Intergeneric somatic hybrids of rice [Oryza sativa L. (+) Porteresia coarctata (Roxb.) Tateoka].
Somatic hybrid plants were obtained following the electrofusion of rice (Oryza sativa L. cv 'Taipei 309', 2n = 2x = 24) cell suspension-derived protoplasts with non-dividing leaf protoplasts of Porteresia coarctata (2n = 4x = 48), a saline-tolerant wild species. Fusion-treated protoplasts were plated on the surface of cellulose nitrate filter membranes, overlaying Lolium multiflorum nurse cells. The nurse cells were embedded in KPR medium containing 0.5 mg l(-1) 2,4-dichlorophenoxyacetic acid and semi-solidified with SeaPlaque agarose. Putative somatic hybrid cell colonies were selected on the basis of their growth, whereby faster growing colonies were transferred preferentially to MS-based medium with 2.0 mg l(-1) kinetin, 0.5 mg l(-1)α-naphthaleneacetic acid, 30 g l(-1) sucrose and 4.0 g l(-1) SeaKem agarose to induce shoot regeneration. One hundred and nineteen regenerated plants were micropropagated clonally on MS-based medium containing 2.0 mg l(-1) 6-benzylaminopurine, 50 g l(-1) sucrose and 4.0 g l(-1) SeaKem agarose, prior to DNA extraction of plant samples. Putative somatic hybrids were initially identified by RAPD analysis, and 8 plant lines were selected for further investigation by flow cytometric ploidy determination and cytology. Plants of one line had an allohexaploid chromosome complement (2n = 6x = 72) and, following examination of its vegetative clones by GISH, were confirmed as somatic hybrids containing full chromosome complements of both O. sativa and P. coarctata.
Plant Science Division, School of Biological Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK, GB.
N B
NB
Jelodar
N W
NW
Blackhall
T P
TP
Hartman
D S
DS
Brar
G
G
Khush
M R
MR
Davey
E C
EC
Cocking
J B
JB
Power