Detection of Somaclonal Variation in Micropropagated and Acclimatized Plantlets of Oryza sativa MRQ 74 from Stem Explants

Abstract

In plant tissue culture system, the excessive supply of plant growth hormones may inhibit further growth and development of the regenerants and sometimes it may induce somaclonal variation. In this study, the optimum concentration of plant growth hormones for in vitro regeneration of Oryza sativa L. cv. MRQ 74 was identified and subsequently the occurrence of somaclonal variation of regenerated plantlets was determined through cytological analysis of in vivo and in vitro grown plantlets. MS media supplemented with 0.1 mg L-1 BAP in combination with 0.1 mg L-1 NAA was found to be the optimum concentration for shoots and roots induction of Oryza sativa L. cv. MRQ 74. Plantlets derived from MS media supplemented with 0.5 mg L-1 2,4-D showed higher survival rate than that of MS media supplemented with 0.1 mg L-1 BAP in combination with 0.1 mg L-1 NAA. The plant height, number of leaf, leaf length and number of seeds per stalk of acclimatized plants were significantly lower (p<0.05) as compared with plants grown in vivo. Cytological analysis of in vivo and in vitro grown Oryza sativa L. cv. MRQ 74 revealed that the presence of 2,4-D in the culture media had significantly decreased the mitotic index (MI) and increased the ploidy level of the cell nuclei. The findings of the present study would be useful for plant breeders and biotechnologist since somaclonal variation provides a useful source of genetic variation for crop productivity and quality improvement.

Attenuation of morpho-anatomical disorders of micropropagated plantlets of Crinum malabaricum Lekhak and Yadav using seismo-mechanical stimulation

“…Harvested fresh weight (gm) − Inoculated fresh weight (gm) Inoculated fresh weight (gm) carotenoids) were analyzed following Saini et al (2001). The leaves (200 mg) were dissected from the control, seismic stress treated, and acclimatized plantlets, and the pigments were extracted in dark at room temperature with mild agitation.…”

“…The morphological deformities of in vitro-regenerated plantlets such as necrosis, fasciation, somaclonal variations, hyperhydricity, translucency, reduced leaf expansion, pale and fragile shoot, and root systems were discussed in several species (Hazarika 2006;Chiruvella et al 2014;Saleh et al 2019). The physiological and anatomical aberrations of in vitro-regenerated plantlets include nonfunctional stomata, reduced chlorophyll content and poor photosynthetic efficiency, low epicuticular wax formation, deficient vascular and mechanical tissues, low metabolic activity, etc.…”