Lu Zhaowen, Su Jiangshuo, Fan Honghong, Zhang Xuefeng, Wang Haibin, Guan Zhiyong, Fang Weimin, Chen Fadi, Zhang Fei
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095 China.
Zhongshan Biological Breeding Laboratory, Nanjing, 210014 China.
Mol Breed. 2024 Nov 4;44(11):75. doi: 10.1007/s11032-024-01518-0. eCollection 2024 Nov.
Chrysanthemums are versatile ornamental plants, and improving leaf and flower traits is an important breeding objective. Distant hybridization is a powerful method for plant breeding and genetic improvement, whereas the genetic basis in interspecific F progeny of chrysanthemums needs to be better understood for breeding purposes. In this study, the leaf and floral traits of the 273 reciprocal interspecific F hybrids of diploid (YSJ) and (JHN) were analyzed along with their SNP-derived genetic structure to elucidate the influence of differences in genetic background between the parents on the hybrid performance. We then performed a genome-wide association analysis (GWAS) to reveal the investigated traits' genomic loci and candidate genes. Considerable phenotypic variation (8.81% ~ 55.78%) and heterosis with transgressive segregation in both directions were observed in the reciprocal progenies. We observed a higher level of phenotypic variation in JHN × YSJ rather than in YSJ × JHN. Also, a significant reciprocal effect was observed for most examined traits. Based on the SNP data, we separated the hybrid progenies into three groups (I, II, and III), albeit imperfectly dependent on the cross directions, except for some reciprocal hybrids clustering into group II. Group I from YSJ × JHN and Group III from YSJ × JHN differed with contrasting and π ratios, indicating the genetic changes in the reciprocal populations. The outcome of GWAS via the IIIVmrMLM method detected 339 significant quantitative trait nucleotides (QTNs) and 40 suggestive QTNs, and the phenotypic variation explained by a single QTN ranged from 0.26% to 7.42%. Within 100 kb upstream and downstream of the important QTNs, we discovered 49 known genes and 39 new candidate genes for the investigated leaf and floral traits. Our study provides profound insights into the genetic architecture of reciprocal hybrid progenies of chrysanthemum species, facilitating future breeding activities.
The online version contains supplementary material available at 10.1007/s11032-024-01518-0.
菊花是用途广泛的观赏植物，改善叶片和花朵性状是重要的育种目标。远缘杂交是植物育种和遗传改良的有力方法，然而，为了育种目的，需要更好地了解菊花种间F代的遗传基础。在本研究中，分析了二倍体（YSJ）和（JHN）的273个正反交种间F杂种的叶片和花性状及其单核苷酸多态性（SNP）衍生的遗传结构，以阐明亲本间遗传背景差异对杂种表现的影响。然后，我们进行了全基因组关联分析（GWAS），以揭示所研究性状的基因组位点和候选基因。在正反交后代中观察到相当大的表型变异（8.81%~55.78%）和双向超亲分离的杂种优势。我们观察到JHN×YSJ的表型变异水平高于YSJ×JHN。此外，对于大多数检测性状，观察到显著的正反交效应。基于SNP数据，我们将杂种后代分为三组（I、II和III），尽管并不完全依赖于杂交方向，除了一些正反交杂种聚集在II组。YSJ×JHN的I组和YSJ×JHN的III组具有对比鲜明的θ和π比率，表明正反交群体中的遗传变化。通过IIIVmrMLM方法进行的GWAS结果检测到339个显著的数量性状核苷酸（QTN）和40个暗示性QTN，单个QTN解释的表型变异范围为0.26%至7.42%。在重要QTN的上下游100 kb范围内，我们发现了49个已知基因和39个新的候选基因，用于所研究的叶片和花性状。我们的研究为菊花种间正反交杂种后代的遗传结构提供了深刻见解，有助于未来的育种活动。
在线版本包含可在10.1007/s11032-024-01518-0获取的补充材料。
