Bailes Emily J, Glover Beverley J
School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, United Kingdom.
Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom.
Flora. 2018 Jul;244-245:29-36. doi: 10.1016/j.flora.2018.06.005.
At a microscopic scale, the shape and fine cell relief of the petal epidermal cells of a flower play a key role in its interaction with pollinators. In particular, conical shaped petal epidermal cells have been shown to have an important function in providing grip on the surface of bee-pollinated flowers and can influence bee visitation rates. Previous studies have explored interspecific variation in this trait within genera and families, but naturally-occurring intraspecific variation has not yet been comprehensively studied. Here, we investigate petal epidermal cell morphology in 32 genotypes of the crop , which has a yield highly dependent on pollinators. We hypothesise that conical cells may have been lost in some genotypes as a consequence of selective sweeps or genetic drift during breeding programmes. We find that 13% of our lines have a distribution of conical petal epidermal cells that deviates from that normally seen in flowers. These abnormal phenotypes were specific to the ad/abaxial side of petals, suggesting that these changes are the result of altered gene expression patterns rather than loss of gene function.
在微观尺度上，花朵花瓣表皮细胞的形状和精细的细胞起伏在其与传粉者的相互作用中起着关键作用。特别是，已证明圆锥形的花瓣表皮细胞在为蜜蜂授粉的花朵表面提供抓地力方面具有重要功能，并且会影响蜜蜂的访花率。以往的研究探讨了属和科内该性状的种间变异，但自然发生的种内变异尚未得到全面研究。在这里，我们研究了这种产量高度依赖传粉者的作物32个基因型的花瓣表皮细胞形态。我们假设，由于育种计划中的选择性清除或遗传漂变，某些基因型中可能已失去了圆锥形细胞。我们发现，13%的品系中圆锥形花瓣表皮细胞的分布与正常花朵中所见的不同。这些异常表型特定于花瓣的正面/背面，表明这些变化是基因表达模式改变而非基因功能丧失的结果。
