Technogenic impact on physiological and cytogenic indices of reproductive organs of Tilia genus representatives

Abstract

This paper addresses the problem of technogenic pollution which is a dramatic stress-factor for plants effectively acting as a green filter for cleaning air, water, and soil. It results in their growth rate changes, seasonal development speed deviations and plant appearance variations. Green belt to consume industrial emissions and to create the esthetic look seems to be an urgent matter to deal with technogenic pollution. Lime tree decorative characteristics depend significantly on the state of their reproductive organs (flower, inflorescence and fruit). On the other hand, biometric indices of woody plant reproductive organs are sensitive parameters characterizing the plant response to pollutants. The study discusses complex environmental pollution impact caused by sulfur (IV) and nitrogen (IV) oxides as well as heavy metals on physiological and cytogenetic characteristics of reproductive organs of Tіlia L. genus representatives in conditions of steppe Prydniprovye. The research objectives were T . amurensis L. аnd T . cordаta Mill. Samples were collected in May and June 2014 on two sample areas. The research area borders with both heavy traffic road and Interpipe NTRP CJSC, Dnipropetrovsk, Ukraine, that features such pollutants as SO 2 , NO 2 , iron, manganese, zinc, mercury, chrome. The control area is located in the Botanical garden of Oles Honchar Dnipropetrovsk National University. The research proved that biometric and cytogenetic parameters of generic organo of Tilia genus representatives were dramatically sensitive to the impact of pollutants. Moreover, T. cordаta was the most sensitive among species under study to multicomponent environmental pollution when assessed by criteria of suppression of woody plant reproductive capacity formation. The other benefit of this study consisted in monitoring of the blossom rate of both species that appeared to scale down substantially in the technogenic environment. Man-induced stress factors caused lower rates of a range of lime generic parameters, for example, petal length and number of a model flowers. Besides, T. cordаta model flower had also the shorter stamen. The results obtained proved that technogenic environment undermined fertile ability of pollen grains of both research objects, though the most affected species was T. cordаta . The paper offers practical applications to complete environment phyto-indication and monitoring of condition of Tіlia genus plants with the help of the suggested test parameters (blossom rate and pollen-grain fertility (test object T. cordаta ) under conditions of constant influence of SO 2 , NO 2 and heavy metals.