水分胁迫对尖果沙枣幼苗生物量及某些生理特性的影响

选取尖果沙枣1年生幼苗，盆栽于相对含水量不同的土壤中培养30d，研究尖果沙枣幼苗生物量及部分生理指标的变化。结果表明，土壤相对含水量在50％-55％时，与对照比，幼苗各指标无显著差异，这说明50％-55％的土壤相对含水量是适合尖果沙枣幼苗的生长；土壤相对含水量在35％-40％时，幼苗根冠比和叶绿素a含量明显增高，分别为0.596，35.920mg／cm^2，比对照幼苗分别增高了1.81倍和1.33倍，而其干物质积累率、膜透性、丙二醛含量、脯氨酸含量、叶片水势和叶片相对含水量与对照幼苗相比无显著差异，此时的土壤相对含水量可能是尖果沙枣幼苗能生长的阈值；土壤相对含水量在15％-20％时，幼苗干物质积累率和根冠比仍保持较高水平，而其叶片总重量和整株总生物量大幅度下降，chla／chlb比值也有明显降低，脯氨酸含量剧烈增高，叶片水势降低，叶片相对含水量大幅度下降，在这种低土壤相对含水量条件下，尖果沙枣幼苗虽然受到较严重的伤害，但仍然能够存活。

Effect of Water Stress on Plant Biomass and Several Physiological Characters of Elaeagnus oxycarpa Schlecht Seedlings

One year old Elaeagnus oxycarpa Schlecht seedlings were selected and planted in the pot with the deferent water content soils for thirty day,to study plant biomass and several physiological characters of Elaeagnus oxycarpa Schlecht seedlings. Results showed that. when the soil relative water content was 50%-55%,there were no significant difference on the every index of seedlings, 50%-55% soil relative water content maybe most fit to growth of Elaeagnus oxycarpa Schlecht seedlings. When 35%-40%, there is significant increase on root-crown ratio and chlorophyll a of seedlings,0.596,35.920 mg/cm^2 separately,increased by 1.81 and 1.33 times, respectively, compared with CK, but there were no significant difference on percentage of dry matter accumulation, membrane permeability, malondiadehyde content, proline content,water potential of leaves and leaf relative water content compared with the CK,35%-40% soil relative water content is maybe a limit of Elaeagnus oxycarpa Schlecht seedlings could growth no more harm. When the soil relative content is 15%-20%,percentage of dry matter accumulation and root-crown ratio are still keeping high levels,but the total leaf weight and total biomass decreased distinctly,chla/chlb ratio reduced significantly, proline content increased significantly, leaf water potential reduced and leaf relative water content decreased, under that soil relative water content situation,Elaeagnus oxycarpa Schlecht seedlings was hurt badly,but it was still alive.