作物学报2007，Vol.33Issue(2)：269-277,9.
土壤水分状况对小麦叶片超声波信号发射及木质部脆弱性的影响
Effects of Soil Water Conditions on Wheat Xylem Vulnerability and Leaf Ultrasound Acoustic Emission
摘要
Abstract
Water stress-induced xylem embolism has important physiological consequences for plant growth and survival in most species. Effects of soil water conditions on leaf xylem cavitation and embolism occurrence were investigated th roughout the major growth stages in field-grown winter wheat (Triticum aestiv um L. Cv. Shixin 733) plants. The xylem cavitation and embolism were measured by monitoring ultrasonic acoustic emission (AE) from leaf xylem. It was found that daily AE generally started around 6:00-8:00 a.m. And ceased between 21:00 p.m. And 3:00 a.m. Of the following day Embolism occurred to a much greater extent in leaves of water stress (WS) plants than in well-watered (WW) control. The total number of AE occurred in a period of 24 hours (24 h Aes) from WS plants was higher than that from WW control between jointing and mid grain fi lling stage. The difference between treatments peaked between anthesis and initial grain filling, with 24 h Aes being 4.6 times greater in WS than in WW plants The number of 24 h Aes from WS plants, however, dropped greatly to values si milar to oreven lower than that of WW plants under more severe soil water stress after mid grain filling, which phenomenon is termed "AE depletion" Vulnera bility curves, which were fitted to Logistic function by plotting cumulative Aes versus corresponding leaf water potential (Ψ1), showed that leaf xylem vessels were generally most vulnerable at Ψ1 of about -1.00 Mpa Soil w ater stress led to much more vulnerable leaf xylem, which greatly reduced leaf embolism resistance and consequently impaired xylem safety The higher degree of cavitation and embolism occurrence in WS plants resulted basically from a more vulnerable water conducting system, and much less from the greater xylem water tensions, as compared with WW control.关键词
木质部空穴化和气栓塞/叶水势/脆弱曲线/声发射/冬小麦Key words
Xylem cavitation and emboilsm/Leaf water potential/Vulnerability curves/Acous ticemission/Winter wheat分类
农业科技引用本文复制引用
贾秀领,王振林,马瑞崑,张丽华,张全国,杨利华..土壤水分状况对小麦叶片超声波信号发射及木质部脆弱性的影响[J].作物学报,2007,33(2):269-277,9.基金项目
Supported by the Natural Science Foundation of China(30370848), the Natural Science Foundation of Hebei Province(C2006000738), the National Key Program of Food Production promotion of China(2004BA520A07), and the Key Research Program of the Hebei Academy of Agricultural and Forestry Sciences, China(A03-1-02-14). （30370848）
