Fire blight (Erwinia amylovora) is one of the biggest challenges in the production of quince (Cydonia oblonga Mill.) in Turkey, and the lack of effective control methods emphasizes the need for resistant varieties of this species; therefore, testing the susceptibility levels of the germplasm is necessary to create breeding programs that ensure resistance to this disease. The aim of our study was to determine the susceptibility levels of the Turkey quince germplasm. To that end, 56 genotypes were tested using three inoculation experiments in a climate-controlled greenhouse using a mixture of three virulent isolates. Resistance/susceptibility levels were determined according to the percentage of shoot length that was blighted (% SLB), which varied between 24.46 and 61.54%. The main effects of genotype and inoculations were statistically significant; interactions between genotype and inoculations were not, which indicated that genotypes developed different susceptibility responses independent of inoculations and greenhouse conditions. The results of the experiments were averaged, and the germplasms were grouped according to the Gardner scale as “resistant”, “medium susceptible”, and “susceptible” and divided into 6 groups (a-f) after statistical analyses. More detailed classification has been obtained by statistical analyses, so it is recommended that genotypes used in breeding studies must be classified statistically in addition to the classical classification. Genotype 2168 was the most resistant (24.69%) and had very similar SLB values in all experiments, which indicated that resistance is stable in only the most resistant genotypes. Ayva B 35 and Quince A rootstocks had 29.11 and 37.16% SLB, respectively. Altın 35 (28.58%), Ege 25 (30.49%), and Zeybek 35 (30.91%) cultivars and Ayva B 35 rootstock, which are developed through selection breeding, were found to be more resistant. The Turkey quince germplasm that was resistant to fire blight can be used as a breeding parent or registered as a fire blight resistant variety or rootstock. The results of this study have encouraged the onset of crossbreeding studies on fire blight resistance.

枯萎病（Erwinia amylovora）是木瓜（Cydonia oblonga）生产中的最大挑战之一。土耳其），并且缺乏有效的控制方法，这凸显了对该物种抗性品种的需求；因此，测试种质的敏感性水平对于建立确保对这种疾病具有抗性的育种计划是必要的。我们研究的目的是确定土耳其木瓜种质的敏感性水平。为此，在一个气候控制的温室中使用三种强毒分离株的混合物，通过三个接种实验测试了56个基因型。抗性/敏感性水平是根据枯萎的幼芽长度百分比（％SLB）确定的，介于24.46％和61.54％之间。基因型和接种的主要影响具有统计学意义；基因型和接种之间没有相互作用，这表明基因型产生了不同的敏感性反应，而与接种和温室条件无关。对实验结果取平均，根据加德纳量表将种质分类为“抗药性”，“中等易感性”和“易感性”，并经统计分析分为6组（af）。通过统计分析可以获得更详细的分类，因此，建议除了经典分类之外，还必须对育种研究中使用的基因型进行统计学分类。基因型2168是最抗药性（24.69％），并且在所有实验中的SLB值都非常相似，这表明抗药性仅在最具抗药性的基因型中稳定。Ayva B 35和Quince A砧木的SLB分别为29.11和37.16％。Altın35（28.58％），Ege 25（30.49％），发现通过选择育种培育的Zeybek 35（30.91％）品种和Ayva B 35砧木更具抗性。抗火疫病的土耳其木瓜种质可以用作育种亲本，也可以注册为抗火疫病的品种或砧木。这项研究的结果鼓励了关于抗白叶枯病的杂交研究的开始。