甜菜碱对低温胁迫下辣椒幼苗生理特性的影响

Effect of Betaine on Physiological Characteristics of Pepper Seedlings Under Low Temperature Stress

为了解外源甜菜碱对低温胁迫下辣椒幼苗生理特性的影响,本试验用10 mmol/L甜菜碱进行预处理,测定低温胁迫下幼苗中丙二醛(MDA)、可溶性蛋白、可溶性糖、脯氨酸的含量以及超氧化物歧化酶(SOD)活性等生理指标。结果表明,与低温对照(低温胁迫+喷蒸馏水)相比,在低温胁迫下叶面喷施10 mmol/L甜菜碱能使农乐大椒幼苗叶片中MDA含量降低1.020μmol/L,农乐大椒和正宗丘北辣幼苗叶片中可溶性蛋白含量分别增加11.5 mg/g和6.0 mg/g、可溶性糖含量分别增加49.614 mg/g和47.000 mg/g、SOD活性分别提高0.25 U/mL和1.75 U/mL、脯氨酸含量分别降低34.574 mg/g和6.377 mg/g。在低温胁迫下,农乐大椒的各项生理指标均显著高于正宗丘北辣。说明10 mmol/L甜菜碱预处理能有效缓解低温胁迫对本试验中2个辣椒品种幼苗造成的伤害,提高幼苗的抗寒能力,并且农乐大椒的耐寒性提高程度高于正宗丘北辣。

In order to understand the effect of exogenous betaine on the physiological characteristics of pepper seedlings under low temperature stress,10 mmol/L betaine was used to pretreat the seedlings,and the physiological indexes of the seedlings under low temperature stress were measured,such as malondialdehyde(MDA)content,soluble protein content,soluble sugar content,proline content and superoxide dismutase(SOD)activity.The results showed that compared with the low temperature control(low temperature stress+no spraying distilled water),foliar spraying of 10 mmol/L betaine under low temperature stress could reduce the MDA content in the leaves of Nongle pepper seedlings by 1.020μmol/L,increase the soluble protein content in the leaves of Nongle pepper and authentic Qiubei pepper seedlings by 11.5 mg/g and 6.0 mg/g respectively,increase the soluble sugar content in the leaves of Nongle pepper and authentic Qiubei pepper seedlings by 49.614 mg/g and 47.000 mg/g respectively,increase the SOD activity in the leaves of Nongle pepper and authentic Qiubei pepper seedlings by 0.25 U/mL and 1.75 U/mL respectively,and reduce the proline content in the leaves of Nongle pepper and authentic Qiubei pepper seedlings by 34.574 mg/g and 6.377 mg/g respectively.Under low temperature stress,the various physiological indexes of Nongle pepper were significantly higher than those of authentic Qiubei pepper.This indicates that pretreatment with 10 mmol/L betaine can effectively alleviate the damage caused by low temperature stress on the seedlings of the two pepper varieties in this experiment,improve the cold resistance of the seedlings.Moreover,the degree of improvement in cold resistance of Nongle pepper is higher than that of authentic Qiubei pepper.