Strawberry (Fragaria × ananassa)

Abstract

Genetic transformation in strawberry (Fragaria spp.) can be achieved by using the Agrobacterium-mediated procedure on leaves from in vitro proliferated shoots. Regardless of the sufficient regeneration levels achieved from leaf explants of some commercial strawberry genotypes, the regeneration of transformed strawberry plants remains difficult and seems to be strongly genotype dependent. In fact, the main factors that play an important role in the success of strawberry genetic transformation are the availability of an efficient regeneration protocol and of an appropriate selection procedure of the putative transgenic shoots. The strawberry genetic transformation protocol herein described relates to three genotypes resulted from our experience with the highest regeneration and transformation efficiency. The study includes two octoploid Fragaria × ananassa cultivars, Sveva and Calypso, and a diploid F. vesca cultivar (Alpina W.O.). All the different steps related to the leaf tissue Agrobacterium infection, coculture, and selection of regenerating adventitious shoots, as well as the following identification of selected lines able to proliferate and root on the selective agent (kanamycin), will be described.

The use of TDZ for the efficient in vitro regeneration and organogenesis of strawberry and blueberry cultivars

“…4b). So, the efficiency of TDZ in inducing indirect organogenesis observed in strawberry (Landi and Mezzetti 2006;Cappelletti et al, 2015) was also observed in blueberry.…”

“…Adventitious shoot regeneration from in vitro cultured explants of cultivated strawberries has been demonstrated for a variety of tissues. Leaf discs remain the most successful and widely used regeneration explant (Nehra et al, 1990;Sorvari et al, 1993;Cappelletti et al, 2015). In addition many other starting tissues have been tested such as: petioles (Focault and Letouze 1987;Rugini and Orlando 1992), stipules (Rugini and Orlando 1992), stem tissues (Graham et al, 1995) runner tissue (Liu and Sanford 1988), the peduncular base of the flower bud (Focault and Letouze 1987), mesophyll protoplast (Nyman and Wallin 1988), anther cultures (Owen and Miller 1996), roots (Rugini and Orlando 1992) and immature embryos (Wang et al, 1984).…”

Establishment of a Rapid and Stable Transgenic System by Agrobacterium-Mediated Transformation of the Germination Seeds in Diploid Strawberry.

“…In addition to the widely-used leaf-disk transformation [14,19,20], other tissues are also used for gene transformation21-30. The mature and immature embryo-generated calli are used to develop transgenic plants in rice, maize, wheat and Barley [21][22][23]27].…”

Establishment of A Rapid and Stable Infected System by Agrobacterium-Mediated Transformation of Germination Seeds in Diploid Strawberry.

“…In addition to the widely-used leaf-disk infection [14,19,20], other tissues are also used for gene infection [21][22][23][24][25][26][27][28][29][30].…”

“…It is previous reported that some factors including suspension Agrobacterium concentrations, Agrobacterium infection time, kanamycin concentration are considerable in plant infection; and the reporter gene is also a good strategy for early infection selection, such as neomycin phosphotransferase gene (NPTⅡ), green fluorescent protein (GFP), red fluorescent protein (DsRed), and β-glucuronidase (GUS) genes [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. In addition, the H subunit of magnesium chelatase magnesium chelatase (CHLH), a key enzyme involved in chlorophyll biosynthesis, is chosen as a good reporter gene, in that its silencing phenotype was clearly observed through chimeric phenotypes with yellow/white leaves [33][34][35][36].…”