L-β-苯基乳酸对小麦幼苗生长及生理的影响

Effects of L-β-phenyllactic acid on growth and physiological characteristics of wheat seedlings

【目的】探究L-β-苯基乳酸(LPA)在小麦幼苗生长中的调控作用及其适宜浓度水平,为LPA应用于小麦及其他作物生产提供参考依据。【方法】以小麦品种扬麦16为试验材料,以未添加LPA的1%MS营养液为对照组(CK),添加不同浓度LPA(10.0、100.0和1000.0 mg/L)的1%MS营养液为处理组,采用基质培养试验培养小麦幼苗,在培养的第7和14 d分别测定幼苗的株高和根长,叶片的叶绿素、可溶性总糖和可溶性蛋白含量及过氧化物酶(POD)和吲哚乙酸氧化酶(IAAO)活性等生理指标。【结果】与CK相比,添加不同浓度的LPA对小麦幼苗生长及其生理指标的影响效应呈低浓度(10.0~100.0 mg/L)增强、高浓度(1000.0 mg/L)减弱的规律。适宜浓度水平(100.0 mg/L)的LPA处理幼苗,培养至第7和14 d时的叶片主要生理指标均较CK显著提高(P<0.05,下同),其中叶绿素含量是CK的29.37和3.57倍,可溶性总糖含量是CK的1.50和2.69倍,可溶性蛋白含量是CK的3.00和4.33倍;IAAO活性显著降低96.64%和95.05%,POD活性显著降低75.69%和71.12%。【结论】LPA对小麦幼苗生长的调节效应类似于其他生长素,即低浓度(10~100 mg/L)促进生长、高浓度(1000 mg/L)抑制生长。以100 mg/L浓度处理的效果相对较好,可在小麦幼苗生产中推广应用。

【Objective】Regulation effects of L-β-phenyllactic acid(LPA)on growth of wheat and its suitable concentration were studied to provide reference for application of LPA in wheat and other crops.【Method】Wheat cultivar Yangmai 16 was used as materials.The control group was cultured in 1%MS nutrient fluid without LPA,and the treatment groups were cultured in 1%MS nutrient fluid with different concentrations of LPA(10.0,100.0 and 1000.0 mg/L).The wheat seedlings were planted by substrate culture.The plant height,root length,chlorophyll content,total soluble sugar content,soluble protein content,peroxidase(POD)activity and indoleacetic acid oxidase(IAAO)activity in leaves of the wheat seedlings were detected when the seedlings had been cultured for 7 and 14 d.【Result】Compared with CK,the low concentration(10.0-100.0 mg/L)LPA had more effect on growth and physiological indicators of wheat seedlings than the high concentration(1000.0 mg/L)LPA.After treatment of suitable LPA concentrations(100.0 mg/L),on day 7 and day 14,the main physiological indicators of leaf significantly increased compared with CK(P<0.05,the same below).Among the indicators,chlorophyll content was as 29.37 and 3.57 times as that of control respectively,total soluble sugar content was as 1.50 and 2.69 times as that of control,soluble protein content was as 3.00 times and 4.33 times as that of control.IAAO activity significantly reduced by 96.64%and 95.05%and POD activity significantly reduced by 75.69%and 71.12%.【Conclusion】The regulation effects of LPA on the growth of wheat seedlings are similar to that of other auxin.The low concentration LPA(10.0-100.0 mg/L)promotes growth of wheat seedlings,and the high concentration LPA(1000.0 mg/L)inhibits growth.Under this experiment condition,100 mg/L LPA achieves sound effects and can be promoted in wheat seedling cultivation.