Exogenous Polyamines Improve Mycorrhizal Development And Growth And Flowering Of Freesia hybrida

Abstract

An experiment was conducted in order to investigate the effects of exogenous polyamines (PAs) on the development of mycorrhizae in roots, nutrient uptake and vegetative and reproductive growth ofFreesia hybrida‘Golden Wave’. Corms of freesia were inoculated withRhizophagus intraradicesat sowing time and treated once a week by one of three PAs, putrescine (Put), spermidine or spermine, in concentrations of 0.05 and 0.1 mM each as foliar application or soil drench. Application of PAs, especially as soil drench, increased mycorrhizal colonization as well as the growth and development of inoculated plants. Among the three PAs, Put in 0.1 mM concentration was the most effective in increasing colonization, enhancing floral stem length and diameter, floral spike length, floret number on main and lateral spikes and increasing corm and cormlet weight, corm diameter and cormlet number. Sole application of arbuscular mycorrhizal fungi had no significant effect on the flowering time but soil drench with 0.1 mM Put accelerated flowering by about 17 days. Application of PAs elevated leaves N, P, K, Mg, Fe and Zn and corms’ P, K, Ca, Fe and Zn concentration of inoculated plants. Our results suggest that soil drench application of PAs, especially Put, positively influenced mycorrhizal inoculation and nutrient uptake, which leads to improving growth, flower and corm production and quality of mycorrhizal plants of freesia.

Assessment of Different PGPR Formulations as a Biological Fertilizer in Cultivation of Poinsettia (<i>Euphorbia pulcherrima</i>)

“…It might also be due to positively affected by organic manure because chemically, organic manures add an organic compound to the soil. These findings are in conformity with those of [30] in Freesia and [17] in Hydrangea.…”

“…Gurung, et al [17] documented that the maximum stem thickness was observed in treatment T3 (Azotobacter + PSB + 80% RDF) in Hydrangea as compared to control. Also, Rezvanypour, et al [30] found that AMF (Arbuscular Mycorrhizal Fungi) inoculation caused significant increase in floral stem diameter for Freesia hybrida plants. The maximum stalk diameter of rose was recorded with Castor cake # 0.8 kg + Azotobacter # 1 ml + PSM # 1 ml + KSB # 1 ml / plant.…”

Mycorrhizal effector PaMiSSP10b alters polyamine biosynthesis in Eucalyptus root cells and promotes root colonization

“…Interestingly, while polyamines are detrimental to necrotrophic plant pathogens, the opposite appears to be true in the case of colonization by beneficial symbionts – particularly for mycorrhizal fungi. Polyamines increase in concentration during colonization of roots by AM (Sannazzaro et al ., 2007) and ECM fungi (Niemi et al ., 2006) while application of exogenous polyamines increases AM colonization (El Ghachtouli et al ., 1995; Wu & Zou, 2009; Rezvanypour et al ., 2015). Conversely, inhibition of polyamine formation reduces AM colonization (Wu et al ., 2010).…”

Arbuscular Mycorrhiza-Mediated Regulation of Polyamines and Aquaporins During Abiotic Stress: Deep Insights on the Recondite Players

“…This positive correlation between mycorrhizal colonization and PAs is validated by several studies. Based on their type and method of administration (soil drench or foliar application), PAs exerted their effectiveness on mycorrhizal (G. intraradices) development and concomitantly improved the quantity and quality of corm, and enhanced flower parameters in Freesia hybrida (Rezvanypour et al, 2015). The application of PAs in grape plants yielded beneficial effects on the infection rate, spore number, and hyphal growth of Gigaspora margarita, which are significantly reduced by the application of a PA biosynthetic inhibitor, methylglyoxal bis-guanylhydrazone (Yong et al, 2003).…”