% and 160.99%, respectively. The mixed genetic analysis suggested that Lms, Wol, Loi and Wst were controlled by 2 major genes plus multiple minor genes, and Non, Ph and Wbt controlled by 1 major gene, while the other 5 traits controlled only by multiple minor genes. The Wop had a very significantly positive correlation with Wol, Not, Wst or Wbt, and a significantly positive correlation with Lof or Lms (P<0.05).In order to obtain hybrid progenies between M. sacchariflorus and M. floridulus with high biomass yield, the selection concerning the number of tillers should be emphasized.

Key words: Miscanthus sacchariflorus, M. floridulus, Major gene plus polygene, Genetic analysis, Correlation analysis

摘要：

为了探讨芒属植物种间杂交种后代主要农艺性状的遗传特征，本文选择了芒属植物中主要农艺性状上具有显著差异的荻（Micanthus.sacchariflorus）B0134和五节芒（M.floridulus）A0430种间杂交获得F₁群体，采用主基因+多基因混合遗传模型对F₁杂交群体的12个重要农艺学性状进行遗传和相关性分析。结果表明：F₁群体中的12个主要农艺性状呈连续的单峰、偏态分布，说明这些性状为多基因控制的数量性状；茎节数、主茎长、株高、分蘖数、单株重5个性状具有较大的中亲优势值，均达到极显著水平（P<0.01），中亲优势率30.65%~584.12%，其中分蘖数、单株重达到了极显著的超亲优势；混合遗传分析表明：叶长、叶宽、花序长和单茎重均由2对主基因+多基因控制；茎节数、株高、最大茎重由1对主基因控制；其他5个性状不存在主基因，只有多基因存在。12个农艺性状间存在一定的相关性，其中单株重与叶宽、分蘖数、单茎均重、最大茎重等产量相关性状存在极显著正相关，与叶片长和主茎长存在显著正相关（P<0.05），在荻和五节芒杂交种后代中选择高产单株时应特别注重对分蘖数性状的选择。

关键词: 荻, 五节芒, 主基因+多基因, 遗传分析, 相关性分析