Organogenesis and Plantlet Formation from Organ‐ and Seedling‐Derived Calli of Rice (Oryza sativa)

Abstract

Callus was induced in different somatic organs of Oryza sativa L. Specific minimum 2,4‐dichlorophenoxyacetic acid (2,4‐D) concentrations in the medium were necessary for the induction of callus from different organs while high levels of 2,4‐D (6–10 mg/l) induced callus formation in each organ tested. The optimum 2,4‐D concentration for callus induction and growth for root‐derived calli was 2 mg/l and for leaf‐derived 6 mg/l. Root and shoot organogenesis were induced in both root‐ and leaf‐derived calli by sub‐culturing to a medium lacking 2,4‐D. Root organogenesis occurred at a higher frequency than shoot organogenesis. Shoot organogenesis rarely occurred in calli without differentiated roots. Increased age of callus cultures almost completely inhibited shoot development. The addition of the cytokinin 6‐γ,γ‐dimethylallyl‐amino purine partially restored the potential for shoot organogenesis. Whole plants were easily recovered from the calli and grown to maturity with some plants exhibiting phenotypic abnormalities.

High frequency plant regeneration from embryogenic callus of a popular indica rice (Oryza sativa L.)

“…Development of simple method to regenerate highly fertile plants in a relatively short period of time is desirable to achieve genetic modification in crop plants like rice. It was demonstrated that 1-5 mm segments of leaf base of 3-4 days old rice seedlings were most suitable for the induction of callus as compared to any other seedling derived organ (Henke et al, 1978). In the present study using 8 different concentrations (0.5-4.5 mg L -1 ) of 2,4-D, only 2.5 mg L -1 showed maximum callus induction and mean fresh weight.…”

“…Despite a large number of reports on rice tissue culture, there is significant genotype-dependence, and in vitro regeneration of indica rice is still a challenging task (Kumria et al, 2000). There are several successful reports on regeneration from explants such as leaf blade (Yan and Zhao, 1982), root tips (Sticklen, 1991), leaf sheath/leaf sections (Wernicke and Milkovits, 1984), immature panicles (Shu and Wei, 1980), mature seed embryos (Ramesh and Gupta, 2006), immature embryo (Koetje et al, 1989), coleoptile (Oinam and Kothari, 1995), anthers (Genovesi and Magill, 1982), stem nodes (Furuhashi and Yatazuva, 1964), seedling derived mesocotyl segments (Mascarenhas et al, 1975), leaf segments (Henke et al, 1978) and leaf bases (Ramesh et al, 2009). …”

A review of somaclonal variation in plantain (<i>Musa</i> spp): mechanisms and applications

“…Ngezahayo1 et al (2007) studied the nature of somaclonal variation at the nucleotide sequence level in the cultivar rice Nipponbare using RAPD and ISSR markers and by pairwise sequence analysis. Earlier reports on somaclonal variation in rice include those of Nishi et al (1968) and Henke et al (1978), all from rice callus. Variations were observed in number of tillers per plant, number of fertile tillers per plant, length of panicle, frequency of fertile seeds, plant stature and length of flag leaf.…”

Effects of growth regulators on callus cell growth, plant regeneration, and somaclonal variation of smooth bromegrass (Bromus inermis Leyss.)

“…Callus grown on media A, B, and F showed the same response, but significantly more callus growth than on media C, D, and E . (Lo et al, 1980), and rice (Henke et al ., 1978), but not in smooth bromegrass and crested wheatgrass (Lo et al ., 1980) . In this study, the less amount of kinetin (0 .2 mg 1-') promoted shoot formation in smooth bromegrass callus culture in some instances .…”