海藻糖对渗透胁迫下油菜种子萌发和幼苗生长的影响

25％PEG-6000渗透胁迫显著抑制油菜种子萌发和幼苗生长．使种子萌发推迟，发芽率降低22.67％，发芽指数降低112．8％，活力指数降低10．4倍，单株鲜质量、地上与地下部分鲜质量、地上和地下部分长度分别降低4．2，4．0g，4．82，4．19和1.42倍；25mmol／1。海藻糖（TH）处理能显著促进渗透胁迫下油菜种子萌发和幼苗生长．使种子发芽率提高14．67％，发芽指数提高33．12％，活力指数提高175．40％，单株鲜质量提高101．69％，地上、地下部分鲜质量和地上、地下部分长度分别提高62．38％，335．29％，25％和11．11％．

Effects of Trehalose on Seed Germination and Seedlings Growth of Rape under Osmotic Stress

Seeds and seedlings of rape cv.Yuhuang No.1 were treated with 25%PEG-6000 in combination with different concentrations(5 and 25 mmol/L)of trehalose(TH)and control to study the effects of ex- ternal TH on rape seed germination and seedlings growth under osmotic stress.The results showed that rape seed germination and seedlings growth were significantly inhibited in osmotic stress with 25% PEG- 6000.Under the osmotic stress,not only the germination was postponed,but also the germination rate, germination index and vigor index decreased by 22.67%,112.8% and 10.4 times,respectively,and the fresh weight of seedlings,shoots and root system,the length of shoots and root system decreased by 4.2, 4.09,4.82,4.19 and 1.42 times,respectively.However,the treatment of 25 mmol/L TH could enhance significantly rape seed germination and seedlings growth under osmotic stress.The germination rate,ger- mination index and vigor index increased by 14.67%,33.12% and 175.4%,respectively,and the fresh weight of seedlings,shoots and root system and the length of shoots and root system increased by 101.69%,62.38%,335.29%,25% and 11.11%,respectively.