In vitro cultures of zygotes and small embryos carry a lot of potential for studying plant embryogenesis and are also highly relevant for plant biotechnology. Several years ago we established an in vitro ovule culture technique for barley that allows the regeneration of plants from zygotes (Holm et al., 1995, Sex. Plant. Reprod. 8:49-59). This culture system proved to be highly effective and indications for genotype independency was obtained. To further sustain this we recently investigated the ovule culture response in the cultivar Golden Promise and three cultivars known for low tissue culture ability in immature embryo culture i.e. Femina, Salome and Corniche. Barley spikes were emasculated and hand pollinated 3 days after emasculation. In barley, fertilization takes place one hour after pollination and ovules with fertilized egg cells could therefore be isolated one hour after pollination. Ovules were grown for 3 weeks on a culture medium where after embryos could be isolated and transferred to regeneration medium. An average of 1.2 green plantlets per ovule could be regenerated from 50 % of the isolated ovules. No genotypic differences were found on embryo induction and regeneration frequencies. Fifty plants of each cultivar were randomly chosen and grown to maturity in the greenhouse and all developed to phenotypically normal and fertile plants. We have used the system to develop an Agrobacterium mediated transformation procedure for barley ovules, which is largely genotype independent (Holme et al., 2006, Plant Cell Rep 25: 1325-1335; Holme et al., 2008, Plant Cell Rep 27: 1833-1 840).
Molecular Aspects of Plant Development 2010. Programme and Abstracts, 2010