不同水分处理对荚果蕨幼苗生长和生理特性的影响

以1年生荚果蕨幼苗为试验材料,采用称质量控制土壤含水量的方法,设置土壤质量含水率分别为田间持水量的50%～55%(T1)、>55%～60%(T2)、>60%～65%(T3),70%～75%(T4)、>75%～80%(T5)、>80%～85%(T6)6种处理,研究了荚果蕨幼苗的生长、叶绿素质量分数、光合作用以及脯氨酸和丙二醛的变化特性。结果表明:T4组荚果蕨幼苗的株高、营养叶枚数均高于其它5组;测定初期由于水分处理导致叶绿素质量分数升高,提高了荚果蕨对水分梯度的适应能力;不同水分处理下,荚果蕨幼苗净光合速率和蒸腾速率显著降低,抑制了荚果蕨幼苗生物量的积累。整个测定期间,T3组的脯氨酸质量分数最低,T1、T2的随着含水量的增大而逐渐减小且显著高于T3组,在渗透调节作用中起非常重要的作用;T4、T5和T6组脯氨酸质量分数随水分增大逐渐减小。测定初期,丙二醛质量摩尔浓度T3组最小,T1、T2明显大于T3组且2组持平。T4、T5、T6组随着水含量的增大而减小,但不明显。研究表明,荚果蕨不适应干旱的土壤水分环境,T3、T4处理(土壤质量含水率为28%～32%)是荚果蕨生长和生理特性最优的土壤质量含水率。

Effects of Different Water Treatments on the Growth and Physiological Characteristics of Matteuccia struthiopteris Seedlings

Six soil water stress treatments(50%-55%,55%-60%,60%-65%,70%-75%,75%-80%,80%-85% of field water capacity),denoted as T1,T2,T3,T4,T5 and T6,were set up using the weighing method to control soil moisture content.The change characteristics in growth,chlorophyll content,photosynthesis and proline content,and malondialdehyde(MDA) content of 1-year-old Matteuccia struthiopteris seedlings were studied.Results showed that the seedling height and the number of trophophylls per plant of T4 treatment were higher than those of the other five treatments.Chlorophyll content increased in the initial period of water treatment,which could enhance the adaptability of M.struthiopteris seedlings to different water gradients.The net photosynthetic rate and transpiration rate of M.struthiopteris seedlings significantly reduced under different water treatments,which inhibited the biomass accumulation.During the whole period of water treatment,the proline content of T3 treatment was the lowest,while those of T1 and T2 decreased with increasing water content,and they were both higher than that of T3.The proline contents of T4,T5 and T6 decreased gradually with increasing water content.The MDA content of T3 was the lowest in the initial period,while those of T1 and T2 were approximately equal,which were obviously higher than that of T2.The proline contents of T4,T5 and T6 decreased with increasing water content,but it was not obvious.Results show that M.struthiopteris seedlings are not accustomed to relatively dry soil moisture condition.The gravimetric water content of T3 and T4 treatments(28%-32%) is beneficial to the growth and physiological characteristics of M.struthiopteris seedlings.