Istituto di Bioscienze e BioRisorse, Consiglio Nazionale delle Ricerche, Corso Calatafimi 414, 90129 Palermo, Italy.
Dipartimento di Scienze Agrarie e Forestali, Università degli Studi di Palermo, Viale delle Scienze, Ed. 4, 90128 Palermo, Italy.
Cells. 2021 May 28;10(6):1336. doi: 10.3390/cells10061336.
Polyploidy plays an important role in plant adaptation to biotic and abiotic stresses. Alterations of the ploidy in grapevine plants regenerated via somatic embryogenesis (SE) may provide a source of genetic variability useful for the improvement of agronomic characteristics of crops. In the grapevine, the SE induction process may cause ploidy changes without alterations in DNA profile. In the present research, tetraploid plants were observed for 9.3% of 'Frappato' grapevine somatic embryos regenerated in medium supplemented with the growth regulators β-naphthoxyacetic acid (10 µM) and N-benzylaminopurine (4.4 µM). Autotetraploid plants regenerated via SE without detectable changes in the DNA profiles were transferred in field conditions to analyze the effect of polyploidization. Different ploidy levels induced several anatomical and morphological changes of the shoots and mature leaves. Alterations have been also observed in stomata. The length and width of stomata of tetraploid leaves were 39.9 and 18.6% higher than diploids, respectively. The chloroplast number per guard cell pair was higher (5.2%) in tetraploid leaves. On the contrary, the stomatal index was markedly decreased (12%) in tetraploid leaves. The observed morphological alterations might be useful traits for breeding of grapevine varieties in a changing environment.
多倍体在植物适应生物和非生物胁迫方面起着重要作用。通过体细胞胚胎发生（SE）再生的葡萄植株的倍性变化可能为改良作物的农艺性状提供遗传变异的来源。在葡萄中，SE 诱导过程可能会导致倍性变化而不改变 DNA 图谱。在本研究中，观察到 'Frappato' 葡萄体细胞胚再生培养基中添加生长调节剂 β-萘氧基乙酸（10 μM）和 N-苄基氨基嘌呤（4.4 μM）时，有 9.3%的四倍体植株。通过 SE 再生的未检测到 DNA 图谱变化的同源四倍体植物被转移到田间条件下，以分析多倍化的影响。不同的倍性水平诱导了芽和成熟叶片的几个解剖和形态变化。气孔也发生了变化。四倍体叶片的气孔长度和宽度分别比二倍体高 39.9%和 18.6%。每个保卫细胞对的叶绿体数量也较高（5.2%）。相反，四倍体叶片的气孔指数明显降低（12%）。观察到的形态变化可能是在不断变化的环境中培育葡萄品种的有用特征。
