低温胁迫对普通越冬栽培稻幼苗耐寒生理生化指标的影响

Effect of Low Temperature Stress on Physiological and Biochemical Indices of Cold Tolerance in Common Overwintering Cultivated Rice Seedling

研究不同越冬栽培稻种质资源的耐寒生理生化特性,为越冬栽培稻种质资源的创新利用提供理论依据。以20份普通越冬栽培稻种质为试验材料,测定并分析了常温(25℃)和低温(4℃)胁迫4 d后幼苗的叶绿素、丙二醛和SOD活性等5个耐寒生理生化指标。结果表明,正常生境下,20份普通越冬栽培稻种质幼苗期5个耐寒指标表现出不同程度的极显著差异。低温胁迫后,20份供试材料幼苗的5个耐寒指标发生了显著变化、同样表现出不同程度的极显著差异;各供试材料幼苗叶绿素和可溶性糖含量低温胁迫值较常温值均表现出显著的下降趋势,且它们的下降幅度不一致,分别为-36.46%~-90.31%,-70.54%~-94.03%。然而,丙二醛、脯氨酸和SOD活性3个耐寒指标低温胁迫值较常温值升降趋势不一致。其中,黄糯2号、晚粳糯M99037和常农粳3号丙二醛含量低温胁迫值较常温值显著降低,其余17份材料丙二醛含量值较常温值显著上升变化;铁粳稻4号、镇稻7号和津稻1187等8份材料脯氨酸含量低温胁迫值较常温值呈上升变化,其余12份材料较常温值呈下降变化。鄂晚稻15和津粳杂四幼苗SOD活性低温胁迫值较常温值略微下降、其余18份材料幼苗SOD活性值较常温值显著上升。正常生境下,各供试材料5个耐寒指标间仅检测到2对极显著相关性,低温胁迫后却检测到8对极显著相关,低温胁迫影响耐寒指标间相关性的数量、强度和方向。综合来看,无论在常温和低温胁迫后,20份普通越冬栽培稻幼苗5个耐寒指标因品种间遗传背景差异而表现出显著差异。

The physiological and biochemical indices of cold tolerance in common overwintering cultivated rice seedling were studied for providing theoretical basis for the innovation and utilization of overwintering cultivated rice germplasm.A total of 20 overwintering cultivated rice germplasms were selected as experimental materials,altogether five physiological and biochemical indices such as chlorophyll,malondialdehyde and SOD activity in rice seedling were measured and analyzed under both normal temperature(25℃)and 4 days of low temperature(4℃)stress.The five cold tolerance indices under normal temperature condition displayed extremely significant phenotypic differences among all tested materials from seven different provinces in China.The cold tolerance index such as chlorophyll and soluble sugar content apparently declined after chilling stress,but exhibited an inconsistent rate of decline among all experimental materials,ranged from-36.46%to-90.31%,-70.54%to-94.03%,respectively.While the cold tolerance indices such as malondialdehyde,proline and SOD activity in all tested rice seedlings displayed disparate response to cold chilling and exhibited an inconsistent rate of rising or falling.Among all tested materials,the malondialdehyde content in three tested materials such as Huangnuo 2,Wanjingnuo M99037 and Changnongjing 3 exhibited significantly decline after chilling stress,the remaining seventeen tested materials exhibited a significant rise.The proline content in eight tested materials such as Tiejingdao 4,Zhendao 7 and Jindao 1187 exhibited a significantly rising after being chilling stress,but the remaining twelve tested materials exhibited a significant decline malondialdehyde content value.The SOD activity in Ewandao 15 and Jinjingzasi exhibited an inconspicuous decline after chilling stress,while the SOD activity in the remaining eighteen tested materials exhibiteda significant rise.Only 2 pairs of extremely significant PCC values among the five cold tolerance indices were calculated under the normal temperature environment,while 8 pairs of extremely significant PCC values were calculated after chilling stress.Apparently,the number,strength and direction of correlations among the 5 cold tolerance indices were easily varied after chilling stress.On the whole,the cold tolerance indices in rice seedling under both normal temperature and low temperature exhibited significant difference owing to the different genetic background of overwintering cultivated rice.