scholarly journals The monoploid chromosome complement of reconstructed ancestral genomes in a phylogeny

Author(s):  
Qiaoji Xu ◽  
Xiaomeng Zhang ◽  
Yue Zhang ◽  
Chunfang Zheng ◽  
James H. Leebens-Mack ◽  
...  

Using RACCROCHE, a method for reconstructing gene content and order of ancestral chromosomes from a phylogeny of extant genomes represented by the gene orders on their chromosomes, we study the evolution of three orders of woody plants. The method retrieves the monoploid complement of each Ancestor in a phylogeny, consisting a complete set of distinct chromosomes, despite some of the extant genomes being recently or historically polyploidized. The three orders are the Sapindales, the Fagales and the Malvales. All of these are independently estimated to have ancestral monoploid number [Formula: see text].

2020 ◽  
Author(s):  
Fiona J Whelan ◽  
Rebecca J Hall ◽  
James O McInerney

A pangenome is the complete set of genes (core and accessory) present in a phylogenetic clade. We hypothesize that a pangenome’s accessory gene content is structured and maintained by selection. To test this hypothesis, we interrogated the genomes of 40 Pseudomonas genomes for statistically significant coincident (i.e. co-occurring/avoiding) gene patterns. We found that 86.7% of common accessory genes are involved in ≥1 coincident relationship. Further, genes that co-occur and/or avoid each other - but are not vertically or horizontally co-inherited - are more likely to share Gene Ontology categories, are more likely to be simultaneously transcribed, and are more likely to produce interacting proteins, than would be expected by chance. These results are not due to coincident genes being adjacent to one another on the chromosome. Together, these findings suggest that the accessory genome is structured into interacting sets of genes co-selected to function together within a given strain. Given the simi larity of the Pseudomonas pangenome with open pangenomes of other prokaryotic species, we speculate that these results are generalizable.


1989 ◽  
Vol 7 (2) ◽  
pp. 77-78
Author(s):  
Tom Ness
Keyword(s):  

2014 ◽  
Vol 26 (3-4) ◽  
pp. 42-61
Author(s):  
O. G. Lucyshyn ◽  
I. K. Teslenko

The recent ecological situation of Kyiv megalopolis has a special specific of environment technogenic pollution as a chemical features and content of polluting phytotoxicants. During 2007–2012, our observation revealed what the most dangerous factors which have harm impact on the street woody plants are the huge concentration of phytotoxic elements (Na+, Cl-, Pb2+, Cd2+). Nowadays, the technogenic impact on the megalopolyisis surrounding comes to the dangerous, even, catastrophic level. The main reason of total and chloral necrose of leaves, the summer defoliation of crown and major tree's death is the over pollution of the soil and plant's phytomass by phytotoxic elements, the concentration of which by standards evaluation and by trees reactions are critical and exists at the level of adaptation possibility and survival. The main sources of Pb2+ and Cd2+ ions are transport outcomes (> 90 % of total technogenic pollution). The increasing of Pb2+ and Cd2+ in the soil is depended from intensivity of transport outcomes, using of ethylated petrol, and location of trees along roads as well as from the trees species. Continuously increasing of number of cars at the city streets is accompanying with similar increasing of ions concentration. Thus, in the soil around root system of street woody plants, depending from their location along roads, the concentration of Pb2+ (moving form) is between 41,7 (I. Kudri str.) and 102,6 mg\kg of soil (Nauki avenue). It exceeds the maximum permissible concentration (MPC), which is 20,8–51,3 mg\kg of soil. Next, for Norway maple (Acer platanoides) the concentration of Pb2+ in the soil varies from 41,7 to 80,5 mg / kg of soil in the area of the root system and it is around 20,8–40,2 MPC. In the leaves of this tree it is 7,83–13,5 mg / kg of dry mass (MPC is 15,8–27,0). For the horse chestnut (Aedculus hippocastanum) at the Nauka avenue, the concentration of plumbum in the root is 13,4 mg / kg (MPC is 26,8), in the cortex – 17,7 mg / kg (MPC is 35,4), in leaves – 8,21 mg / kg (MPC is 16,4), which by the normative evaluation are the critical concentrations. The source of Na+ and Cl-, which is a new factor for Kyiv megalopolis, is irregular load of high concentrations of industrial salt NaCl into the environment, as a way against black ice in winter time, where the Na+ ions ( mobile form) is in the high concentrations in leaves (0,76 % for Norway maple (Acer platanoides) on the I. Kudri str., 1,28 % – small-leaved linden (Tilia cordata) at the 40-richya Zhovtnya ave, 2,0 % – horse chestnut (Aedculus hippocastanum) at the Nauki ave), those are exceeded the concentration of the element comparing to the control test object, respectively, in 10,6, 12,8 and 5,0 times. Na+ ions are an aggressive phytotoxins and the main factor of leaves necrose of tree crown (within 70–100 % necrosis leaves in the crown). Degradation and total reduction of the specific weight of plants in the megalopolis environment are decrease the cleaning role of the street tree plants, which are the main alive filters for soil and air cleaning, as well as the main bioaccumulators and detoxicants of harm substances of anthropogenic pollution. Species adaptive specificity is revealed at the bioaccumulation level and the selective locality of phytotoxic elements (Na+, Cl-, Pb2+, Cd2+, agile form) in technourbanhabitats-pic conditions, there dominated bioaccumulation and localization of Na+ ions by trees assimilative system is caused the adaptive orientation of endogenic and intraspecific variability of phytoindicative morphophysiologic features of plants functional condition under the stressing factors. This also is defined the sensitivity of small-leaved linden (Tilia cordata Mill.), norway maple (Acer platanoides L.) and horse chestnut (Aesculus hippocastanum L.) to the big concentration of potassium as the most danger one for the plant survival. The biggest accumulation of Na+ ions at the roots of Lombardy poplar (Populus pyramidalis Roz.), Bolle's poplar (Populus bolleana Lauche) and sugar maple (Acer saccharinum L.) is lead to a higher resistance of their assimilation system. At the technourbohabitate-pic conditions, the level of realization of ontogenetic and phylogenetic adaptive capacity of the sensitive species of trees is harmfully low (21,3–44,3 %). It is at the level of survival/death of plants. The street Lombardy poplar, Bolle's poplar and sugar maple, despite of more higher level of their adaptation (68,4–87,7 %), still also can't fully adapt to the critical levels of technogenic pollution of megalopolis environment. 


