Application of biostimulants in tomato subjected to water deficit: Physiological, enzymatic and production responses

ABSTRACT The objective of this study was to evaluate the effect of the application of the biostimulants Seed+ and Crop+ on physiological and production variables and on the activity of antioxidant enzymes (superoxide dismutase - SOD and guaiacol peroxidase - POD) in tomato plants subjected to two soil water conditions. The experiment was carried out in a greenhouse, in a 2 x 2 x 6 factorial scheme, with two times of application of the biostimulants (flowering and fruiting), two soil water conditions (50 and 100% of soil water holding capacity) and six biostimulants (control treatment; Seed+; Seed+ + Crop+ 1x; Seed+ + Crop+ 2x; Crop+ 1x; + Crop+ 2x). The exprimental design was completely randomized, with four repetitions. The biostimulants Seed+ and Crop+ increased the quantum yield of photosystem II (Fv/Fm), regardless of the time of application and water condition of the soil. The biostimulants Seed+ + Crop+ 2x and Crop+ 2x stood out in the pre-morning period, with an average Fv/Fm of 0.813, under the conditions tested. The highest SOD activity (372.12 U mg-1 of protein) was obtained with Crop+ 2x biostimulant in fruiting and under water deficit. For POD, when under water deficit, the best results were obtained with the biostimulants Seed+ + Crop+ 2x, Crop+ 1x and Crop+ 2x in flowering (810.94; 691.19 and 921.59 U mg-1 protein) and in fruiting (703.60; 800.00 and 972.62 U mg-1 protein). Thus, the use of Seed+ and Crop+ biostimulants can be an alternative to help mitigate the damage caused by water deficit in tomato crop.

摘要 本研究旨在评估生物刺激素Seed+与Crop+的施用对两种土壤水分条件下番茄植株的生理指标、生产性状以及抗氧化酶（超氧化物歧化酶（superoxide dismutase，SOD）与愈创木酚过氧化物酶（guaiacol peroxidase，POD））活性的影响。本试验于温室中开展，采用2×2×6因子试验设计，设置2次生物刺激素施用时期（开花期与坐果期）、2种土壤水分条件（分别为土壤持水量的50%与100%）以及6种生物刺激素处理（空白对照；Seed+；Seed+ + Crop+ 1×；Seed+ + Crop+ 2×；Crop+ 1×；Crop+ 2×）。试验采用完全随机设计，设置4次生物学重复。无论施用时期与土壤水分条件如何，Seed+与Crop+生物刺激素均可提升光系统II量子产额（Fv/Fm）。在供试条件下，Seed+ + Crop+ 2×与Crop+ 2×处理在清晨前期表现最优，平均Fv/Fm值达0.813。在水分亏缺条件下，采用Crop+ 2×处理且于坐果期施用时，可获得最高的SOD活性（372.12 U·mg⁻¹ 蛋白）。对于POD活性，在水分亏缺条件下，于开花期施用Seed+ + Crop+ 2×、Crop+ 1×与Crop+ 2×处理分别可获得810.94、691.19与921.59 U·mg⁻¹ 蛋白的最佳效果；于坐果期施用上述三种处理则分别获得703.60、800.00与972.62 U·mg⁻¹ 蛋白的最佳效果。综上，施用Seed+与Crop+生物刺激素可作为缓解番茄栽培中水分亏缺所造成损伤的有效途径。