198 CUPRINS

It has been revealed that at low temperatures there is a delay of development of the parasite
and it did not affect the development of the hosts. High temperatures accelerate the development
of the parasite and increase the degree of its in uence on the hosts.
The in uence of different temperatures did not have an essential in uence on the degree
of infection in cases when F 1 hybrids were used, whereas, in their parental lines this in uence
was signi cant. The obtained results con rm a high adaptability of heterozygous genotypes to
environmental conditions.
Bibl. - 17, tab. - 2, g. – 3
UDC: 581.1.03:581.14.
HYDROSTATIC PRESSURE AND SUPEROXIDEDISMUTASE - TRIGGERS
OF NON SPECIFIC REACTION OF PLANTS ADAPTATION TO DROUGHT Ştefîrţă
Anastasia, Brînză Lilia. //Buletinul Academiei de Ştiinţe a Moldovei. Ştiinţele Vieţii. 2008, Nr.
3 (306), p. 37-47.
Features of water status regulation systems and oxidizing decomposition protective
enzymes involvement in triggering of non speci c reaction of plants to the drought are studied.
It is established, that change of the plant organism’s water status is primary at humidity shortage
and can cause not only appearance of active forms of oxygen as it is shown in numerous
researches, but also may be the trigger of cell’s switching from a normal activity to a stress
mode. Intensi cation of SOD activity that is the key enzyme of antioxidant systems at urgent
adaptation of plants to drought coincides with certain degree changes of hydrostatic pressure on
account of dehydration. It is supposed, that certain level of hydration is necessary for maximum
SOD activity, dehydration below the critical level causes inhibition of the enzyme and depends
on plants resistance.
Bibl. - 30, tab. - 2, g. – 3.
UDC: 581.1.036:633.872
ESTIMATION OF THE FLUFFY OAK (QUERCUS PUBESCENS WILD.) AND
PEDUNCULATA OAK (QUERCUS ROBUR L.) RESISTANCE TO INFLUENCE OF
HEAT. P.Cuza. //Buletinul Academiei de Ştiinţe a Moldovei. Ştiinţele Vieţii. 2008, Nr. 3 (306),
p. 48-56.
There have been investigated thermotolerance of leaves of a uffy oak (Quercus pubescens
Wild.) and a pedunculata oak (Quercus robur L.) to the action of various high temperatures
and duration of exposition. The damages of leaves caused by thermal stress have been de ned
by a method of electrolytes leakage. For studied oak species there has been observed a sigmoid
increase in level of electrolytes leakage from tests of leaves depending on in uence value of
the investigated temperatures. The curves describing character of damages of leaves which are
resulted have been caused by variation duration of an exposition of tests by a thermal shock.
Speci c reaction of the answer of leaves at the investigated kinds of an oak on in uence of
duration of a thermal shock was shown. Pedunculata oak leaves have appeared more sensitive
to in uence of heat in comparison with leaves of a uffy oak. Also the tendency of the better
retaining of electrolytes leakage of the pedunculata oak trees’ leaves, which had later terms
of leaves blooming in comparison with that of the uffy oak, at which leaves bloom earlier
was revealed. On the basis of the obtained results it is possible to conclude, that the method of
electrolytes leakage can be recommended for revealing of the distinctions between trees with
different terms of leaves blooming, and also between oak species according to the ability of
leaves to retain electrolytes under action of heat.
Bibl. – 13, Fig. – 4.
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