ANATOMICAL AND PHYSIOLOGICAL CHARACTERISTICS OF PLANT RESISTANCE COMMON HORSE CHESTNUT AGAINST HORSE-CHESTNUT MINER MOTH

Abstract

Plant resistance against herbivores and pests is extremely complex multi-level system. It is caused by closely related constitutional grounds, physiological status, as well as the ability of a living organism to a rapid adjustment by external factors. The important component of plant resistance is the structure of the outer coating of tissues, that perform barrier function and prevent the pathogens penetration, lesions phytophages protect internal structures from excessive light, humidity and etc.

For conventional plants common horse chestnut (Aesculus hippocastanum L.) during the last 10 years, was causing  the damage by horse-chestnut leaf miner (Cameraria ohridella Deschka & Dimic (HCLM)) caterpillars,  that after the revival. Caterpillars penetrate the feed at first by leaf tissue and cell sap, and then feeds mesophyll cells. According to some researchers, common horse chestnut plant resistance against HCLM is associated with cuticle thickness of the upper epidermis. They also considered, that highly resistant plants of Aesculus L. was providing polyphenolic compounds. The most of them are synthesized in the chloroplasts and accumulated in vacuoles. According to our data, for HCLM resistant to conventional forms of common horse chestnut accumulation proanthocyanidins and other polyphenolic compounds in the leaves are  not important. On the contrary, it is shown that the resistant to the forms of plants against HCLM characteristic are the low concentration of catechins and proanthocyanidins. In this context, the target of this work was to study the features of the anatomical structure of leaves HCLM resistant to forms of common horse chestnut and determine the physiological state of assimilation system for quantitative and qualitative indicators plastid pigment content.

At the urban green areas of Kyiv, we found common horse chestnut resistant to HCLM forms. The unique of  this plantwhich is the ability to store assimilation surface intact during the growing season. We conducted comprehensive morphological and anatomical study and phytotochemistry investigation with aim to clarify the mechanisms of plant resistance against HCLM. They are shown that the resistant leaves to HCLM forms of common horse chestnut have typical macro and micromorphological structure. We have not been definedthe special features, that  differentiated them from other plants common horse chestnut. HCLM-resistant forms of common horse chestnut trees grow surrounded by plants that are heavily damaged by herbivores. So, the direct dependence of the resistance of plants to abiotic factors is little probable.

The leaves retain a characteristic shape and color from beginning to end of the growing season and show no outward signs of defensive reactions during 5-6 years. The  mikromines’ formation (first age caterpillars mines) on the leaf surface adaksial stable form common horse chestnut architectonics on the location and abundance of specific entities agreed butterfly laying eggs HCLM. It is obvious that resistant to HCLM forms of common horse chestnut not emit into the air specific repellents, that would scare away insects. At the same time plants are not disturbed synthesis ol-factors by these butterflies are finding the sources of fodder for caterpillars. It should be noted that the increased thickness of the cell wall takes a lot of energy costs on the way to the tracks vital cell sap. It was found that the traumatic injury leaf’s tissue surface plate of resistant forms of resistant to HCLM forms of common horse chestnut is accompanied by metabolic response associated with the synthesis of yellow - brown pigments.

The important difference in  resistance to HCLM forms of common horse chestnut has a high concentration of pigment that determines sized peaks. It was established that, plant’s pigments have individual pools with indicators Rf ~ 0,47, 0,78 and 0,98 were on 16, 7 and 41 times higher.

Thus, the degree of resistant to HCLM forms of common horse chestnut is determined by a complex structure - anatomical and biochemical characteristics, where the defining structure of cells of the upper epidermis and accumulation in vacuoles of polyphenolic compounds are determined. They prevent optimal power caterpillars immediately after their revival. Activation of the synthesis and condensation of phenolic compounds around the damaged sections on the leaf are confirmed the presence of resistance to HCLM forms of common horse chestnut with effective system of extracellular signalling providing formation induced immunity against HCLM plant organism and other potentially dangerous pathogens and herbivores.