The Morpho-Anatomy of Nectaries and Chemical Composition of Nectar in Pear Cultivars with Different Susceptibility to Erwinia amlylovora

The topography and morpho-anatomical characteristics of floral nectaries the chemical analysis nectar have been studied in seven pear cultivars with different susceptibility to Erwinia amylovora. susceptible cultivar Williams, moderately resistant Bella di guigno, Poire de Cure low Alexander Lucas originated from Pyrus communis, while highly Chojuro Nijisseiki P. pyraster Kieffer as interspecies hybrid communis × were included this experiment for first time. Large differences size structure observed these cultivars. epidermal cells cuticle being more or less striated Lucas, Williams. Resistant had a narrow, elongated cell shape those an isodiametric. Stomata mesomorphic all except slightly xeromorphic since they situated deep hollows. Guard modified stomata much larger Hypanthium compared most abundant sugars glucose, fructose, sorbitol sucrose (Chojuro, Nijisseiki) ~2-fold higher level galactose, ~2.2-fold isomaltose, ~2.7-fold turanose, ~3.35-fold maltose, ~4.4-fold melibiose ~12.7-fold melesitose sum quantified phenolic acids varied 0.049 (Williams) up 4.074 µg CAE/mL (Kieffer), flavonoid glycosides levels ranged 1.224 11.686 RE/mL (Nijisseiki). In cultivars, rutin, apigetrin, together patuletin luteolin detected but not which could be considered markers resistance.