Ploidy stability of somatic embryogenesis-derived Passiflora cincinnata Mast. plants as assessed by flow cytometry

Abstract

In this study, flow cytometric analysis was used to evaluate the genetic stability of Passiflora cincinnata Mast. plants regenerated via primary and secondary somatic embryogenesis. Embryogenic calli obtained from culturing zygotic embryos on Murashige and Skoog (MS) medium containing 18.1 lM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4 lM benzyladenine (BA) were transferred to differentiation medium. Torpedo and cotyledonary embryos were obtained. These primary embryos were maintained on differentiation medium to generate secondary embryos. Conversion of primary and secondary embryos yielded 305 and 138 normal plants, respectively. Almost 90% of plantlets survived following acclimatization. Flow cytometric analysis revealed that seed-derived plants had on average 3.01 pg nuclear DNA (2C), and all plants, except for a single plant regenerated via primary embryogenesis, maintained their ploidy. This single plant contained more than twice the average DNA content: 6.21 pg (4C). Epidermal stomata of leaves of the tetraploid plant were larger but lower in density than those of diploid plants, indicating that stomatal characteristics are useful in distinguishing between diploid and tetraploid plants of passion fruit. In summary, the procedure we employed to regenerated P. cincinnata plants via somatic embryogenesis generated mostly genetically true-to-type plants.

Embryogenic potential of immature zygotic embryos of Passiflora: a new advance for in vitro propagation without plant growth regulators

“…For both experiments (with and without 2,4-D), FEC formation started exclusively from the cotyledonary regions, resulting in the suppression of ZE germination, except in medium M1. This result is consistent with data obtained from other Passiflora species, such as P. cincinnata (Silva et al 2009;Pinto et al 2010), P. edulis (Pinto et al 2011;Rosa et al 2015), P. alata, P. crenata and P. gibertii (Rosa et al 2015). Therefore, cotyledons might be considered the segment of P. miniata and P. speciosa ZE with the highest embryogenic potential.…”

“…This phenomenon is termed somaclonal variation (Larkin and Scowcroft 1981). Distinct factors may induce these alterations during in vitro culture, such as the medium, type and concentration of growth regulators (Pinto et al 2010), genotype, explant type (Jain 2001) and time of culture (Silva and Carvalho 2013).…”

“…Cytogenetic (Mujib et al 2007;Clarindo et al 2012) and FCM (Pinto et al 2010;Clarindo et al 2012) techniques have been successfully applied to assess the karyotype and ploidy stability of in vitro regenerated plantlets in several species. FCM has been considered a rapid and efficient tool for detection of somaclonal variants, allowing to measure the ploidy level of a large number of samples in a short period of time (Bairu et al 2011).…”

COMBINATION OF NAA AND TDZ FOR In Vitro MULTIPLICATION OF Eugenia involucrata DC

“…The supplementation of the nutritive medium with these compounds often results in callus induction in E. involucrata (Golle, 2010) and other species, such as Morinda citrifolia (Baque et al, 2010), Hyptis leucocephala (Pereira et al, 2012), Litchi chinensis (Ma et al, 2009), and Passiûora cincinnata (Silva et al, 2009;Pinto et al, 2010).…”

Somatic embryogenesis of a wild passion fruit species Passiflora cincinnata Masters: histocytological and histochemical evidences

“…and bacterial canker (Xanthomonas campestris pv. passiflorae) (Oliveira and Ruggiero 2005). Commonly known as shark passion fruit, this species performs well in vitro, showing an elevated frequency of shoot-bud formation (Lombardi et al 2007;Dias et al 2009Dias et al , 2010Silva et al 2011).…”