Citrus Research International, Mbombela 1200, South Africa.
Department of Genetics, Stellenbosch University, Stellenbosch 7600, South Africa.
Plant Dis. 2021 Feb;105(2):361-367. doi: 10.1094/PDIS-06-20-1259-RE. Epub 2020 Dec 10.
Determination of virus genomes and differentiation of strains and strain variants facilitate the linkage of biological expression to specific genetic units. For effective management of stem pitting disease of citrus tristeza virus (CTV) by cross-protection, an understanding of these links is necessary. The deliberate field application of a biological agent such as a virus first requires a thorough assessment of the long-term impact before it can be applied commercially. Three CTV sources were genetically characterized as different variants of the T68 strain, and their long-term effects on stem pitting and production were investigated. The different CTV sources were inoculated to 'Star Ruby' grapefruit trees and evaluated for a number of biological parameters in a field trial in the Limpopo Province of South Africa over a 10-year period. Significant differences were observed in stem pitting severity, impact on tree growth, yield, and the percentage of small fruit produced. These T68 variants were also associated with different stem pitting phenotypes. The variants differed in only 44 nucleotide positions across their genomes, and these minor genetic differences can therefore be used to identify possible genome regions affecting stem pitting.
确定病毒基因组以及菌株和株系变体的分化有助于将生物学表现与特定的遗传单位联系起来。为了通过交叉保护有效管理柑橘衰退病毒（CTV）的茎陷斑病，有必要了解这些联系。在商业应用之前，必须对生物制剂（如病毒）的长期影响进行彻底评估，然后才能进行实地应用。对三种 CTV 来源进行了遗传特征分析，结果表明它们是 T68 菌株的不同变体，并且研究了它们对茎陷斑病和产量的长期影响。将不同的 CTV 来源接种到“Star Ruby”葡萄柚树上，并在南非林波波省进行了为期 10 年的田间试验，评估了许多生物学参数。在茎陷斑病严重程度、对树木生长、产量和小果比例的影响方面观察到了显著差异。这些 T68 变体也与不同的茎陷斑病表型有关。这些变体在其基因组中仅存在 44 个核苷酸位置的差异，因此这些微小的遗传差异可用于鉴定可能影响茎陷斑病的基因组区域。
