Effects of Depolymerized Gellan with Different Molecular Weights on the Growth of Four Bedding Plant Species

Abstract

New solutions allowing for the shortening of the growing cycle and improvements in plant quality are constantly sought in order to improve the efficiency of bedding plant production under covers. Biodegradable polysaccharides and their derivatives have become increasingly popular in horticulture as plant growth promoters. A greenhouse pot experiment was conducted to evaluate the effects of depolymerized gellan of different molecular weights (MW 56 kDa and 77 kDa) on the growth and physiological parameters of ornamental bedding plants Rudbeckia hirta L., Salvia splendens Sellow ex J.A. Schultes, Scabiosa atropurpurea L., and Tithonia rotundifolia (Mill.) S.F. Blake. The results showed that the application of depolymerized gellan accelerated flowering and stimulated the growth of all assessed species, regardless of MW. The plants treated with depolymerized gellan grew higher and had greater fresh weight of their above-ground parts, higher leaf relative chlorophyll content (SPAD; soil and plant analysis development), and higher stomatal conductance (gs). The use of 56 kDa gellan fraction resulted in the formation of inflorescences with the greatest fresh weight in S. atropurpurea. Leaves of R. hirta treated with this fraction showed the highest values of SPAD and gs. This study demonstrated that gellan derivatives of low MW may be used for the production of innovative plant biostimulants.

Enhancing Growth and Salinity Stress Tolerance of Pansy Using Hydrolyzed Gellan Gum – An Environmentally Friendly Plant Biostimulant

“…It was speculated that intensive photosynthesis due to HGG treatment could undoubtedly contribute to an increase in the number of flowers and biomass of the aboveground part of pansies (Table 1). The results obtained showing an apparent increase in relative chlorophyll content and stomatal conductance as a result of HGG application are confirmed by earlier studies (Salachna, 2020). The stimulating effect of HGG on chlorophyll biosynthesis and, consequently, 3).…”

“…The number of days to anthesis was not significantly affected by HGG treatments (data not shown). The stimulatory effects of depolymerized gellan gum with low molecular weight on growth parameters were found also in seedlings of annual ornamental plants (Salachna 2020). It is so important to find the optimal dose of biostimulant for specific species and even cultivars (Mpai et al, 2022;Kocira et al, 2017).…”

“…The plants were drenched with HGG solutions four times, starting in mid-February, every seven days, using 50 ml of HGG solution per plant each time. HGG with molecular weight of 56 kDa was prepared by acid hydrolysis (Salachna, 2020).…”

“…In the horticulture, gellan gum has been used in plant tissue culture media (Ishii et al, 1998;Kikuchi et al, 2023). Few studies to date show that gellan gum can exhibit biostimulatory effects on plants with the breakdown products of this biopolymer being more effective than the native form (Salachna et al, 2019;Salachna, 2020). However, the effects of depolymerized gellan on the growth habit, flowering and aesthetic appearance of floriculture crops grown under environmental stresses has not, as yet, been reported.…”

Evaluation of Carrageenan, Xanthan Gum and Depolymerized Chitosan Based Coatings for Pineapple Lily Plant Production

“…Biostimulants are a broad group of substances and microorganisms with high biological activity [3][4][5]. Of particular interest are biodegradable polysaccharides and their depolymerized derivatives exhibiting multi-directional actions in plants [6][7][8][9][10]. Chitosan is one of the best known natural polysaccharides with biostimulatory properties obtained in the process of chitin de-N-acetylation [11,12].…”