Plant regeneration from tissue cultures of Pokkali rice is promoted by optimizing callus to medium volume ratio and by a medium-conditioning factor produced by embryogenic callus

Abstract

The frequency of plant regeneration from seed-derived Pokkali rice callus has been substantially increased. Four conclusions were drawn from the study: (1)Nonembryogenic callus consisting of elongated, highly-vacuolated cells did not produce regenerated plants. Embryogenic callus consisting of small, non-vacuolated cells produced somatic embryos and regenerated plants. (2)The numbers of plants could be markedly increased by optimizing a medium for embryogenic callus production and a second medium for plant regeneration from embryogenie callus. (3) The optimization of callus to medium volume ratio of 6.5 mg embryogenic callus per 1.0 ml of medium significantly increase plant production on regeneration medium. (4) A further significant .increase was obtained by using regeneration medium previously conditioned for one or two weeks by optimal amounts of embryogenic callus. At present, the callus derived from a single seed in six months could theoretically be used in the seventh month to produce 127 500 plants.

A short communication on in vitro techniques on a few crops including Oryzae sativa, Zea mays, Triticum aestivum and Shorgumbicolor cultivated in Madhav University Campus, Pindwara, Sirohi District of Rajasthan, India

“…Raghava et al [15] eported Cytokinin mediated long-term, high frequency plant regeneration in rice tissue culture. Cytokinin has its own impact for cell differentiation during Tissue culture techniques [16] . The present study also has a good result of morphogenesis in some crops taken for experiment.…”

“…The endosperm contains mainly starch granules and protein bodies. The callus induction and subsequent plantlet regeneration from various explants of rice (Oryza sativa) proved a result of healthier candidate [16] . Similarly, On the other hand, Yan et al .…”

“…Genotype, media, and cultural conditions of anther donor plant are analyzed and discussed as possible causes for the failure of callus induction in anther culture ]19 ,20] . Furthermore, Rao et al [16] found a relationship between the origin of embryo-derived callus and the minor elements copper, cobalt and molybdenum in the medium. Besides, Callus formation from immature embryos usually took a week longer than that of mature embryo.…”

An Improved Method for Shoot Regeneration from Calli of Indica Rice (Basmati)

“…Successful plant regeneration from rice callus has been reported by several researchers (Raghava Ram and Nabors, 1985;Abe and Futsuhara, 1989;Hartke and Lorz, 1989;Ozawa and Komamine, 1989;Tsukahara and Hirosawa, 1992). However, there are several limitations that need to be overcome.…”

The effects of 2ip and 2,4-D on rice calli differentiation

“…To genetically transform paddy rice, the classical approach is to select embryogenic calli, which are then continuously cultured in suitable media to maintain their embryogenic potential [5,7,9,21]. Earlier reports demonstrated that a number of chemical and physical factors presented in the culturing surroundings, such as the ratio of NH: and NO;, amino acids and hormones, osmotic pressure, even the initial volume and density of calli have great influence on the proliferation of embryonic calli and initiationof shoot regeneration [3,12,13,15,17,201. Since the frequency of producing transgenic plants relies on the dedifferentiation and redifferentiation of cultured cell, organ and tissue, a way to maximize cereal cell regeneration is badly needed for it is such an important crop plant world-wide.…”