Viloria Z, Drouillard D L, Graham J H, Grosser J W
Assistant Professor, La Universidad Del Zulia, Departamento Botanica, Maracaibo, Edo. Zulia, Republica Bolivariana de Venezuela 4005ZU.
Senior Biological Scientist.
Plant Dis. 2004 Oct;88(10):1056-1060. doi: 10.1094/PDIS.2004.88.10.1056.
Resistance of citrus genotypes to Xanthomonas axonopodis pv. citri, the cause of Asiatic citrus canker (ACC), was evaluated by injection infiltration of 10 and 10 CFU/ml through stomates on the abaxial surface of immature leaves. Citrus genotypes for screening comprised two autotetraploids and nine triploid hybrids of 'Lakeland' limequat (Citrus aurantifolia × Fortunella japonica) and their progenitors ('Lakeland' limequat, the autotetraploids 'Femminello' lemon (Citrus limon) and 'Giant Key' lime (C. aurantifolia), and the somatic hybrids 'Key' [also known as 'Mexican'] lime + 'Valencia' orange and 'Hamlin' orange + 'Femminello' lemon). 'Meiwa' kumquat (Fortunella crassifolia) and 'Pineapple' sweet orange (C. sinensis) were used as known resistant and susceptible standards, respectively. Lesion number per inoculation site and bacterial population per lesion were recorded 15 to 19 days after inoculation. The assay was performed four times during a spring-summer-fall period under greenhouse conditions. Canker lesions were consistently produced by stomatal inoculation with 10 but not 10 CFU/ml. Susceptible and resistant genotypes were separated based on lesion number per inoculation site and bacterial population per lesion. Spearman's rank correlation analysis for lesion numbers on 15 genotypes common to all four assays showed significant correlations among the genotype rankings. Genotype rankings were also significantly correlated between the two bacterial population assays. Lesion number per inoculation site is sufficient for assessment of resistance of citrus genotypes to ACC without the necessity of conducting bacterial population assays. 'Lakeland' limequat is a promising seed parent for breeding acid citrus fruit that is resistant to ACC.
通过在未成熟叶片背面气孔注射接种浓度为10⁵和10⁷CFU/ml的柑橘溃疡病菌（引起亚洲柑橘溃疡病的病原菌），评估了柑橘基因型对柑橘溃疡病菌的抗性。用于筛选的柑橘基因型包括两个同源四倍体以及九个‘莱克兰’酸橙（Citrus aurantifolia × Fortunella japonica）三倍体杂种及其亲本（‘莱克兰’酸橙、同源四倍体‘费米内洛’柠檬（Citrus limon）和‘巨无霸’酸橙（C. aurantifolia），以及体细胞杂种‘墨西哥’酸橙 + ‘巴伦西亚’橙和‘哈姆林’橙 + ‘费米内洛’柠檬）。分别以‘梅湾’金橘（Fortunella crassifolia）和‘菠萝’甜橙（C. sinensis）作为已知的抗病和感病对照品种。接种后15至19天记录每个接种位点的病斑数和每个病斑的细菌数量。在温室条件下，于春 - 夏 - 秋期间进行了四次试验。通过气孔接种10⁵CFU/ml能持续产生溃疡病斑，但接种10⁷CFU/ml则不能。根据每个接种位点的病斑数和每个病斑的细菌数量区分出感病和抗病基因型。对所有四次试验共有的15个基因型的病斑数进行Spearman秩相关分析，结果表明基因型排名之间存在显著相关性。两次细菌数量测定的基因型排名之间也存在显著相关性。每个接种位点的病斑数足以评估柑橘基因型对亚洲柑橘溃疡病的抗性，无需进行细菌数量测定。‘莱克兰’酸橙是培育抗亚洲柑橘溃疡病酸性柑橘果实的一个有前景的亲本。
