Cydonia oblonga Mill. (Rosaceae) leaves microrelief of Dagestan foothills forest phytocenoses

Cryo-scanning electron microscopy was used to study the micromorphology of the leaf surface of the wild-growing Cydonia oblonga Mill. (Rosaceae). The only habitat of wild-growing quince in Russia is the southern part of Dagestan. Mountain forest phytocenoses of Dagestan provide unique grounds for studying the adaptive potential of plants, since growing conditions change not only according to the change of seasons, but also directly depend on the altitude above sea level. The adaxial (upper) and abaxial (lower) surfaces of the studied samples have a number of micromorphological and microstructural features. The epidermis on the adaxial and abaxial sides differed not only in structural organization, but also in the specifics of surface micromorphology. The most striking feature of the micromorphology of the adaxial and abaxial sides of the leaf blade surface is cuticular folding in the form of microstrands on the main cells of the epidermis, as well as radial striations, peristomatic rings, and protrusions in the stomata region. Regardless of the habitat of fruit plants, their leaves were hypostomatous with anomocytic stomata of two types (primary and secondary), differing in qualitative and quantitative indicators. The primary stomata had a more prominent cuticular pattern and were also larger than the smaller secondary stomata. It should be noted that the presence of several types of cuticular folding, as well as stomatal polymorphism, are common features of other studied species of the subfamily Pyrinae, early Maloideae (Rosaceae). According to the data obtained, the identified features of cuticular folding are stable within the species and can be used as additional taxonomic characters.