红豆草营养枝水势日变化的研究

[目的]剖析红豆草水分生理特性,为红豆草的开发利用和耐旱特性的研究提供科学依据。[方法]测定了甘肃省西北民族大学榆中校区典型黄土高原半干旱地区红豆草营养枝(茎、叶、花)水势的日变化以及其含水率变化规律,研究了含水率在各个时间段的变化情况,水势日变化与温度、湿度、光照变化之间的相互关系。[结果]试验表明,红豆草营养枝水势与温度和光照呈负相关,而与湿度呈正相关。当温度为最低值18℃时,水势出现最高值-0.193 3 MPa,最低温出现在早晚;温度为最高值30℃时,则水势出现最低值-0.650 0 MPa,一般高温出现在一天中的14:00～16:00这段时间。当光照出现最低值8.8 lx时,水势出现最高值-0.193 33 MPa;当光照出现最高值105 448 lx时,水势出现最低值-0.650 0 MPa。当湿度出现最低值45%RH时,水势也出现最低值-0.650 0 MPa;当湿度出现最高值61%RH时,水势也出现最高值-0.173 33 MPa。一天中含水率高值出现在早上8:00、中午12:00、晚上20:00,低值出现在16:00～18:00,为74.37%～74.59%。[结论]红豆草营养枝水势与气象因子有密切关系。

Study on Daily Variation of Onobrychis viciaefolia Scop Vegetative Branches Water Potential

[Objective] To analyze physiological property of Onobrychis viciaefolia moisture and provide scientific basis for development and utilization of O.viciaefolia and drought-resistance characteristics.[Method] The daily variation of O.viciaefolia vegetative branches(stem,leaf,flower) water potential in typical Loess Plateau semi-arid region in Yuzhong Campus of Northwest University for Nationalities were determined,as well as its moisture variation law.The variation of moisture at different period,interaction between water potential daily variation and temperature,humidity,sunshine variation were studied.[Result] The results showed that the water potential indicates negative correlation with temperature and sunshine,and positive correlation with humidity.The maximum water potential-0.193 3 MPa appeared at the lowest temperature of 18 ℃ and illumination 8.8 lx,humidity 61%RH;the minimum water potential-0.650 0 MPa occurred at the highest temperature of 30 ℃ during 14:00-16:00,illumination 105 448 lx humidity 45% RH.High moisture content appeared at 8:00,12:00 and 20:00,low moisture appeared during 16:00-18:00 of a day,accounting for 74.37%-74.59%.[Conclusion] O.viciaefolia vegetative branches water potential have close relationship with meteorological factors.