2017 ◽  
Vol 7 (4) ◽  
pp. 51-55
Author(s):  
S. A. Abiev ◽  
S. A. Aipeisova ◽  
N. A. Utarbaeva

<p>The purpose of our work is to assess the health state of woody plants growing in different habitats of the city of Aktobe. We have studied the health state of arboreal and shrubby plants growing in various urban habitats; the survey was conducted during 2016-2017 by route-visual method. We performed the analysis of species diversity, abundance and density in urban area. The assessment of health state of the trees was made according to V.A. Alekseev. From your data and literature review we established that such species as Ulmus pinnato-ramosa, Acer negundo, Populus tremula, Populus nigra, and Syringa vulgaris have strong winter resistnce in the territory of Aktobe; we registered that only their apex buds and emds of the shoots were frozen in severe winters. The medium-resistant speices include Ulmus laevis and Acer platonoides. They are less plastic and suffer from late spring and early autumn frosts. The Amorpha fruticosa, Vitis vinifera, and Parthenocissus guinguefolia could be considered as the non-resistant species, since they usually freeze up to the snow cover line. The analysis of the vital state made it possible to assess the resistance to urban conditions of the majority of trees and shrubs registered in urban habitats of Aktobe. According to the preliminary data, the origin of the plant and its winter resistance are of main importance when introducing new species to urban area.</p>


2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 818-818
Author(s):  
K. R. Wall ◽  
C. R. Kerth ◽  
T. R. Whitney ◽  
S. B. Smith ◽  
J. L. Glasscock ◽  
...  

