Bioindication of thermotolerance of winter wheat(Triticum aestivum L.) photosynthetic apparatus

• Published in: Acta Fytotechnica et Zootechnica (Slovak Republic) Vol. 13; no. 3
• Main Authors: Brestič, M., Slovenská poľnohospodárska univerzita v Nitre (Slovak Republic), Fakulta agrobiológie a potravinových zdrojov, Katedra fyziológie rastlín, Olšovská, K., Slovenská poľnohospodárska univerzita v Nitre (Slovak Republic), Pivková, J, Slovenská poľnohospodárska univerzita v Nitre (Slovak Republic)
• Format: Journal Article
• Language: Slovak
• Published: 2010
• Subjects: ABIOTIC STRESS; CHLOROPHYLLE; CHLOROPHYLLS; CLOROFILAS; ESTRES ABIOTICO; FOTOSISTEMA 2; http://www.fao.org/aos/agrovoc#c_1577; http://www.fao.org/aos/agrovoc#c_34075; http://www.fao.org/aos/agrovoc#c_35768; http://www.fao.org/aos/agrovoc#c_7722; http://www.fao.org/aos/agrovoc#c_7951; PHOTOSYSTEM 2; PHOTOSYSTEME 2; STRESS ABIOTIQUE; TERMORREGULACION; THERMOREGULATION; TRITICUM AESTIVUM
• ISSN: 1335-258X

In a screening test for winter wheat (Triticum aestivum L.) thermotolerance 31 genotypes and landraces of different world proveniences were cultivated in a control environment of laboratory growth chamber. High temperature of 40 deg C was applied on leaf segments of all genotypes to induce increased heat sensitiveness or tolerance. A polyphasic enhancement of chlorophyll a fluorescence intensity up to 1 s (Kautsky induction curve) was measured before and after the heat treatment and a set of basic (Fo, Fm, Fv) and derived parameters of chlorophyll fluorescence was calculated from the induction curve. The results show that maximal photochemical PSII efficiency (Fv/Fm), relative variable fluorescence at 0.3 ms (Wk), performance index (P.I. abs) and effective energy dissipation from active reaction centers (DIo/CSo) were the most sensitive parameters to the applied high temperature and allowed to differentiate groups of studied wheat genotypes from the most heat sensitive (e.g. Slovak present genotypes) to the most heat tolerant (e.g. old Slovak landraces). Therefore the technique of chlorophyll fluorescence in a fast kinetics is useful for practical identification of more heat tolerant crops and other genetic resources, and in addition it can bring a lot of theoretical information about the heat effect on plant photosynthetic performance.