Lourkisti Radia, Froelicher Yann, Herbette Stéphane, Morillon Raphael, Tomi Félix, Gibernau Marc, Giannettini Jean, Berti Liliane, Santini Jérémie
CNRS, Equipe de Biochimie et Biologie Moléculaire du Végétal, UMR 6134 SPE, Université de Corse, Corsica, France.
CIRAD UMR AGAP, Station INRA, Corsica, France.
Front Plant Sci. 2020 Apr 21;11:330. doi: 10.3389/fpls.2020.00330. eCollection 2020.
Low temperatures during winter are one of the main constraints for citrus crop. Polyploid rootstocks can be used for improving tolerance to abiotic stresses, such as cold stress. Because the produced fruit are seedless, using triploid scions is one of the most promising approaches to satisfy consumer expectations. In this study, we evaluated how the triploidy of new citrus varieties influences their sensitivity to natural chilling temperatures. We compared their behavior to that of diploid citrus, their parents (Fortune mandarin and Ellendale tangor), and one diploid clementine tree, as reference, focusing on photosynthesis parameters, oxidative metabolism, and volatile organic compounds (VOC) in leaves. Triploid varieties appeared to be more tolerant than diploid ones to natural low temperatures, as evidenced by better photosynthetic properties ( , ETR/ ratio), without relying on a better antioxidant system. The VOC levels were not influenced by chilling temperatures; however, they were affected by the ploidy level and atypical chemotypes were found in triploid varieties, with the highest proportions of -β-ocimene and linalool. Such compounds may contribute to better stress adaptation.
冬季低温是柑橘作物的主要限制因素之一。多倍体砧木可用于提高对非生物胁迫（如冷胁迫）的耐受性。由于所产果实无籽，使用三倍体接穗是满足消费者期望的最有前景的方法之一。在本研究中，我们评估了新柑橘品种的三倍体特性如何影响其对自然低温的敏感性。我们将它们的表现与二倍体柑橘、其亲本（福琼柑和埃伦代尔橘柑）以及一棵作为对照的二倍体克莱门氏小柑橘树进行比较，重点关注叶片中的光合作用参数、氧化代谢和挥发性有机化合物（VOC）。三倍体品种似乎比二倍体品种对自然低温更具耐受性，这一点从更好的光合特性（ ，ETR/ 比率）可以看出，且不依赖于更好的抗氧化系统。VOC水平不受低温影响；然而，它们受倍性水平影响，在三倍体品种中发现了非典型化学类型，其中 -β-罗勒烯和芳樟醇的比例最高。这些化合物可能有助于更好地适应胁迫。
