Plant model systems for chromosome segregation and chromosome recombination study

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Svitlana Sytnyk
added 2 research items
The parameters of wood density (WD), bark density (BD) and tree crown characteristics are not only important for estimation of the aboveground biomass, but they also serve as indicators for the timber quality. This study had two objectives: Black locust ( Robinia pseudoacacia L.) – an introduced species; Scots pine ( Pinus sylvestris L.) – an aboriginal species. Black locust and Scots pine from the Steppe zone in Ukraine were compared in their WD and BD, and in the morphological parameters of their tree crowns. There were determined basic WD and BD for differently aged individuals of Black locust and Scots pine. Generally, a higher WD was found for Black locust trees. The average Black locust WD was 518 kg m ⁻³ , ranging from 375 kg m ⁻³ to 612 kg m ⁻³ ; with the average BD – 294 kg m ⁻³ , ranging from 214 kg m ⁻³ to 421 kg m ⁻³ . The average Scots pine WD was 414 kg m ⁻³ , ranging from 254 to 491 kg m ⁻³ ; with average BD – 317 kg m ⁻³ , ranging from 178 to 433 kg m ⁻³ . The dependences between WD, BD and biometric tree parameters were identified by correlation analysis. The crown diameter for Black locust and Scots pine was described with fixed prediction models. We proposed particular equations for relationships between foliage biomass and branch biomass, derived from the crown volume of the investigated species.
За допомогою методів термогравіметрії – термогравіметричної кривої (ТГ), диференціальної термогравіметричної кривої (ДТГ), або кривої інтенсивності зміни маси досліджуваного зразка, досліджено термічну деструкцію деревини і кори головної лісотвірної породи штучних лісових насаджень Північного Степу України – робінії несправжньоакації (Robinia pseudoacacia L.). Термічний аналіз зразків деревини і кори здійснено в окиснювальній (повітря) атмосфері. Встановлено стадії термічного розкладання деревинної речовини і кори в умовах програмованого нагріву до 600 оС зі швидкістю 10 оС/хв (ТГ/ДТГ/ДТА), їх температурні інтервали, втрату маси, інтенсивність втрати маси та теплові ефекти. На основі аналізу величин енергії активації на окремих стадіях термічного розкладання, залежності енергії активації від ступеня конверсії деревини і кори, а також із порівняння втрати маси на відповідних стадіях термодеструкції, теплових ефектів, залишкової маси і інших параметрів ТГ/ДТГ, охарактеризовано деревину і кору робінії. Деревина робінії характеризується значнішою термостабільністю, ніж кора. Запропоновано математичні моделі для оцінювання залежності втрати маси від температури деструкції складників надземної фітомаси (кори, деревини) досліджуваного деревного виду.
Olga Zimina
added 3 research items
There is plenty of evidence for genome instability in somatic tissues due to mitotic disorders. This short review focuses on the phenomena of chromosome number reduction in somatic plant cells referred to in the literature by different names as somatic reduction, somatic segregation, meiosis-like reduction, prophase grouping and assortment mitosis.
Precise chromosome segregation is vital for speciation and hybrid formation. The aim of this work was to study the chromosomes behavior and inheritance of maternal and paternal genomes in Arabidopsis regenerants obtained from in vitro cultured cells on the medium with para-fluorophenyalanine (PFPA). The Arabidopsis thaliana model hybrid between Columbia and Landsberg erecta ecotypes was developed, which chromosomes were easy to distinguish using the 12 SSLP selected markers. Also, the influence of PFPA on callus formation and regeneration of plants was analyzed. 20 regenerated plants cultured with PFPA were derived, three of which were shown to loss the heterozygosity in six loci by DNA markers analysis. Different models are certainly required to understand how and when the mechanisms leading to proper chromosome segregation are established in species and hybrids.
The goal of the work was, using the database «The Arabidopsis Information Resource» TAIR, to select 12 SSLP-markers distributed along the Arabidopsis chromosomes and chromosome arms, to optimize the conditions of amplification of each fragment and for simultaneous amplification of several fragments. For identification of A. thaliana ecotypes and their hybrid, the SSLP sequences were used. These DNA markers are highly polymorphic in Arabidopsis and easy to use. Using this database, the primers were selected for 12 SSLP-markers distributed along all chromosomes and their arms. A. thaliana ecotypes Columbia and Landsberg erecta were used. The experiments revealed that two-stage PCR using two annealing temperatures of primers in each cycle allows efficient amplification of all the fragments considered. The conditions for carrying out two multiplex PCR, each of which allows the two fragments were amplified and a single multiplex PCR allowing three markers for amplification were defined. The developed system of DNA markers can be used to study the behavior and inheritance of each chromosome of maternal and paternal genomes of Arabidopsis hybrids and enables quick and efficient genetic analysis.