壳聚糖对不同种源柠条种子发芽及其酶活性的影响

用不同浓度壳聚糖乙酸溶液分别对陕西省的吴起县和榆林市榆阳区两个产地的柠条种子浸种处理,以清水浸种处理为对照,调查种子发芽及幼苗生长特性,并测定了萌发过程中种子α-淀粉酶、脱氢酶、过氧化物酶、过氧化氢酶活性。结果表明,壳聚糖能促进柠条种子的萌发,缩短发芽时间;随着处理浓度的增大,各项发芽指标及各种酶活性先升高后降低,且不同种源柠条种子对壳聚糖浓度的反应不同。当壳聚糖浓度为0.5%时,榆阳柠条种子的发芽率是对照的1.2倍,平均发芽速率缩短0.9d,各种酶活性比对照显著提高,处理效果最佳。当壳聚糖浓度为1.0%时,吴起柠条种子发芽率比照提高13%,平均发芽速率缩短1.7d,各种酶活性比对照显著提高,处理效果最佳。当壳聚糖浓度达到1.5%时,对榆阳柠条种子的萌发有一定的抑制作用,而对吴起柠条种子萌发无抑制作用。壳聚糖对柠条幼苗的生长也有一定的影响,表现在幼苗的根长、苗高、干重、鲜重和叶绿素含量均显著高于对照,吴起柠条和榆阳柠条最佳的处理浓度分别为1.0%和0.5%。

Effect of chitosan on germination and enzyme activity of Caragana korshinkii Kom seed from different provenances

C. korshinkii seeds from two regions (Wuqi County, and Yuyang District in Yulin City) of Shaanxi Province were treated with acidic chitosan solution of different concentrations. Then the germination and seedling growth indices were investigated along with the activities of a-amylase, dehydrogenase, POD and CAT. Results show that chitosan improves seed germination and at the same time shortens germination time. With increasing chitosan concentration, germination indices and enzyme activities initially increase before decreasing under higher chitosan concentration. Seeds from different provenances respond differently to chitosan. When chitosan concentration is 0.5%, germination rate of seeds from Yuyang is 1.2 times that of CK, with mean germination time shortened by 0.9 d. Enzyme activities increase significantly compared with CK, producing the best enhancement effect. At 1.0% chitosan concentration, the germination rate of seeds from Wuqi increases by 13% and the mean germination time shortens by 1.7 d. Enzyme activities increase significantly compared with CK, producing the best enhancement effect. However, 1.5% chitosan concentration inhibits germination of seeds from Yuyang, but does not negatively impact germination of seeds from Wuqi. Chitosan generally improves growth of C. korshinkii seedling. Seedling root length, height, dry-weight, fresh-weight and chlorophyll content significantly increase. Optimum chitosan concentrations for seeds from Wuqi and Yuyang are respectively 1.0% and 0.5%.