The article presents the results of a study of the content of pigments in the leaves of black poplar growing along the auto roads in Biysk. The increase in technogenic pollution contributes to the change in the amount and ratio of basic and additional pigments. Compared with the control, a significant decrease in the content of chlorophyll a and the ratio of chlorophyll a/b, a significant increase in the content of chlorophyll b and carotenoids were revealed.

СОМАКЛОНАЛЬНАЯ ИЗМЕНЧИВОСТЬ IN VITRO КАК ИСТОЧНИК СОЗДАНИЯ ИСХОДНОГО МАТЕРИАЛА ДЛЯ СЕЛЕКЦИИ МЯГКОЙ ПШЕНИЦЫ¹Алтайский научно-исследовательский институт сельского хозяйства, Барнаул, Россия, E-mail: aniizis@ab.ru ²Алтайский государственный университет, Барнаул, Россия E-mail: hlebova61@mail.ru The genotypes with a wide spectrum of variable features which could be of great interest for producing new forms were revealed. It is noted that the display of traits affected not only a genotype, but changes occurring at the cellular level during in vitro cultivation. Significant differences among somaclones derived from a callus were stated.

Stevia rebaudiana (Bertoni) Hemsl. belongs to Asteraceae family and is of great importance for pharmaceutical and food industries. Stevioside obtained from the leaves of this plant is regarded as a valuable natural sweetener. Low seed fertility is one of the most important problems in stevia production. It multiplies almost exclusively in a vegetative way. Plant tissue culture is an efficient method for mass propagation of S. rebaudiana. We studied the effect of various concentrations of auxins on rooting stevia shoot cuttings under in vitro conditions. We found that adding 0.6-1.0 mg l-1 IBA or 0.2 mg l-1 IAA to the В5 medium is effective forrooting the shoot fragments of this species. The regenerants were adapted to ex vitro conditions for 3 weeks on a hydroponic setup filled with a solution of mineral salts according to the quarter-strength Murashige and Skoog (MS) basal medium modified by the content of KH2PO4 and NH4NO3. Using a triple concentration of KH2PO4 (510 mg l-1) during the first week of adaptation and a fullconcentration of NH4NO3 (1650 mg l-1) over the next 2 weeks ensures 100% acclimatization of stevia regenerants to ex vitro conditions. The replacement of agar in the nutrient medium with a perlite-vermiculite mixture in the ratio of 1 : 3 stimulated the transition of regenerants to the photomyxotrophic type of nutrition. The use of a porous substrate provided a decrease in humidity inside the culture vessels, which led to forming both leaves with well-functioning stomata and a branched root system with root hairs. The stevia regenerants propagated in vitro on a porous substrate did not require special conditions for the ex vitro acclimatization. The yield of surviving plants in the greenhouse was 100%.

The Development of Stress-resistant Stock of Spring Bread Wheat by in Vitro Cell Selection Изучено влияние различных концентраций хлорида натрия на процессы индукции каллуса и регенерации растений в культуре незрелых зародышей пяти сортов мягкой яровой пшеницы. Отбор клеточных линий in vitro, пролиферирующих на солевой среде и сохраняющих регенерационные способности, следует проводить при концентрации хлорида натрия до 1,2-1,3 %.

We performed a bioassay of aqueous extracts from the bottom sediments of the Chumysh River near the settlement of Talmenka (the Altai Territory of Russia) using the Allium test. The presence of toxic components that caused a decrease in the mitotic activity of onion root meristem cells was revealed. The frequency of pathological mitoses, significantly exceeding the background value (on average, 16.3 times), indicates the presence of factors with total mutagenic activity in the samples. We found violations of chromosome divergences (emissions beyond the spindle, lagging, running off and premature chromosome divergence), abnormalities of the mitotic apparatus (multipolar, asymmetric, monocentric mitosis, polyploidy), bridges (single and multiple). The prevalence of spindle pathologies suggests chemical contamination of the bottom sediments. Stress factors present in bottom sediments activate adaptive mechanisms of the test-object cells, aimed at maintaining their viability and reliability of the transmission of genetic information to the next cellular generations. Such adaptation mechanisms include the formation of micronuclei and cell polyploidization.