Alves Mônica N, Lopes Silvio A, Raiol-Junior Laudecir L, Wulff Nelson A, Girardi Eduardo A, Ollitrault Patrick, Peña Leandro
Fundo de Defesa da Citricultura, Araraquara, Brazil.
Empresa Brasileira de Pesquisa Agropecuária, Cruz das Almas, Brazil.
Front Plant Sci. 2021 Jan 8;11:617664. doi: 10.3389/fpls.2020.617664. eCollection 2020.
Huanglongbing (HLB) is the most destructive, yet incurable disease of citrus. Finding sources of genetic resistance to HLB-associated ' Liberibacter asiaticus' (Las) becomes strategic to warrant crop sustainability, but no resistant genotypes exist. Some relatives of the family Rutaceae, subfamily Aurantioideae, were described as full-resistant to Las, but they are phylogenetically far, thus incompatible with . Partial resistance was indicated for certain cross-compatible types. Moreover, other genotypes from subtribe Citrinae, sexually incompatible but graft-compatible with , may provide new rootstocks able to restrict bacterial titer in the canopy. Use of seedlings from monoembryonic species and inconsistencies in previous reports likely due to Las recalcitrance encouraged us to evaluate more accurately these relatives. We tested for Las resistance a diverse collection of graft-compatible Citrinae species using an aggressive and consistent challenge-inoculation and evaluation procedure. Most Citrinae species examined were either susceptible or partially resistant to Las. However, and Papua/New Guinea species as well as their hybrids and those with arose here for the first time as full-resistant, opening the way for using these underutilized genotypes as Las resistance sources in breeding programs or attempting using them directly as possible new Las-resistant rootstocks or interstocks.
黄龙病（HLB）是柑橘类最具毁灭性且无法治愈的病害。寻找对与黄龙病相关的“亚洲韧皮杆菌”（Las）具有遗传抗性的来源，对于确保作物可持续性具有战略意义，但目前不存在抗性基因型。芸香科柑橘亚科的一些近缘种被描述为对Las完全抗性，但它们在系统发育上距离较远，因此与柑橘不亲和。某些交叉亲和类型表现出部分抗性。此外，柑橘亚族中其他与柑橘有性不亲和但嫁接亲和的基因型，可能会提供能够限制树冠中细菌滴度的新砧木。单胚物种幼苗的使用以及先前报告中可能由于Las顽固性导致的不一致性，促使我们更准确地评估这些近缘种。我们使用一种积极且一致的挑战接种和评估程序，对多种嫁接亲和的柑橘亚族物种进行了Las抗性测试。大多数被检测的柑橘亚族物种对Las敏感或部分抗性。然而，越南柑橘和巴布亚新几内亚柑橘物种以及它们的杂种，还有与宽皮橘杂交的类型，首次在此被发现具有完全抗性，为在育种计划中利用这些未充分利用的基因型作为Las抗性来源，或尝试直接将它们用作可能的新型Las抗性砧木或中间砧开辟了道路。
