Li Dawei, Xu Yuxian, Tang Yuchao, Zhou Tongjun, Li Hai, Guo Ziyu, Liang Yilin, Wang Yuxin, Chen Yuyuan, Sun Ming
State Key Laboratory of Efficient Production of Forest Resources, Beijing Key Laboratory of Ornamental Plants Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing 100083, China.
Plants (Basel). 2025 Apr 29;14(9):1338. doi: 10.3390/plants14091338.
Plant architecture is a crucial trait for ornamental plants. Chrysanthemum with prostrate growth habit is a novel cultivar group of ground-cover chrysanthemum, which have high ornamental value, strong lodging resistance, and outstanding landscape greening capability. To explore the genetic mechanism underlying the prostrate growth habit in chrysanthemum, we used tetraploid prostrate-type as the female parent and erect-type as the male parent to produce four generations (P, P, F, F). Five traits related to prostrate growth habit in chrysanthemum were investigated including plant height (PH), crown width of the plant (CP), creeping index (CI), gravitropic set-point angle (GSA), and growth habit (GH). The major gene plus polygene mixed inheritance analysis was conducted on five traits across four generations over two years. For the five traits, the coefficients of variation (CVs) were wide-ranging and high (16.64-42.75%), with the PH having the highest CV among them. Genetic analysis revealed that PH conformed to the additive-dominant-epistatic polygene model (C-0) and the model of two equally dominant major genes plus additive-dominant polygene (E-5). The most suitable genetic model for CI was an additive-dominant major gene plus additive-dominant-epistatic polygene model (D-0). The best-fit models for CP and GH were both C-0. For GSA, the best-fit models were E-4 and C-0. Additionally, it appeared that both genetic and environmental factors influenced the prostrate growth habit, as the heritability of major genes and polygenes was less than 50%. This study can serve as a theoretical foundation for the mapping of quantitative trait loci (QTLs) and further exploration of the genetic mechanisms underlying plant architecture in chrysanthemum.
株型是观赏植物的一个关键性状。具有匍匐生长习性的菊花是地被菊的一个新型品种群，具有较高的观赏价值、较强的抗倒伏能力和出色的景观绿化能力。为了探究菊花匍匐生长习性的遗传机制，我们以四倍体匍匐型菊花为母本，直立型菊花为父本，构建了四个世代（P、P、F、F）。对与菊花匍匐生长习性相关的五个性状进行了调查，包括株高（PH）、植株冠幅（CP）、匍匐指数（CI）、重力定点角（GSA）和生长习性（GH）。在两年时间内，对四个世代的五个性状进行了主基因 + 多基因混合遗传分析。对于这五个性状，变异系数（CV）范围广泛且较高（16.64 - 42.75%），其中株高的CV最高。遗传分析表明，株高符合加性 - 显性 - 上位性多基因模型（C - 0）以及两个等显性主基因加加性 - 显性多基因模型（E - 5）。匍匐指数最适合的遗传模型是加性 - 显性主基因加加性 - 显性 - 上位性多基因模型（D - 0）。冠幅和生长习性最适合的模型均为C - 0。对于重力定点角，最适合的模型是E - 4和C - 0。此外，由于主基因和多基因的遗传力均小于50%，似乎遗传和环境因素都对匍匐生长习性产生了影响。本研究可为菊花数量性状位点（QTL）的定位以及进一步探究其株型遗传机制提供理论基础。
