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


кукуруза

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.

Оптимизация методики получения протопластов кукурузы и их нативность после электропорации

Приведены результаты оптимизации методики изоляции
протопластов из эпидермальных клеток корней кукурузы (Zea mays L.)
линии Коричневый маркер (KM), в ходе которой были проведены
скрининговые исследования по подбору состава и концентрации
ферментов, соотношения времени ферментативной обработки
растительного материала и объема ферментной смеси, концентрации
осмотического агента, режима центрифугирования и размера пор фильтра,
применяемого при очистке суспензии протопластов. Выявлено, что

Combination ability of corn lines and genetic control of morphometric parameters

The article presents the results of studying the combination ability of new dihaploid maize lines created by diploidization of haploid plants obtained using a haploinducer line. The experiment involved simple hybrids (30 combinations) obtained according to the complete diallel scheme of 6 homozygous lines. The eff ects of GCA and variance of SCA lines, as well as the components of genetic variance in terms of the main morphometric parameters of the plant (stem length, ear height, panicle length, stem diameter, plant leaf surface area) were revealed.

Polyembryony Phenomenon in Apomictic Maize Line in vivo and in vitro

The article is focused on studying of cytoembryological preconditions of polyembryony in the not pollinated ovary of the apomictic maize line АТ-1 under in vitro and in vivo conditions. For an assessment of a nutrient medium role in polyembryony induction a relative analysis of the embryo sacs in cultivated in vitro and native plants ovaries has been lead. Dynamics of formation in them an apomictic twin proem- bryo is traced.

Introduction to Culture in vitro of Corn Parthenogenetic Lines

Many modern selection technologies are based on the use of haploid plants as a starting material. The spontaneous frequency of haploid development is very low (0.01–0.1%). In this regard, the creation of plant forms with increased frequency of parthenogenesis is important. The collection of corn lines with an increased frequency of haploid plants in the progeny was created at the Department of Genetics of the Saratov State University. High costs are required for maintain of a plant collections in the field.

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.