Efficient plant regeneration from hypocotyl protoplasts of broccoli (Brassica oleracea L. ssp. italica Plenck)

Abstract

We have assessed the capacity of cultured protoplasts from two tissue sources of several commercially-grown broccoli cultivars to regenerate plants. A procedure that employs hypocotyl protoplasts and a culture medium with a high NAA:2,4-D auxin ratio was developed. The procedure permits highly efficient formation of colonies that regenerate shoots at frequencies of 8-17% with two of the four cultivars tested. The time required for the development of plants from protoplasts was 8-11 weeks. No mtDNA rearrangements were observed among any of 17 analysed regenerants. Double-stranded RNAs were detected in mitochondrial DNA (mtDNA) preparations of some, but not all, regenerants of one of the cultivars.

Plant regeneration from petal protoplast culture ofPetunia hybrida

“…Thus, the combined and relatively high concentrations of auxins were needed to achieve optimal petal protoplast culture, suggesting that the auxins are more limiting than cytokinin for the petal protoplast proliferation. This result is consistent with earlier findings that the combined auxins were relatively effective for cell proliferation in hypocotyl protoplast cultures of Fagopyrum esculentum and Brassica oleracea (Adachi et al 1989;Kao et al 1990) and in mesophyll protoplast cultures of Felicia bergeriana and Petunia hybrida (Malaure et al 1990;Oh & Kim 1988).…”

Genetic correlation of the orf224/atp6 gene region with Polima CMS in Brassica somatic hybrids

“…This demonstrated that the pol cytoplasm confers male sterility in broccoli, and, since one such plant possessed broccoli chloroplasts, their resuits also showed that the male sterility determinant resided on the mitochondrial genome. B. napus × B. oleracea hybrids produced by either embryo rescue following sexual crosses [ 11 ] or somatic hybridization [4] are male fertile, and male sterility was not observed in over 100 broccoli plants regenerated using the procedure employed here for the somatic hybrids [5]. Moreover, plants regenerated by our procedure from protoplast fusion products that possess a pure 2,3…”