Some ways of raising plants resistance to increased air temperatures in the conditions of biological and technical life support systems on the example of chufa cenoses (Cyperus esculentus L.)

The study is a part of the work on the assess-ment of resistance of vegetative link of artificial eco-logical systems to influence adverse factors of the environment. The work purpose is the definition of some ways of increasing stability of plants of chufa (Cyperus esculentus L.) to raised air temperatures. As the object of the research 30-day cenosis of chufa grown in the conditions of light culture with application of hydroponics method on expanded clay at PAR intensity of 690 μmol m-2 s-1 was taken, every 6 hours watering was carried out automatical-ly. Knop's solution, the solution 18 °С was used for watering. In the first series of experiments the influ-ence of temperature of root layer on the resistance of plants of chufa to the influence of air temperature of 45 °C within 44 hours at the illumination of 690 or 1150 μmol m-2 s-1 was estimated. Control plants were watered during thermal shock (TS) every 6 hours at PAR intensity of 690 μmol m-2 s-1 was estimated. Ex-perimental plants were watered each 3 hours. In the second series of the experiments the possibility of increasing heat stability of plants at the expense of preliminary hardening by step temperature increase with 25 to 40 °С (30; 35; 40 °С) certain air tempera-ture lasting influence of 1 hour was estimated. The duration of the subsequent TS made 20 hours at PAR intensity of 690 or 1150 μmol m-2 s-1. Heat stability of plants of chufa was estimated in parameters of ex-ternal CO2 of gas exchange. Performed experi-ments showed that the resistance of chufa cenoses to TS can be increased both due to the decrease in the temperature of root substratum and at the ex-pense of preliminary plants‟ hardening.