Occurrence of somaclonal variation among somatic embryo‐derived white spruces (Picea glauca, Pinaceae)

Abstract

Four different variegata phenotypes were identified among 2270 white spruce plants [Picea glauca (Moench.) Voss.] produced over a period of 2 yr from the time of induction of embryogenic tissues. The four variegated plants differed from each other in the extent and distribution of chlorophyll-deficient needles. Light microscopy showed that variegated leaves of a selected variant consisted of a chimeral mixture of green and white cells. Electron microscopy showed that cells in completely white needles had large nuclei with predominant euchromatin, lacked large cytoplasmic vacuoles, and harbored vacuolized plastids with aberrant morphologies. Various observations suggest that the recovered variegata phenotypes reflect some kind of genetic instability of either chloroplastic or nuclear genomes. To elucidate the genetic basis of these variegata phenotypes in white spruce, three out of the four variants were subjected to randomly amplified polymorphic DNA (RAPD) analysis. Out of more than 250 RAPD markers screened, only one correlated with white needles of variegated plants. The nucleotide sequence of this DNA fragment showed no homology with any known gene, but the amplified sequence appears most likely of nuclear origin.

Screening RAPD primers to assess clonal fidelity in somatic embryos of Sawara cypress (<i>Chamaecyparis pisifera</i> Sieb. et Zucc.) and field performance of somatic embryo-derived trees

“…Similar results were reported using the RAPD technique in Norway spruce (Fourré et al 1997), Japanese black pine (Goto et al 1998), Japanese white oak (Thakur et al 1999), loblolly pine (Tang 2001), almond (Martins et al 2004), hazelnut (Nas et al 2004, pedunculate oak (Valladares et al 2006), cork oak (Fernandes et al 2011), apricot (Soliman 2012), annatto (Siril and Joseph 2013), and seedless lemon (Goswami et al 2013). In contrast, RAPD analysis reported genetic variation in poplar (Ostry et al 1994;Rani et al 1995), white spruce (Isabel et al 1995(Isabel et al , 1996, peach (Hashmi et al 1997), teak (Gangopadhyay et al 2003), Idaho locust (Ngezahayo et al 2006), stone pine (Cuesta et al 2010), and olive (Leva et al 2012).…”

Somaclonal Variation During Picea abies and P. omorika Somatic Embryogenesis and Cryopreservation

“…We hypothesized that both procedures used could negatively affect the genetic stability of plant material. Several studies have reported somaclonal variation in embryonic cultures both after in vitro cultivation and after cryopreservation (Burg et al, 2007;DeVerno et al, 1999;Helmersson et al, 2008;Nawrot-Chorabik, 2009;Isabel et al, 1996;Krajňáková et al, 2011;Dey et al, 2015). In this study we report substantial genetic instability in SSR genotypes of the studied material as 52 different mutation events in total were detected.…”

Frequency of somaclonal variation in plants of black spruce (Picea mariana, Pinaceae) and white spruce (P. glauca, Pinaceae) derived from somatic embryogenesis and identification of some factors involved in genetic instability

“…Somaclonal variation was also reported in somatic embryo-derived plants of conifers. Four P. glauca plants with variegata phenotypes were found among 2270 regenerated plants (Isabel et al, 1996). In this study, one out of 250 RAPD markers was correlated with the white needles of the variegated plants.…”