壳寡糖对水稻幼苗生长及抗逆性影响

Effects of oligochitosan on the growth and stress resistance of rice seedlings under abiotic stress

通过喷施分子量浓度为2000~3000壳寡糖溶液,分别研究低温、干旱和盐胁迫条件对水稻幼苗生长及抗逆性的影响。水稻幼苗分成1个正常对照组和8个处理组,其中,处理组分别喷施0、5、12.5、25、50、125、250和500 mg/L的壳寡糖溶液并进行逆境处理,定期采集叶片样本,测定抗逆生理指标。结果表明:施加壳寡糖浓度为25和50 mg/L时,低温下水稻的相对电导率较低,恢复正常条件24 h叶片相对电导率显著下降,恢复72 h幼苗茎高分别增加19.85%和24.40%,主根长分别提高49.50%和42.30%;恢复24 h,50 mg/L处理组叶片MDA含量显著下降。测定相对电导率结果表明,干旱和盐胁迫对水稻幼苗影响较大,12.5、25、50和25 mg/L处理组可降低干旱胁迫对水稻叶片的伤害,而25和50 mg/L浓度能缓解盐胁迫对水稻生长的不良影响。壳寡糖可提高水稻幼苗抗逆性并促进作物生长。

The effects of low temperature,drought,and salt stress on the growth and resistance of rice seedlings were studied by spraying different concentrations of oligochitosan with the molecular weight of 2000-3000.The rice seedlings were divided into one normal control group and eight treatment groups.The treatment groups were sprayed with 0,12.5,25,50,125,250 and 500 mg/L oligochitosan,respectively,the leaf samples were collected regularly,and then the physiological indicators were determined.The results indicated that the groups sprayed with 25 and 50 mg/L oligochitosan showed lower relative conductance in seedlings under low temperature stress.The leaf relative conductance decreased significantly after return to normal growth for 24 h.After the rice seedlings restored growth by low temperature stress for 72 h,its stem height increased significantly by 19.85%and 24.4%,respectively;and the main root length of it increased significantly by 49.50%and 42.3%,respectively.After return to normal growth for 24 h,the malondialdehyde(MDA)content in the treatment group sprayed with 50 mg/L oligochitosan was decreased significantly.By analyzing the leaf relative conductance,the results showed the rice seedlings were greatly affected by the drought and salt stress.The damage of drought stress to rice leaves could be decreased when the concentration of oligochitosan was 12.5,25,50 and 125 mg/L.Moreover,the negative effect of salt stress could be alleviated through spraying with 25 and 50 mg/L oligochitosan.In conclusion,not only the stress resistance,but also the growth of rice seedlings was improved by appropriate concentrations of oligochitosan.