Impact of jasmonates, salicylic acid, and fungal elicitor on the health of <i>Hippeastrum hybridum</i> bulbs achieved by <i>in vitro</i> procedure

Abstract

Production of high-quality vigorous plant materials obtained by micropropagation requires not only a good regeneration procedure but also efficient ways to enhance their post-transplanting ability to cope with external environmental factors. There is increasing interest in <i>Hippeastrum hybridum</i> on the horticultural market. However, the traditional method of cultivation using seeds and bulbs does not meet the growing demand and requirements of available priming procedures, thus leading to a search for more effective methods of reproduction. The aim of the study was to assess the morphogenetic abilities of bulb and flower explants for regeneration and investigate whether the enrichment of the multiplication process by exposure to elicitors will improve the health of the obtained plants through faster synthesis of phytoalexin. The study revealed that high regeneration efficiency can be obtained by using twin-scales, peduncles, and receptacles. Over 76% of explants were capable of bulblet induction and the micropropagation rates were 2.3, 2.7, and 5.0, respectively. At the rooting stage, the use of regulator-free medium was required, yielding a high percentage of rooted shoots of over 90% (shoots obtained on twin-scales and peduncles). The materials obtained <i>in vitro</i> did not differ morphologically from the initial materials. However, it was noted that, after exposure to the <i>Phoma narcissi</i> fungal elicitor or to jasmonic acid (JA) and jasmonic acid methyl ester (MeJA), the <i>in vitro</i>-derived bulbs were able to synthesize phytoalexin with higher efficiency than the untreated ones. Therefore, the described methods can be useful for <i>H. hybridum</i> multiplication. Moreover, the enrichment of the multiplication process with the stage of exposure to elicitors ensures initial immunity of <i>H. hybridum</i> to the pathogen <i>Phoma narcissi</i>, which can be used as a priming procedure.