INFLUENCE OF FLOODING TEMPERATURE ON THE ROOT PENETRATION DEPTH AND POROSITY OF 2 VARIETIES OF WINTER-WHEAT

The problems connected with deficient aeration of plant roots can be s olved either by manipulating the environment to suit the plant or by a dopting the plant to suit the environment. The latter approach seems t o be more feasible and desirable from the environmental point of view. In this connection, the investigation of plant root porosity, being t he most important adaptive feature to unfavourable oxygenation conditi ons, seems to be of primary importance. The aim of our study was to in vestigate the air-filled porosity and the penetration depth of roots o f 20-day-old seedlings of two winter wheat varieties (Rosa and CZR 140 6) subjected to oxygenation stress at different temperatures. The 8-da y-old seedling stage of two leaves were subjected to differentiated ae ration conditions (control with pore water pressure about 15 kPa) and flooded for 12 days at three soil temperatures (7, 15, and 26 degrees C). The shoots of the seedlings were grown at a temperature of 26 degr ees C while the soil temperature was differentiated by keeping the cyl inders with the soil in thermostated water of the appropriate temperat ure. The flooding increased the root porosity in the entire temperatur e range under consideration. The interrelations between root porosity, root penetration depth, shoot biomass, and temperature are discussed.