Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


maize

CYTOLOGICAL MECHANISMS OF THE CELLS NUMBER REDUCTION IN EMBRYO SACS OF THE TOBACCO MUTANT

Megaspore- and megagametophytogenesis in tobacco mutant with reduced cells number in embryo sacs were studied. It is established, that the mutation causes a disturbance of one pair of homologous chromosomes conjugation in meiosis. Consequently alongside with the haploid (24-chromosomal) spores aneuploid (23-chromosomal) spores forms which are developed into abnormal embryo sacs. At cenocyte stage of megagametophytes development falling out of 1-2 mitoses and/or their abnormal course were observed, as well as abnormalities in embryo sacs polarization.

Optimization of the technique for maize protoplast isolation and their nativity after electroporation

We optimizes the composition and concentration of the enzymes, the time for enzymatic treatment and the volume of the enzyme mixture. We also optimized the concentration osmotic of agent, the centrifugation mode, and fi lter pore size for protoplasts isolating from epidermal cells of maize roots (Zea mays L.) of the Brown Marker (BM) line. It was found that 150 minutes is the optimal time for 150 mg root tissue maceration.

Induction of Direct Organogenesis in the Culture of Mature Embryo in Maize

Regeneration of plants in vitro through direct organogenesis allows the avoidance of somaclonal variation. The aim of our study was the induction of direct organogenesis in the culture of mature embryo in maize lines created at Saratov State University: ATTM (bm, wx, y), ATTM (bm, y), ATTM (bm, g, V-type CMS), AT-3 (4n). These lines are characterized by genetic predisposition to parthenogenesis. The mature embryos isolated from sterile grains were used as a primary explant.

Hormonal Regulation of Morphogenesis in the Culture of Mature Embryo in the Maize Parthenogenetic Line АТТМ (bm, wx, y)

The article presents the results of the search for the optimal hormonal composition of the nutrient medium for the induction of direct organogenesis in the culture of mature embryos of the maize homozygous line ATTM (bm, wx, y). The mature embryos isolated from kernels were used as the primary explant. The 11 media variants were tested for induction of direct organogenesis: MS without hormones (control) and with phytohormones in different concentrations and combinations.