Mohaghegh P, Khoshgoftarmanesh A H, Shirvani M, Sharifnabi B, Nili N
Department of Soil Science.
Department of Plant Protection.
Plant Dis. 2011 Apr;95(4):455-460. doi: 10.1094/PDIS-05-10-0379.
The effect of silicon nutrition on root rot of cucumber caused by Phytophthora melonis was studied in a greenhouse experiment. Two cucumber cultivars (Cucumis sativus 'Dominus' and 'Super Dominus') fertilized with three concentrations of Si (0.0, 1.0, and 1.7 mM Si in the form of sodium silicate) were not inoculated or were inoculated with P. melonis. The P. melonis isolate significantly decreased root dry weights, although the magnitude of growth reduction varied with cultivar and Si concentration. Silicon nutrition at either concentration significantly reduced disease severity relative to the treatment that received no silicon. There was a significant negative correlation between the extent of root rot caused by P. melonis and the extent of electrolyte leakage of roots. Roots infected with P. melonis had greater root catalase (CAT) and ascorbate peroxidase (APX) activities. There was a positive correlation between silicon concentrations and CAT and APX activities in plants inoculated with P. melonis. Silicon improved activity of antioxidant enzymes, resulting in enhanced crop resistance to oxidative stress induced by P. melonis infection and improved cucumber growth.
在温室试验中研究了硅营养对甜瓜疫霉引起的黄瓜根腐病的影响。用三种浓度的硅（以硅酸钠形式存在的0.0、1.0和1.7 mM硅）施肥的两个黄瓜品种（黄瓜‘Dominus’和‘Super Dominus’），一部分未接种甜瓜疫霉，另一部分接种了甜瓜疫霉。甜瓜疫霉分离株显著降低了根干重，尽管生长减少的幅度因品种和硅浓度而异。相对于未施硅的处理，两种浓度的硅营养均显著降低了病害严重程度。甜瓜疫霉引起的根腐程度与根电解质渗漏程度之间存在显著负相关。感染甜瓜疫霉的根具有更高的根过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性。在接种甜瓜疫霉的植株中，硅浓度与CAT和APX活性之间存在正相关。硅提高了抗氧化酶的活性，从而增强了作物对甜瓜疫霉感染诱导的氧化应激的抗性，并改善了黄瓜生长。
