Effects Of Silicon Preparations On Physiological Characteristics Of Rice Seedlings In Cold Region Under Low Temperature Stress

Silicon has a positive effect on the growth and development of rice and can alleviate both biotic and abiotic stress in rice.Low temperature chilling injury is the primary meteorological disaster in China’s agricultural production.Northeast China is the area most seriously affected by low temperature chilling injury.Low temperature stress during growth will seriously affect the improvement of rice yield and quality.In this paper,Dongnong 427(cold tolerance)and Songjing 16(non-cold tolerance)rice were used as test materials,and four different types of Si-50G,Si-60G,Si-TG and Si-EG were sprayed at the seedling stage.Silicon preparation,and the two types of rice were treated with low temperature stress for 2 days,4 days,6 days,and 8 days,comparative analysis of different silicon preparation of rice seedling under low temperature stress of leaf photosynthetic pigment,malondialdehyde(MDA),proline,soluble sugar content and superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activity.This study provided scientific basis for the rational use of silicon preparation to enhance the ability of rice to resist low temperature stress,and had important theoretical and practical significance for ensuring the sustainable high and stable yield of rice in Heilongjiang province as well as the research and development of silicon fertilizer.Research indicates:(1)Silicon preparation has a positive effect on the increase of chlorophyll content in the leaves of rice seedlings under low temperature stress,and the effect gradually decreases with the increase of low temperature time.The effect is the best when the temperature is low for 2 days.The chlorophyll content of Songjing 16 treated with Si-50G,Si-60G,Si-TG and Si-EG is significantly increased by 40.17%,22.04%,31.30%and 35.42%compared with CK,respectively;Compared with CK,Dongnong 427 increases significantly by 27.11%,11.69%,6.16%,and 15.05%,respectively;Si-EG only has a positive effect on the increase of chlorophyll content in rice leaves under short-term low temperature stress(2-6 days).(2)Silicon preparation can significantly reduce the content of malondialdehyde in the leaves of rice seedlings.For Songjing 16,the content of MDA in the leaves treated with Si-50G decreases most significantly at 2 and 4 days of low temperature stress,which are 20.67%and 39.37%lower than those of CK,respectively.The aldehyde content is significantly reduced by 17.66%compared to CK;For Dongnong 427,the content of malondialdehyde in Si-TG treatment decreases the most significantly at 2 and 4 days of low temperature stress,which is 58.61%and 53.76%lower than that of CK,respectively.The most significant is 32.00%and 49.13%lower than CK,respectively.(3)Silicon preparation can significantly improve the antioxidant enzyme activity of rice under low temperature stress.For Songjing 16,under low temperature stress for 2,4,and 8 days,the POD activity of the leaves treated with Si-EG was the most significant,which increases by 73.58%,20.95%,and 217.24%,respectively,compared with CK.At 4 and 6 days of low temperature stress,the CAT activity of Si-EG treatment increases most significantly,which is 25.70%and 75.78%higher than CK,respectively;For Dongnong 427,the SOD activity of Si-60G-treated leaves increased the most at 4 and 8 days under low temperature stress,which is significantly increased by 58.15 and 82.76%compared to CK,respectively.At the 2nd and 8th day of low temperature stress,the POD activity of the leaves treated with Si-EG increased the most,significantly increased by 97.75%and 245.10%compared with CK,respectively.(4)Silicon preparation has a positive effect on the increase of proline and soluble sugar content in the leaves of rice seedlings under low temperature stress.For Songjing 16,the proline content of the leaves increases by 6-60 days under the low temperature stress of Si-60G,which is a significant increase of 196.11%compared with CK.The soluble sugar content of the leaves increases by 4 days,and the significant increase of 460.12%;For Dongnong 427,the content of proline in leaves of Si-TG treatment increases by 4 days at the lowest temperature,which is a significant increase of 79.99%compared with CK,and the soluble sugar in leaves of Si-50G treatment increases by 8 days at the lowest temperature,a significant increase of 125.57% compared to CK.