Kārkliņa Katrīna, Lācis Gunārs, Lāce Baiba
Institute of Horticulture, Graudu 1, LV-3701 Dobele, Latvia.
Plants (Basel). 2021 May 20;10(5):1024. doi: 10.3390/plants10051024.
European pear rust is an important disease; however, the relationship between its causal pathogen (Dicks.) Oerst. and host L. is poorly understood. In this study, disease severity was measured, and leaf samples were collected over three years, and their leaf water content; leaf area; leaf mass per area; and epidermis, mesophyll, and vascular tissue width and stomatal density were measured and compared between susceptible and resistant genotypes for each year. Most genotypes either showed consistent disease symptoms or showed no symptoms during the study in terms of their susceptibility. A correlation between disease severity and mesophyll tissue thickness, and stomatal density and differences between several morphological parameters were found depending on the genotype's susceptibility. The study showed that the following pear morphological traits were stable between the years: water content, leaf mass per area, spongy mesophyll thickness, phloem thickness, and stomatal density. When selecting for breeding, we found that candidates for traits that discern susceptible genotypes from resistant were mesophyll layer width, stomatal density, epidermis width, and xylem tissue width.
欧洲梨锈病是一种重要病害；然而，其致病病原菌（Dicks.）Oerst.与寄主L.之间的关系却鲜为人知。在本研究中，对病害严重程度进行了测定，并在三年间采集了叶片样本，测量了其叶片含水量、叶面积、单位面积叶质量以及表皮、叶肉和维管组织宽度和气孔密度，并对每年感病和抗病基因型之间进行了比较。在研究期间，大多数基因型要么表现出一致的病害症状，要么没有症状，这取决于它们的易感性。根据基因型的易感性，发现病害严重程度与叶肉组织厚度、气孔密度以及几个形态参数之间存在相关性。研究表明，以下梨形态特征在不同年份之间是稳定的：含水量、单位面积叶质量、海绵状叶肉厚度、韧皮部厚度和气孔密度。在进行育种选择时，我们发现能够区分感病基因型和抗病基因型的性状候选指标是叶肉层宽度、气孔密度、表皮宽度和木质部组织宽度。