2019 ◽  
pp. 55-70
Author(s):  
И.Р. Грибуст

Введение. Лесомелиоративное обустройство территорий малолесных регионов коренным образом преобразует ранее пустынные пространства. Позитивные изменения влажностнотеплового, почвенного, гидрологического режимов, обогащение аборигенной дендрофлоры новыми видами влечет за собой также и трансформацию животного мира, в том числе населения насекомых. Энтомосообщества формируются за счет представителей степной группы, обитателей естественных ценозов, а также группы лесных насекомых, в числе которых виды, являющиеся опасными вредителями и их энтомофаги. Цель работы анализ изменения разнообразия насекомыхэнтомофагов в насаждениях засушливой зоны различных параметров и состояния. Объекты исследований насекомыеэнтомофаги, обитающие в энтомокомплексах защитных насаждениях различного дендрологического состава ФНЦ агроэкологии РАН на территории Волгоградской области (кадастр. 34:34:000000:122 34:08:000000:6). Материалы и методика. Сбор материала проводили в насаждениях различного хозяйственного значения. Объектами исследования являлись полезные насекомые. Отбор проб проводили посредством окашивания крон энтомологическим сачком, визуальным осмотром модельных ветвей и ручным сбором хищников и паразитированных видов филлофагов с последующим выведением имаго в лабораторных условиях. Результаты и обсуждение. В сообществе полезных насекомых защитных лесных насаждений сухостепной зоны зафиксирован 221 вид энтомофагов, относящихся к 7 отрядам и 32 семействам. Различия экологических условий, ассортимент древесных растений в каждой из посадок, характер и интенсивность негативного внешнего влияния определяют особенности фаунистического населения, в т. ч. энтомофагов. Оценка распределения количественного обилия паразитов и хищников показала, что в лесных полосах хищников в среднем в три раза больше паразитических насекомых. Отчетливо прослеживаются вариации изменения разнообразия энтомофагов в насаждениях разного класса жизнеспособности. Конструктивные особенности, флористическая обедненность и сформировавшийся микроклимат существенно ограничивает жизнедеятельность энтомофагов в малорядных (23 ряда) насаждениях, численность которых здесь снижается в среднем в 2,5 раза по сравнению с многорядными посадками. В вертикальном градиенте посадок по мощности накопления биотического потенциала полезных насекомых выделяется травянистый ярус, наличие которого в лесополосе обусловливает увеличение числа особей энтомофагов в сообществе в 1,32,7 раза. Наименьшую роль в накоплении полезной группы насекомых играет наличие развитого подлеска. Заключение. Наличие в насаждениях энтомофильных древесных растений и развитого травостоя важнейшие экологические факторы для накопления биотического потенциала энтомофагов. Максимальный эффект обеспечивает совокупное влияние определяющих экологоструктурных элементов в многорядных посадках. Introduction. Forest reclamation area developmentpoor regions is radically transforms the previously desolate space. Positive changes in moistureheat, soil, hydrological regimes, enrichment of native dendroflora with new species also entails the transformation of the animal world, including the insect population. Entomologiste formed by the representatives of the steppe group of the inhabitants of the natural coenoses, and the group of forest insects, including species that are dangerous pests and their entomophages. The purpose of the analysis of changes in the diversity of insect entomophages in the plantations of the arid zone of different parameters and conditions. The objects of research insectsentomophages living in entomocomplexes protective plantation of different dendrological composition of the Federal scientific center for Agroecology wounds on the territory of the Volgograd region (the cadaster number is 34:34:000000:122 34:08:000000:6). Materials and methods. Collection of material was carried out in plantations of various economic importance. The objects of study were useful insects. Samples were collected by hilling crowns entomological net, by visual inspection of the model branches and handcollection of predators and parasitism species of phyllophagous with subsequent excretion of adults in the laboratory. Results and discussion. 221 species of entomophages belonging to 7 groups and 32 families were recorded in the community of useful insects of protective forest plantations of the dry steppe zone. Differences in environmental conditions, the range of woody plants in each of the plantings, the nature and intensity of the negative external influence determine the characteristics of the faunal population, including entomophages The estimation of distribution of quantitative abundance of parasites and predators showed that in forest bands of predators on average three times more parasitic insects. Variations in the diversity of entomophages in plantings of different classes of viability are clearly observed. Design features, floristic depletion and formed microclimate significantly limits the life activity of entomophages in smallrow (23 rows) plantations, the number of which is reduced by an average of 2.5 times compared to multirow planting. In the vertical gradient of plantings on the power of accumulation of biotic potential of useful insects, a grassy tier is allocated, the presence of which in the forest belt causes an increase in the number of entomophages in the community by 1.32.7 times. The least role in the accumulation of a useful group of insects is played by the presence of developed undergrowth. Conclusion. The presence of entomophilic woody plants and developed herbage in the plantations are the most important environmental factors for the accumulation of the entomophage biotic potential. The maximum effect provides a cumulative effect of determining ecological and structural elements in multirow landings.


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