Adventitious shoot regeneration from Sinningia speciosa leaf discs in vitro and stability of ploidy level in subcultures

Abstract

Leaf explants of SinningLa speciosa were cultured in vitro on Murashige and Skoog (MS) basal medium with various growth substances in order to regenerate shoots. On MS medium supplemented with indoleacetic acid (IAA) and kinetin, 80% of the explants produced green callus and 25 to 30 shoots with roots per explant. On MS supplemented with IAA and N 6 benzyladenine (BA), 80% of the explants produced green callus and 40 to 50 shoots per explaut but lacked roots. After 3-4 mo., these shoots were removed from the initial explants and transferred separately onto MS supplemented with indolebutyric acid for their elongation and successive rooting (3 too.). Histological studies showed that the callus was associated with mesophyll cell layers, primarily with the spongy parenchyma. The shoots regenerated at the callus surface and were associated with newly differentiated vascular areas. Recurrent regenerations were obtained from leaf explants or apical meristems excised from shoots of the previous subcultures. These explants, as compared to initial cultures, had a high frequency of regeneration and also produced more shoots per explant. Chromosome numbers of root tip ceils of the mother plant and of all in vitro-regenerated plants remained constant: 2n = 26.

Direct somatic embryogenesis and shoot organogenesis from leaf explants of Primulina tabacum

“…In the family Gesneriaceae, adventitious shoot regeneration from leaf discs and in vitro propagation in Sinningia spp. have been reported (Scaramuzzi et al 1999, Nhut et al 2005. Somatic embryogenesis and rapid multiplication in vitro has been reported in Chirita longgangensis (Tang et al 2007).…”

Tissue culture of Sinningia speciosa and analysis of the in vitro-generated tricussate whorled phyllotaxis (twp) variant

“…Previous studies have reported that leaf explants of S. speciosa initially form callus and adventitious buds in media containing BA and NAA, with subsequent roots produced on medium supplemented with NAA alone; moreover, the regenerated rates did not exceed 91.5% (Scaramuzzi et al 1999; Zhou et al 2000 ;Cao and Wang 2002). Most protocols report use of 0.3-4.0 mg l −1 BA with 0.01-0.2 mg l −1 NAA to induce calli, followed by a transfer to new medium containing 2.0 mg l −1 BA with 0.01-0.2 mg l −1 NAA to induce shoot differentiation (Scaramuzzi et al 1999;Zhou et al 2000;Cao and Wang 2002). These methods require two or more steps to obtain regenerated plants.…”

“…It is commonly known as gloxinia and is widely cultivated throughout the world as an ornamental horticulture crop due to its large, oval leaves and vibrantly colored, velvety, bell-shaped flowers (Sheehan and Tjia 1976;Scaramuzzi et al 1999;Nhut et al 2006;Brown 2007). However, it is difficult to obtain an abundance of healthy progeny, either by seed, due to self-sterility (Cao and Wang 2002), or by tubers (Scaramuzzi et al 1999). In vitro culture of plant organs or tissues have been accepted as an effective pathway to resolve this problem (Scaramuzzi et al 1999).…”

“…However, it is difficult to obtain an abundance of healthy progeny, either by seed, due to self-sterility (Cao and Wang 2002), or by tubers (Scaramuzzi et al 1999). In vitro culture of plant organs or tissues have been accepted as an effective pathway to resolve this problem (Scaramuzzi et al 1999). Although previous studies have developed regeneration systems of S. speciosa, there are several limitations, such as that the regeneration efficiency has yet to exceed 91.5%; the regeneration cycle takes over 2 mo; and the procedures use different kinds of media (Scaramuzzi et al 1999;Zhou et al 2000;Cao and Wang 2002;Pang et al 2006).…”

“…In vitro culture of plant organs or tissues have been accepted as an effective pathway to resolve this problem (Scaramuzzi et al 1999). Although previous studies have developed regeneration systems of S. speciosa, there are several limitations, such as that the regeneration efficiency has yet to exceed 91.5%; the regeneration cycle takes over 2 mo; and the procedures use different kinds of media (Scaramuzzi et al 1999;Zhou et al 2000;Cao and Wang 2002;Pang et al 2006). Recently, Nhut et al (2006) designed a tubeshaped nylon culture system for gloxinia and obtained a regeneration rate of 100%.…”