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Effects of Soil Moisture on Gas Exchange, Partitioning of Fed 14 CO 2 and Stable Carbon Isotope Composition (δ 13 C) of Leymus chinensis Under Two Different Diurnal Temperature Variations
Author(s) -
Xu Z. Z.,
Zhou G. S.
Publication year - 2005
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.2004.00119.x
Subject(s) - transpiration , diurnal temperature variation , stomatal conductance , water use efficiency , photosynthesis , water content , leymus , chemistry , soil water , rhizome , agronomy , carbon dioxide , δ13c , horticulture , stable isotope ratio , botany , biology , environmental science , grassland , soil science , atmospheric sciences , geotechnical engineering , organic chemistry , quantum mechanics , physics , engineering , geology , biochemistry
In a pot experiment under controlled condition, Leymus chinensis was grown at five soil water contents and two diurnal temperature variation levels. The leaf relative water content of L. chinensis decreased under soil drought conditions, and increased at high diurnal temperature variation (30/20 °C). Severe and very severe soil drought remarkably reduced photosynthetic rate, stomatal conductance, transpiration rate and water use efficiency (WUE), especially at the low temperature variation. Severe drought mainly increased the specific radioactivity of 14 C of sheaths, roots and rhizomes, but significantly decreased that of fed leaves and the not fully expanded leaves. Root percentage of total radioactivity remaining in the whole plant increased from 15 % at 30/25 °C to 28 % at 30/20 °C. Leaf carbon stable isotope composition ( δ 13 C) increased with soil drought, ranged from −26 ‰ of the well‐watered to −24 ‰ of severe drought treatments. High diurnal temperature variation improved leaf water status, and increased partitioning of carbon to root and δ 13 C values, especially under severe soil drought conditions. In conclusion, higher diurnal temperature variation enhanced the resistance of the plant to drought.