Barstow Ashley C, Prasifka Jarrad R, Attia Ziv, Kane Nolan C, Hulke Brent S
Department of Plant Sciences, North Dakota State University, Fargo, ND, United States.
Sunflower and Plant Biology Research Unit, Edward T. Schafer Agricultural Research Center, United States Department of Agriculture (USDA)-Agricultural Research Service, Fargo, ND, United States.
Front Plant Sci. 2022 Dec 19;13:1056278. doi: 10.3389/fpls.2022.1056278. eCollection 2022.
Although high pollinator visitation is crucial to ensure the yields of pollinator-dependent crops, the quantitative trait loci (QTL) controlling nectar volume in sunflower ( L.), a pollinator preference trait, have yet to be identified. To address this, a recombinant inbred line mapping population, derived from lines with contrasting nectar volume, was used to identify loci responsible for the phenotype. As a result, linkage mapping and QTL analysis discovered major loci on chromosomes 2 and 16 that are associated with variation in nectar volume in sunflower. Increased nectar volume is also associated with increased sugars and total energy available per floret. The regions on chromosomes 2 and 16 associated with the nectar phenotype exhibit indications of chromosome structural variation, such that the phenotype is associated with rearrangements affecting regions containing hundreds of genes. Candidate genes underlying QTL on chromosomes 9 and 16 are homologous to genes with nectary function in . These results have implications for sunflower breeding, to enhance pollination efficiency in sunflower, as well as current and future studies on sunflower evolution.
虽然传粉者的频繁访花对于确保依赖传粉的作物产量至关重要，但控制向日葵（向日葵属）花蜜量这一传粉者偏好性状的数量性状位点（QTL）尚未得到鉴定。为了解决这一问题，一个由花蜜量具有显著差异的品系构建的重组自交系作图群体被用于鉴定与该表型相关的位点。结果，连锁图谱构建和QTL分析发现，2号和16号染色体上存在与向日葵花蜜量变异相关的主要位点。花蜜量的增加还与每朵小花中糖分和总能量的增加有关。2号和16号染色体上与花蜜表型相关的区域表现出染色体结构变异的迹象，因此该表型与影响包含数百个基因区域的重排有关。9号和16号染色体上QTL的候选基因与拟南芥中具有蜜腺功能的基因同源。这些结果对向日葵育种具有重要意义，有助于提高向日葵的授粉效率，也对当前及未来的向日葵进化研究具有重要意义。
