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Start Over Coverage 561-568

2. Changes of leaf water potential and gas exchange during and after drought in triticale and maize genotypes differing in drought tolerance

Creator:
Grzesiak, M. T., Grzesiak, S., and Skoczowski, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
internal CO2 concentration, net photosynthetic rate, osmotic drought, stomatal conductance, transpiration, and Zea
Language:
Multiple languages
Description:
Influence of drought (D) on changes of leaf water potential (Ψ) and parameters of gas exchange in D-resistant and D-sensitive genotypes of triticale and maize was compared. Soil D (from -0.01 to -2.45 MPa) was simulated by mannitol solutions. At -0.013 MPa significant differences in Ψ, net photosynthetic rate (PN), transpiration rate (E), stomatal conductance (gs), and internal CO2 concentration (Ci) of D-resistant and D-sensitive triticale and maize genotypes were not found. Together with the increase in concentration of the mannitol solution the impact of D on E and gs for D-sensitive genotypes (CHD-12, Ankora) became lower than for the D-resistant ones (CHD-247, Tina). Inversely, impact of D on Ψ was higher in D-sensitive than D-resistant genotypes. From 1 to 3 d of D, a higher decrease in PN was observed in D-resistant genotypes than in the D-sensitive ones. Under prolonged D (5-14 d) and simultaneous more severe D the decrease in PN was lower in D-resistant than in D-sensitive genotypes. Changes in Ψ, PN, E, and gs caused by D in genotypes differing in the drought susceptibility were similar for triticale and maize. Compared to control plants, increase of Ci was different for triticale and maize genotypes. Hence one of the physiological reasons of different susceptibility to D between sensitive and resistant genotypes is more efficient protection of tissue water status in resistant genotypes reflected in higher decrease in gs and limiting E compared to the sensitive ones. Other reason, observed in D-resistant genotypes during the recovery from D-stress, was more efficient removal of detrimental effects of D. and M. T. Grzesiak, S. Grzesiak, A. Skoczowski.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. On the topological boundary of the one-sided spectrum

Creator:
Müller, Vladimír
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
math and topological boundary of the spectrum of an operator
Language:
English
Description:
It is well-known that the topological boundary of the spectrum of an operator is contained in the approximate point spectrum. We show that the one-sided version of this result is not true. This gives also a negative answer to a problem of Schmoeger.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

4. On torsionfree classes which are not precover classes

Creator:
Bican, Ladislav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
hereditary torsion theory, exact, noetherian and perfect torsion theory, Goldie’s torsion theory, precover class, cover class, and precover and cover of a module
Language:
English
Description:
In the class of all exact torsion theories the torsionfree classes are cover (precover) classes if and only if the classes of torsionfree relatively injective modules or relatively exact modules are cover (precover) classes, and this happens exactly if and only if the torsion theory is of finite type. Using the transfinite induction in the second half of the paper a new construction of a torsionfree relatively injective cover of an arbitrary module with respect to Goldie’s torsion theory of finite type is presented.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public