2 Стендский исследовательский центр Института сельскохозяйственных ресурсов и экономики, Латвийский сельскохозяйственный университет, Стенде, ЛатвияИзучено генетическое разнообразие растений-регенерантов пшеницы (Triticum aestivum L.), которые созданы методом культуры пыльников из гибридов, используемых в селекции этой культуры в Латвии. Метод проточной цитометрии применяли для определения плоидности каждого зеленого растения-регенеранта. В свою очередь, универсальным iPBS (inter primer binding sites) методом, основанном на анализе характерных последовательностей ретротранспозонов, определяли генетическое разнообразие этих растений. Анализу подвергали потомство 13 гибридов различного происхождения. В листьях большинства растений были миксоплоидные клетки. Семена дали только растения, имеющие клетки с плоидностью 2n = 6x. Большинство фертильных растений содержало в листьях более чем 40 % гексаплоидных (6x) клеток. Доля гексаплоидных клеток и их распределение по плоидности зависели от генотипа материнского гибридного растения. Доля спонтанной диплоидизации также зависела от генотипа растения. В описываемом эксперименте колхицинирование не оказало достоверного влияния на выход фертильных растений. У одного гибридного растения обнаружена новая доминантная аллель, отсутствующая у обоих родите лей, что указывает на возможное передвижение ретро транс позонов. Генетическое разнообразие растений-регенерантов, созданных методом культуры пыльников, вызвано как расщеплением родительских аллелей, так и сомаклональной изменчивостью.Ключевые слова: культура пыльников; ДГ-линии; селекция пшеницы; плоидность; проточная цитометрия; iPBS.The study of genetic diversity of wheat (Triticum aesti vum L.) plants-regenerants produced by anther culture method from hybrids involved in the Latvian wheat breeding programme was performed. Flow cytometry was used to test ploidy of 3 × 10 3 cells of each green plantregenerant, and universal retrotransposon based iPBS (inter primer binding sites) method were used to establish genetic diversity of plants-regenerants. Progenies of 13 genetically distant hybrids were involved in the study. Most of plants-regenerants have leaves with mixoploid cells. Seeds were formed only by plants-regenerants that had cells with (2n = 6x) ploidy. Majority of fertile plantsregenerants have more than 40 % of hexaploid (6x) cells. The percentage of 6x cells in plants-regenerants and diversity in cell ploidy demonstrated association with mother plant (hybrid) genotype. Percent of spontaneous diplodization was also genotype-dependent. In this experiment colchicine treatment had no significant influence on outcome of fertile plants-regenerants. New dominant allele in a hybrid plant was found in comparison with both parents what indicated possible retrotransposon moving. Genetic diversity of the plants-regenerants obtained in anther culture is a combination of parent's allele segregation and somaclonal variation.

Our goal was to improve the method of obtaining double haploids (DH) by anther culture from Latvian breeding material for several agriculturally important cereals in Latvia: barley, spring and winter wheat. Hybrids from Latvian breeders were initial material. It was found that copper (2.5 mg/l) added to barley anther pre-treatment media and to both barley (C3) and wheat (liquid AMC) induction media, resulted in a higher percentage of green plants-regenerants. In general, the winter wheat hybrids exhibited lower embryogenesis than spring wheat hybrids. Obtaining a large number of DH lines from barley and wheat hybrids with unknown androgenesis response can be organized in two stages: first - selection from breeding initial material hybrids responsive in anther culture, which enables production of green plants-regenerants, and second - production of DH lines in a large scale from selected hybrids.

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Molecular markers based on retrotransposons possibility of integration into genomes of many organisms are commonly used for genetic analysis of different species. The aim of this study was to test possibility of use those markers in perch and detect genetic diversity of populations of two lakes of the Latgale region of Latvia: Cirišs and Sventes. The distance between the lakes is nearly 60 km, they belong to the same Daugava river basin but are different from ecological point of view. Forty two blood samples of <em>Perca fluviatilis </em>were collected altogether. Extracted DNA was analyzed using inter-PBS amplification technique with specifically selected retrotransposon-based primers and agarose gel electrophoresis. Data of genetic diversity of lakes were calculated by POPGENE and NTSYS software. In total, 127 loci were found in two populations, 81 of them were polymorphic. In spite of rather small distance between lakes Cirišs and Sventes, several differences in genetic variation of populations of two lakes were found. For example, the number of polymorphic loci in samples from Sventes lake was 61, but from Cirišs lake only 47. A unique allele was found in Lake Sventes. Genetic similarity and distance between populations of lakes Cirišs and Sventes was 0.9288 and 0.0739 respectively. Results proved that molecular markers based on retrotransposons PBS regions can be very useful to test genetic diversity of fish populations.

According to the Global Strategy for Plant Conservation, 75% of endangered species should be preserved in ex situ collections till 2020. The genus Liparis has a lot of recognised taxons, but only one species, Liparis loeselii (L.) Rich., grows in Europe. L. loeselii is a rare and endangered orchid species occurring in Europe. In Latvia L. loeselii is classified as the third category of endangered and protected species. To develop the best conservation strategy, the knowledge concerning the genetic differences of protected plants in a particular area is crucial. For this purpose, the genetic diversity of L. loeselii populations from different Latvian habitats was tested. The inter-retrotransposon amplified polymorphism method (iPBS) was used for population genetic diversity evolution. In total, 54 accessions from nine habitats were collected and analysed. L. loeselii leaves have a high content of phenols that reduce the quality of extracted DNA. It was found that the percentage of polymorph loci varied among the populations of L. loeselii growing in different habitats; some of the populations were genetically homogeneous. The genetic diversity levels of L. loeselii populations are related with the population age and the growing conditions.