秸秆焚烧土壤提取液对小麦种子萌发和幼苗生长的影响

Effects of Soil Extraction Solution of Burned Crop Straw on the Seed Germination and Seedling Growth of Wheat

采用水培法研究了秸秆焚烧土壤提取液对小麦种子萌发和幼苗生长的影响。结果表明,种子发芽势较秸秆焚烧前土壤提取液培养的种子明显提高,但种子发芽指数、发芽率和活力指数与焚烧前处理无差异;幼苗芽长、胚根长和须根数与秸秆焚烧前处理差异均不显著,但苗鲜重和苗干重均明显减少;种子萌发期α-淀粉酶活性较秸秆焚烧前处理明显下降,胚乳储藏物质转化率明显降低;幼苗叶片叶绿素和可溶性蛋白含量与秸秆焚烧前处理无显著差异,但净光合速率明显降低。这些结果揭示秸秆焚烧土壤对小麦种子萌发影响不大,但不利于小麦幼苗生长。

In order to investigate the effects of soil extraction solution ofburned crop straw on the seed germination and seedling growth of wheat, under the conditions of air temperature 25℃, non-light, the wheat seed were cultured by using distilled water (CK), extraction solution from soil of burned crop straw and soil of non-burned crop straw respectively. After 3 days, the germination energies of wheat seed were 85.55%, 88.23%and 83.35%, respectively. After 7 days, there no evident difference in the germination index (GI), germination percentage, vigor index (Ⅵ), the seedlings' lengths of bud and radical andfibrous root number between the soil of burned crop straw and non-burned cropstraw. On the contrary, the plant fresh weight and plant dry weight of wheat cultured in extraction solution from soil of burned crop straw decreased. During the germination of wheat seed, the transformation ratio of organic substance in endosperm and the α-amylase activity of wheat seed cultured in extraction solution from soil of burned crop straw reduced evidently compared with those cultured in extraction solution from soil of non-burned crop straw. The net photosynthesis rate was measured at air temperature 25 ℃, the light density 104 mol·m-2·s-1 for the 7th day's wheat seedlings cultured for 48 h. The net photosynthesis rate of wheat plants cultured in extraction solution from soil of burned crop straw decreased. The contents of chlorophyll a, chlorophyll b, total chlorophyll and the contents of soluble protein in wheat leaves cultured in extraction solutions from soil of burned crop straw and non-burned crop straw showedno evident difference. These results suggested that crop straw burning was harmless to seed germination, but unfavorable for the growth of wheat seedlings.