Zohreh Razmavar - Department of Horticultural Science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
Rohangiz Naderi - Department of Horticultural Sciences, University of Tehran, Tehran, Iran
Vahid Abdossi - Department of Horticultural Science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
Alireza Ladanmoghadam - Department of Horticultural Sciences, Garmsar Branch, Islamic Azad University, Garmsar, Iran
Fereshteh Nematollahi - Department of Chemistry, East Tehran Branch, Islamic Azad University, Tehran, Iran

Since edible flowers have been widely used to treat different diseases, new management practices are required to improve their productivity. Potassium (K) and selenium (Se) as important nutrients can influence plant quality and quantity. The purpose of present study was to investigate the effect of soil applied potassium (K) and selenium (Se) on plant growth, flower quality, and some physiological and biochemical properties of Pelargonium peltatum (L.) L'Hér. In a completely randomized design (CRD). K was used as potassium nitrate (KNO۳) in the concentrations of ۲, ۴, and ۶ mM and Se was applied as sodium selenite (Na۲SeO۴) in soil application of ۲۰, ۴۰, and ۶۰ µM. The results showed that the highest flower number was obtained at ۵ mM K. Shoot fresh weight (SFW) significantly increased by both ۶ mM K and ۴۰ µM Se. Flower longevity was improved with increasing K concentration so that the highest flower longevity was obtained at ۶ mM. The highest relative water content (RWC) and total chlorophyll (Chl.) content were observed at ۴ mM K. In contrast, the lowest RWC was observed when plants were supplied with ۶۰ µM Se. Anthocyanin and malondialdehyde ‎(MAD) significantly increased with K and Se concentrations. Although total phenolic compound (TFC) in all concentrations of K and Se was higher than control, there was no significant difference between K and Se levels. Ascorbic acid and phenylalanine ammonia-lyase (PAL) activity increased with K and Se application, in which its highest amounts were observed at ۶ mM K. P. peltatum was identified as Se accumulator because of more than ۱۰۰ mg Se/kg DW in the leaves when treated with Se levels. Heat map analysis represented that ۴ and ۶ mM K were obviously distinguished from other treatments. This experiment suggests using ۴-۶ mM K and ۴۰ µM Se to improve growth and productivity of P. peltatum.

Sodium Selenite, Potassium nitrate, Flower longevity, Phenolic contents, antioxidant capacity