不同种源马尾松幼苗对低磷胁迫的生理响应

对四川眉山(SM)、贵州孟关(GM)、广西桐棉(GT)、福建龙岩(FL)、福建武平(FW)、江西崇义(JC)及湖南汝城(HR)等7个种源的马尾松幼苗在轻度、中度和重度低磷胁迫下生理生化响应进行了研究.结果表明,在低磷胁迫下,不同种源马尾松幼苗叶绿素(a+b)含量呈下降趋势,其中FW下降幅度最大(65.0％),FL降幅最小(20.5％),而类胡萝卜素含量在低磷胁迫下变化较小;随低磷胁迫程度的增加,整体上马尾松幼苗可溶性糖含量逐渐增加,可溶性蛋白含量逐渐减少,游离脯氨酸含量则变化较复杂.其中,在重度低磷胁迫下,GT可溶性糖含量增加最大,较对照增加了38.9％,GM种源可溶性蛋白含量降幅最大,降低了49.5％,FW种源脯氨酸含量增加最大,为对照处理的3.5倍;MDA含量、POD、SOD及CAT活性等均在低磷胁迫下呈上升趋势,其中,SM种质在不同低磷胁迫间MDA含量无显著差异.除GT、JC及HR外,其余种源马尾松在轻度和中度低磷胁迫下根系活力上升.以上结果表明,马尾松通过降低叶绿素和可溶性蛋白含量以及根系活力,增加MDA、可溶性糖和游离脯氨酸含量,提高POD、SOD、CAT活性来应对低磷胁迫.

Physiological and Biochemical Responses to Low Phosphorus Stress for Different Masson Pine (Pinus massoniana) Provenances

The physiological and biochemical characteristics in seven different provenances of Pinus massoniana seedlings under mild,moderate and severe low-phosphorous stress were studied in the current work.Results showed that the content of chlorophyll (a + b) from different provenances decreased under low-phosphorous conditions,with the largest decline of 65％ in Fujian Wuping (FW) and lowest of 25％ in Fujian Longyan (FL),while slightly changes in the content of carotenoid.With the increase of low-phosphorous stress,the content of soluble sugar increased but the soluble protein decreased gradually in Pinus massoniana seedlings.However,complicated changes were found in the content of free proline,among which,the soluble sugar content of Guangxi Tongmian (GT) increased 38.9％ compared to the control,and the content of soluble protein in Guizhou Mengguan (GM) decreased mostly by 49.5％,the content of proline in FW increased as 3.5 times as the control.Furthermore,the content of MDA and activities of POD,SOD as well as CAT increased under low-phosphorus stress,and no significant difference existed in the content of MDA in Sichuan Meishan (SM) as subjected to different low-phosphorous treatments.Besides the Guangxi Tongmian (GT),Jiangxi Chongyi (JC) and Hunan Rucheng (HR),the root activity of Pinus massoniana seedlings increased under the mild and moderate low-phosphorus stress.Thus,we concluded that Pinus massoniana respond to low-phosphorus stress by reducing the content of chlorophyll,soluble protein and root activity,increasing the content of MDA,soluble sugar and free proline as well as the activity of POD,SOD,and CAT.