CNRS, Équipe de Biochimie et Biologie Moléculaire du Végétal, UMR 6134 SPE, Université de Corse, Corsica, France.
UCA, INRAE, PIAF, Clermont-Ferrand, France.
Sci Rep. 2021 Apr 26;11(1):8902. doi: 10.1038/s41598-021-88383-5.
Nutrient deficiency alters growth and the production of high-quality nutritious food. In Citrus crops, rootstock technologies have become a key tool for enhancing tolerance to abiotic stress. The use of doubled diploid rootstocks can improve adaptation to lower nutrient inputs. This study investigated leaf structure and ultrastructure and physiological and biochemical parameters of diploid common clementine scions (C) grafted on diploid (2x) and doubled diploid (4x) Carrizo citrange (C/CC2x and C/CC4x) and Citrumelo 4475 (C/CM2x and C/CM4x) rootstocks under optimal fertigation and after 7 months of nutrient deficiency. Rootstock ploidy level had no impact on structure but induced changes in the number and/or size of cells and some cell components of 2x common clementine leaves under optimal nutrition. Rootstock ploidy level did not modify gas exchanges in Carrizo citrange but induced a reduction in the leaf net photosynthetic rate in Citrumelo 4475. By assessing foliar damage, changes in photosynthetic processes and malondialdehyde accumulation, we found that C/CM4x were less affected by nutrient deficiency than the other scion/rootstock combinations. Their greater tolerance to nutrient deficiency was probably due to the better performance of the enzyme-based antioxidant system. Nutrient deficiency had similar impacts on C/CC2x and C/CC4x. Tolerance to nutrient deficiency can therefore be improved by rootstock polyploidy but remains dependent on the rootstock genotype.
营养缺乏会改变生长和高质量营养食品的生产。在柑橘作物中，砧木技术已成为增强对非生物胁迫耐受性的关键工具。使用双二倍体砧木可以提高对低养分投入的适应性。本研究调查了叶结构和超微结构以及二倍体普通克莱门氏小柑橘接穗（C）嫁接到二倍体（2x）和双二倍体（4x）卡里佐克莱门氏小柑橘（C/CC2x 和 C/CC4x）和克里曼丁橘 4475（C/CM2x 和 C/CM4x）砧木在最佳施肥和 7 个月养分缺乏后的生理生化参数。砧木的倍性水平对结构没有影响，但在最佳营养条件下，诱导了 2x 普通克莱门氏小柑橘叶片中细胞数量和/或大小以及一些细胞成分的变化。根砧木的倍性水平没有改变卡里佐克莱门氏小柑橘的气体交换，但诱导了克里曼丁橘 4475 的叶片净光合速率降低。通过评估叶片损伤、光合作用过程变化和丙二醛积累，我们发现 C/CM4x 受养分缺乏的影响小于其他接穗/砧木组合。它们对养分缺乏的耐受性更强可能是由于基于酶的抗氧化系统的更好表现。养分缺乏对 C/CC2x 和 C/CC4x 有类似的影响。因此，通过砧木多倍体可以提高对养分缺乏的耐受性，但仍然取决于砧木基因型。
