切花小菊主要分枝性状的配合力与遗传力分析

Combining Ability Analysis of the Major Branching Traits in Spray Cut Chrysanthemum

切花小菊的分枝性状是其株形和观赏品质的重要构成因素。研究切花小菊主要分枝性状的配合力,为杂交亲本合理组配提供依据。通过4×3不完全双列杂交,分析了7个切花小菊亲本及其F_1群体的总侧芽数、一级分枝数、一级分枝长度、一级分枝角度、二级分枝总数、二级分枝长度、二级分枝角度,共7个分枝性状的配合力效应和群体遗传参数。除总侧芽数主要受非加性效应控制外,其余6个分枝性状均主要受加性效应影响。各亲本在分枝性状上的一般配合力(GCA),以及不同组合的特殊配合力(SCA)和总配合力(TCA)差异较大。‘Monalisa’除一级分枝数的一般配合力为负值,其余各性状的均为正值,是培育疏散型新品种的优良亲本。‘Qx-021’(除二级分枝总数)和‘Qx-096’各分枝性状的一般配合力均为负值,是紧凑型新品种的优良亲本。杂交组合‘Qx-021’בQx-098’、‘Qx-081’בQx-098’的一、二级分枝数的总配合力较高,其余5个性状的总配合力均为负值,是选育紧凑型切花小菊的优良组合。7个分枝性状的广义遗传力均很高(73.81%～94.41%);除总侧芽数(1.88%)外,各分枝性状的狭义遗传力均在60%以上,受环境影响较小。

Branching is a major component trait of plant architecture and ornamental quality of spray cut chrysanthemum,and understanding of combining ability of major branching traits offers some references for parental selection in crossbreeding. In the present study,seven branching traits,i.e. total lateral bud number,primary branch number,primary branch length,primary branch angle,total secondary branch number,secondary branch length,and secondary branch angle of the twelve F_1 progenies derived from a 4 × 3 diallel design（NCII）were investigated to dissect the combining ability effects and other population genetic parameters. Combining ability analysis showed that total lateral bud number was controlled by non-additive genes;and the primary branch number,total secondary branch number,primary branch length and secondary branch length by both additive and non-additive genes;and the primary branch angle and secondary branch angle by additive genes. A great difference was observed for general combining ability（GCA）effects of parental cultivars and for different branching traits and the hybrid combinations with contrasting special combining ability（SCA）and total combining ability（TCA）effects. Especially,‘Monalisa＇exhibiting positive GCA for most branching traits except the primary branch number was capable of breeding cultivar with large plant architecture and loose branching type;whereas ‘Qx-021＇（except for secondary branch number）and‘Qx-096＇showing negative GCA for all investigated branch traits would be elite parents in crossbreeding targeting for cultivars of compact branching type. The crosses‘Qx-021＇בQx-098＇and‘Qx-081＇בQx-098＇showed high TCA for primary and secondary branch number but negative TCA for the other five branching traits,so it was likely to develop new cultivars of compact type from these crosses. In addition,a high level of broad-sense heritability ranging in 73.81%–94.41% was calculated for the seven branching traits,and a moderate high level of narrow-sense heritability larger than 60% was estimated for all the investigated branching traits except total lateral bud number（1.88%）. Findings of the current study reveal the combining abilities and genetic inheritance mode for the investigated branching traits and will be of vital importance for future efficient crossbreeding targeting plant architecture of spray cut chrysanthemum.