水分胁迫对蔓性千斤拔种子萌发和生理指标的响应

Response of water stress on seed germination and physiological characteristics of Flemingia philippinensis

利用不同浓度的聚乙二醇(PEG)模拟水分胁迫条件,测定蔓性千斤拔种子发芽率、发芽指数、平均发芽速度、苗长等萌发特性及渗透调节物质、保护酶活性等生理指标。结果显示,随着PEG浓度的增加,苗长受到明显抑制,发芽率影响不大,降低了平均发芽速度,在4%浓度范围内提高了发芽指数;可溶性糖、脯氨酸、可溶性蛋白含量呈上升趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性呈逐渐上升的趋势。这些结果表明,在一定的PEG胁迫浓度范围内,蔓性千斤拔种子萌发有较高的膜保护酶系统及渗透调节能力,并能不同程度的提高其萌发的整齐度。

Under the water stress simulatedby different concentrations of PEG,the seed germination rate,germination index, mean germination speed, seedling length and osmotic adjustment, protective enzyme activity of Flemingia philippinensis were investigated. The results showed that with the increase of PEG concentrations, seedling length was inhibited obviously but had little effect on germination rate, the mean germination speed was decreased, and the germination index increased under 4% of PEG. Soluble sugar, Pro and soluble protein content showed increasing trends, also the activities of superoxide dismutase（SOD）and peroxidas（POD）. These results illustrated that under certain PEG concentrations, the germinating F. philippinensis seeds had good membrane-protecting enzyme system and high osmotic adjustment capacity, which could improve the uniformity of the seed germination.