新造地施磷深度对水分胁迫下苦荞抗氧化特性和产量的影响

Effect of Phosphorus Application Depth in Newly Planted Field on Antioxidant Properties and Yield of Tartary Buckwheat under Water Stress

采用根管土柱栽培的方法,研究不同水分胁迫(W1:正常供水;W2:中度干旱;W3:重度干旱)下施磷深度[距离地表10、20、30 cm施磷以及3层均匀施入磷肥(P10、P20、P30和P-all)]对苦荞盛花期根系抗氧化特性和产量的影响,以期为苦荞旱地栽培提供技术支持和理论依据。结果表明,水分胁迫、施磷深度及二者交互作用对苦荞盛花期根系抗氧化特性、产量及其构成因素均有显著或极显著影响。在盛花期,随着水分胁迫程度的增加,不同土层深度苦荞根系丙二醛(MDA)含量呈显著增加的趋势;超氧化物歧化酶(SOD)、过氧化物酶(POD)活性总体呈先升高后降低的趋势,以W2处理最高。与W1处理相比,W2处理0~10、10~20、20~30、30~45 cm土层根系SOD活性分别平均提高33.71%、42.62%、46.77%、41.32%,POD活性分别平均提高43.73%、41.55%、39.42%、42.03%。从不同施磷深度看,无论在哪种水分条件下,施磷均会提高施磷层苦荞根系SOD、POD活性,降低MDA含量,且深层施磷有利于本层以及下层根系抗氧化酶活性的提高,降低MDA含量。随着水分胁迫程度的增加,苦荞产量及其构成因素均呈显著下降的趋势,与W1处理相比,W3处理苦荞主茎分枝数、单株粒数、千粒质量、产量分别平均降低23.77%、35.30%、9.66%、14.13%。无论在哪种水分条件下,P20处理苦荞主茎分枝数、单株粒数、千粒质量、产量均达到最高值。综上,无论在哪种水分条件下,苦荞产量均以距离地表20 cm深处施磷处理(P20处理)最高,建议在旱作农业种植苦荞时通过适当深施磷肥,达到增产的目的。

Root canal and soil column cultivation method was used to study the effects of phosphorus application depth(10 cm,20 cm and 30 cm from the ground surface and 3 layers evenly,named as P10,P20,P30,P-all respectively)under different water stresses(W1:normal water supply;W2:moderate drought;W3:severe drought)on the antioxidant properties of roots at full blooming stage and yield of Tartary buckwheat,so as to provide technical support and theoretical basis for dry land cultivation of Tartary buckwheat. The results showed that water stress and phosphorus application depth and the interaction between them had significant or extremely significant effects on the antioxidant properties of roots at full blooming stage,yield and its components of Tartary buckwheat. At full blooming stage,with the increase of water stress degree,the molondialdehyde(MDA)content of Tartary buckwheat roots at different soil depths significantly increased,the activities of superoxide dismutase(SOD)and peroxidase(POD)increased first and then decreased,and W2 treatment was the highest. Compared with W1 treatment,the SOD activities of roots of W2 treatment in 0—10,10—20,20—30,30—45 cm soil increased by 33. 71%,42. 62%,46. 77%,41. 32%,respectively,and the POD activities increased by 43. 73%,41. 55%,39. 42%,42. 03%respectively. From the perspective of different phosphorus application depths,phosphorus application increased the SOD and POD activities of Tartary buckwheat roots in the phosphorus application layer,and reduced the MDA content;deep application of phosphorus was beneficial to increase the antioxidant enzyme activities of the roots in this soil layer and the lower soil layer,and reduced the MDA content. With the increase of water stress degree,the yield and its components of Tartary buckwheat significantly decreased. Compared with W1 treatment,the branch number of main stem,grain number per plant,thousand-grain weight and yield of Tartary buckwheat of W3 treatment decreased by 23. 77%,35. 30%,9. 66% and 14. 13% respectively. The branch number of main stem,grain number per plant,thousand-grain weight and yield of Tartary buckwheat of P20 treatment were the highest. In summary,the yield of Tartary buckwheat was the highest under P20 treatment,so we proposed the application of phosphorus fertilizer in a appropriate depth to increase the yield of Tartary buckwheat.