Picloram-induced enhanced callus-mediated regeneration, acclimatization, and genetic clonality assessment of gerbera

Abstract

Background Gerbera jamesonii Bolus ex Hooker f. (African daisy) is listed among the top five most important ornamental plants in the global floricultural industry. To satisfy its demand, the floriculture industry relies on reproducible and effective propagation protocol while retaining the genetic uniformity of G. jamesonii. The present study, for the first time, reports the potential of picloram for enhanced induction of organogenic calli from leaves of G. jamesonii and its high-frequency indirect regeneration. Results The fastest induction of calli with maximum fresh and dry weight was recorded in the Murashige and Skoog (MS) semisolid medium supplemented with 1 mg/l picloram. In addition, callus induction was observed in 2,4-dichlorophenoxy acetic acid- and α-napthaleneaceticacid-supplemented media but with delayed response and reduced fresh and dry weight. The proliferated calli were transferred to shoot induction media containing MS salt and 0.5–1 mg/l N6-benzylaminopurine, kinetin, or thidiazuron. A mean number of ~6 shoots per callus were developed after 5 days of culture in the MS medium supplemented with 1 mg/l kinetin, with a mean length of 5.2 cm. Successful rooting of shoots was achieved in the MS medium fortified with 1.5 mg/l indole-3-acetic acid, wherein the earliest root initiation (~5 days), as well as the maximum number (~9) and length (~4.8 cm) of roots, were recorded. Complete plantlets were primarily acclimatized in sand before being transferred to a mixed substrate (of soil, sand, tea leaf waste, and cow urine) that secured >90% survival and further growth of the plantlets. Eventually, clonal fidelity of the in vitro regenerants assessed via inter-simple sequence repeats (ISSR) primers exhibited a monomorphic banding patterns that suggested genetic integrity within the plantlets as well as with their mother plant. Conclusions The results of the present study should be of interest for commercial propagation and mutagenesis- as well as genetic transformation-related research.

Optimized medium composition in Physalis alkekengi callus culture altered nitric oxide level for inducing antioxidant enzyme activities and secondary metabolites

“…For instance, Kashanchi et al 15 reported callus induction of P. alkekengi in 1/2 MS medium supplied with 2, 4-D (2 mgL −1 ), and organogenesis was observed during callus growth. Picloram at 1 mgL −1 concentration increased markedly days to callus induction and callus diameter in gerbera 21 and also, in combination with BAP (5 mgL −1 ), induced maximum callus formation in Simmondsia chinensis 22 , which may be associated with its impact on cell elongation and division through the responsive gene expressions 23 . However, in Eupatorium adenophorum , picloram stimulated electrolyte leakage and malondialdehyde productions and decreased callus biomass at high concentrations 24 .…”

Effects of various plant growth regulators upon callus induction potential using leaf explants of Clinacanthus nutans (Sabah Snake grass)

“…However, limited study had been carried out on callus induction in C. nutans (Bong et al, 2021;Hashim et al, 2021 andPhua et al, 2016) [24,[33][34] whereby callus study was carried out using limited plant growth regulators (2,4-D,Kinetin and BAP). To date, no callus study had been initiated using Picloram in C. nutans though many callus induction studies using Picloram had been reported in other medicinal plants (Gnasekaran et [35][36][37][38] . This is first study in C. nutans to induce callus using Picloram as one of the plant growth regulators.…”