Song Chao, Acuña Tania, Adler-Agmon Michal, Rachmilevitch Shimon, Barak Simon, Fait Aaron
The Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
Albert Katz Department of Dryland Biotechnologies, French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
Hortic Res. 2022 Mar 14;9:uhac061. doi: 10.1093/hr/uhac061. eCollection 2022.
Grafting has been demonstrated to significantly enhance the salt tolerance of crops. However, breeding efforts to develop enhanced graft combinations are hindered by knowledge-gaps as to how rootstocks mediate scion-response to salt stress. We grafted the scion of cultivated M82 onto rootstocks of 254 tomato accessions and explored the morphological and metabolic responses of grafts under saline conditions (EC = 20 dS m) as compared to self-grafted M82 (SG-M82). Correlation analysis and Least Absolute Shrinkage and Selection Operator were performed to address the association between morphological diversification and metabolic perturbation. We demonstrate that grafting the same variety onto different rootstocks resulted in scion phenotypic heterogeneity and emphasized the productivity efficiency of M82 irrespective of the rootstock. Spectrophotometric analysis to test lipid oxidation showed largest variability of malondialdehyde (MDA) equivalents across the population, while the least responsive trait was the ratio of fruit fresh weight to total fresh weight (FFW/TFW). Generally, grafts showed greater values for the traits measured than SG-M82, except for branch number and wild race-originated rootstocks; the latter were associated with smaller scion growth parameters. Highly responsive and correlated metabolites were identified across the graft collection including malate, citrate, and aspartate, and their variance was partly related to rootstock origin. A group of six metabolites that consistently characterized exceptional graft response was observed, consisting of sorbose, galactose, sucrose, fructose, -inositol, and proline. The correlation analysis and predictive modelling, integrating phenotype- and leaf metabolite data, suggest a potential predictive relation between a set of leaf metabolites and yield-related traits.
嫁接已被证明能显著提高作物的耐盐性。然而，由于对砧木如何介导接穗对盐胁迫的反应存在知识空白，开发增强型嫁接组合的育种工作受到阻碍。我们将栽培品种M82的接穗嫁接到254个番茄种质的砧木上，并研究了与自嫁接M82（SG-M82）相比，嫁接植株在盐胁迫条件下（电导率EC = 20 dS m）的形态和代谢反应。进行了相关性分析以及最小绝对收缩和选择算子分析，以探讨形态多样性与代谢扰动之间的关联。我们证明，将同一品种嫁接到不同砧木上会导致接穗表型异质性，并强调了无论砧木如何，M82的生产效率。通过分光光度法分析脂质氧化发现，群体中丙二醛（MDA）当量的变异性最大，而最不敏感的性状是果实鲜重与总鲜重之比（FFW/TFW）。一般来说，除了枝条数量和野生种源砧木外，嫁接植株在所测性状上的值都比SG-M82大；后者与较小的接穗生长参数相关。在整个嫁接群体中鉴定出了高响应性和相关性的代谢物，包括苹果酸、柠檬酸和天冬氨酸，它们的变异部分与砧木来源有关。观察到一组由山梨糖、半乳糖、蔗糖、果糖、肌醇和脯氨酸组成的六种代谢物，它们始终是优异嫁接反应的特征。相关性分析和预测模型结合了表型和叶片代谢物数据，表明一组叶片代谢物与产量相关性状之间存在潜在的预测关系。
