Assessment of the Effects of Some Bacterial Isolates and Hormones on Corm Formation and Some Plant Properties in Saffron (Crocus sativus L.)

Abstract

The saffron, from the Iridaceae family and an autumn-flowering geophytes, is one of cormous plants. The biggest obstacle in the development of this plant, production having the most economic value as one of the medicinal and aromatic plants, is the insufficient bulbous used for propagation. Bacterial isolates showing capacity to grow in nitrogen-free conditions, for hormones production (IAA, GA3) and to solubilise phosphate as microbial fertilizer were used to reproduce the corms of saffron plants. Thus, the disappearance of saffron from the species that are under threat of extinction can be prevented and the continuation of the species can be provided by its widespread propagation as an ornamental plant. In this study, a total of ten treatments; (1) Achromobacter xylosoxidans strain TV-42A, (2) Brevibacillus choshinensis strain TV-53D, (3) Myroides odoratus strain TV-85C, (4) Bacillus megaterium strain TV-87A, (5) Colwellia psycrerytreae strain TV-108G, (6) Kluyvera cryocrescens strain TV-113C and (7) Bacillus GC group B strain TV119E, (8) Control (untreated bacteria or hormones) (9) Control 2 [100 mg L-1 IBA (indole-3 butyric acid)] and (10) Control 3 [100 mg L-1 GA3 (gibberellic acid)] were tested to see their effects on the plant growth and development parameters of saffron. The number of cormlet, average cormlet diameter (mm), cormlet length (mm), cormlet weight (g), macro and micro plant nutrients (N, K, P, Mg, S, Ca, Na, Fe, Mn, Zn, Cu, Pb, B and Cd) contents of corms were determined in greenhouse assays. Some of the bacterial applications gave growth and yields of saffron equal to or higher than the hormones applied. Bio-fertilizers used in organic farming, increase in plant growth and development of saffron were concluded to have positive effect.