不同光照强度下豆链格孢菌对白车轴草生理生化特性的影响

Effect of Alternaria azukiae on the physiological and biochemical characteristics of Trifolium repens under different light intensities

通过盆栽实验研究了不同光照强度下,接种豆链格孢菌(Alternariaazukiae(hara)comb.nov)对白车轴草(TrifoliumrepensL.)叶组织细胞膜透性、色素含量、丙二醛(MDA)含量、蛋白质含量、脯氨酸含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响。结果表明:豆链格孢菌使白车轴草叶组织细胞膜透性上升,电导率显著升高,膜脂过氧化加强,MDA水平上升,色素含量、蛋白质含量以及脯氨酸含量下降。随着处理光照强度的减弱,以上各生理指标的变化趋势更为明显,电导率和MDA含量均与光照强度显著负相关,而色素含量、蛋白质含量及脯氨酸含量均与光照强度显著正相关。接种豆链格孢菌后,色素含量明显下降,且弱光下(75%遮阳),豆链格孢菌对白车轴草叶片色素含量的影响更为明显,对照组的叶绿素a、叶绿素b、叶绿素(a+b)和类胡萝卜素含量均显著高于接种组的色素含量。在豆链格孢菌的刺激下,活性氧清除系统遭到破坏,保护酶系统失衡,其中SOD和CAT活性显著下降,而POD活性却明显上升,并且SOD、POD和CAT三种酶活性均与光照强度存在着明显的负相关系。

Pot cultivation experiments using different light intensities were used to study the effects of Alternaria azukiae （hara）comb. nov. on Trifolium repens L. , specifically on its cell membrane permeability, pigmentation, MDA, protein, and proline contents, and the activities of its SOD, POD, and CAT enzymes was shown that the infection of A. azukiae increased permeability of cell membrane, electric conductivity, over oxidation of cell membranes and MDA content, and decreased pigment, protein, and proline content in T. repens leaf tissue. With the decrease of the light intensity, the changes of the above-mentioned indices were more significant. The electric conductivity and the MDA content were negatively related to light intensity, the correlation coefficient were -0. 9957 and 0. 9942; whereas pigment ,protein and proline content were positively related to it. After inoculation with A. azukiae, the pigment content of the leaves of T. repens decreased notably, and under lower light （shaded to 75% of natural sunlight）, the effect of A. azukiae on the pigment content of T. repens leaves was greater than natural sunlight （100%）. The content of Chla,Chlb, Chl（a＋b） and Chlt in the controls was significantly higher than that of the inoculation. Due to the stimulation of A. azukiae, the activate oxygen metabolism system was destroyed, the balance of the protective enzyme system was broken, the activity of SOD and CAT decreased notably, comparative to anobvious increase in POD activity. At the same time ,the activities of SOD,POD and CAT were positively related to light intensity, with correlation coefficientsof 0. 9889,0. 9863 and 0. 9938.