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Han Y.,Guizhou Pratacultural Institute | Lu X.,Beijing Forestry University | Li J.,Guizhou Pratacultural Institute | Zhao X.,Guizhou Pratacultural Institute | And 3 more authors.
Journal of Animal and Veterinary Advances | Year: 2012

The photosynthetic properties and photosynthetic responses to drought stress in the pot experiment of three chicory (Cichorium intybus L.) strains with different drought resistance, space-mutagenesis-bred strains PA-82 and PA-43 and their initial strain PA-57 were studied using Li-6400 portable photosynthesis system. The results showed that diurnal time courses of net Photosynthetic rate (Pn), Transpiration rate (Tr), stomatal Conductance (Cond) presented as double-peak curves. There was an obvious midday Pn depression, which was caused by nonstomatal factors. Highest Pn, Tr and Cond values were observed in PA-82 and lowest corresponding values in PA-43 (p<0.05). Intercellular C02 Concentration (Ci) of three strains showed an opposite course to that of Pn which reached its valley at 10:00-12:00. PA-82 had the highest Water Use Efficiency (WUE), followed by PA-57, thenPA-43. Light Saturation Points (LSP) of three strains were between 1207-1264 μmol/m2/sec and Light Compensation Points (LCP) were between 14.55-14.85 μmol/m2/sec, both indicating good adaptation to changes of light intensity. Pn, Tr, Cond, maximal photochemical efficiency of PS II in dark adaptation (Fv/Fm), potential photochemical efficiency (Fv/FO) and coefficient of Photochemical quenching (qP) decreased with the aggravation of water deficit. Among the three strains, the parameters of PA-43 dropped to a greater extent at a highest speed, followed by PA-57 then PA-82. With the aggravation of water deficit, Ci and co-efficient of nonphotochemical quenching (qN) increased to a greater extent at a highest speed in PA-43. The results suggest that PA-82 and PA-57 have higher resistance against severe water deficit in comparison with PA-43. © Medwell Journals, 2012.

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