Variation among progenies of diploid plants regenerated from haploid, microspore‐derived cell‐suspension protoplasts of rice (Oryza sativa L.)

Abstract

Progenies of 110 diploid RQ plants regenerated from haploid protoplasts derived from microspore callus cell suspension culture of rice (cv. Miara) were evaluated for 6 traits, along with control lines, in a replicated field trial. Complementary post-harvest observations were carded out for four panicle or grain characters. A wide range of vadation was observed for all traits under study among the protoclonal lines. The mean ofthe protoclonal population was significantly different from that ofthe control for most traits and 64.5% ofthe lines differed from the control for at least one field-evaluated trait. A unidirectional shift towards later-maturing, taller, and lower-tillering lines was observed. Of all the lines, 39% were taller than the control by at least 10 cm, 31 % had flowering delayed by at least 5 days, and 13% exhibited significantly longer panicles (P = 0.05). As to the agronomical value of the lines, the vadation resulted in a global negative drift although favourable variations were found in a few lines. All but two lines were homogeneous, suggesting that most variations existed in a homozygous form in the RQ plants. Ro lines grown from seeds of 17 R, protoclonal lines stably inherited the changes and did not segregate, thereby confirming that variations are fixed.

Fertility and growth in the field of Lolium perenne and Festuca rubra plants regenerated from suspension cultured cells and protoplasts

“…Fifty-two per cent of the L. perenne somaclones and 30% of the F. rubra somaclones showed later inflorescence emergence than the latest seed-grown genotype. This drift to later inflorescence emergence of regenerated plants was also reported for progenies of regenerated barley (Hordeum vulgare L.), spring wheat (Triticum aestivum L.) and rice (Oryza sativa L.) (Baillie et al 1992, Qureshi et al 1992, Mezencev et al 1995. The lower seed yield of regenerated L. perenne was associated with fewer seeds recovered after harvesting and cleaning and not with lower average seed dry weight.…”

“…In contrast, F. rubra had an progenies of regenerated barley (Hordeum vulgare L.), spring inferior agronomic performance. This differential response may wheat {Triticum aestivum L.) and rice {Oryza sativa L.) (Baillie be related to differences in genome complexity between the et al 1992, Qureshi et al 1992, Mezencev et al 1995. The lower octoploid F. rubra compared with the autotetraploid L. perenne seed yield of regenerated L. perenne was associated with fewer (Jackson andDale 1988, Karp 1995).…”

“…1992, Qureshi eta!. 1992, Mezencev et al 1995. RAPD analysis revealed somaclonal variation in plants regenerated from both L. perenne and F. rubra.…”

Characterization of Some Chromosomal Aberrations in Regenerated Rice Plants (Oryza sativa)

“…The total somaclonal variation rate in past studies was reported to be between 25 and 50% for rice suspension cultures including hexaploid plants (2n = 6x = 72) (Mezencev et al, 1995), which is more than the changes in the embryo culture plants in our study. Despite the fact that the lack of an efficient regeneration method in indica, rice still poses a major problem for genetic manipulation (Toki, 1997) and the regeneration rate of indica varieties has been reported to be less than that in japonica cultivars (Saharan et al, 2004).…”

“…Ploidy levels were detected between n and 6n with rate of 50% for cell suspension and 25% for the plants derived from embryo culture (Mezencev et al, 1995). Other chromosomal variations like deficiencies took place on various chromosomes of rice spontaneously or by pollens irradiating (Wang and Iwata, 1995).…”