The Genome Sequence of the North-European Cucumber (Cucumis sativus L.) Unravels Evolutionary Adaptation Mechanisms in Plants

Cucumber (Cucumis sativus L.), a widely cultivated crop, has originated from Eastern Himalayas and secondary domestication regions includes highly divergent climate conditions e.g. temperate and subtropical. We wanted to uncover adaptive genome differences between the cucumber cultivars and what sort of evolutionary molecular mechanisms regulate genetic adaptation of plants to different ecosystems and organism biodiversity. Here we present the draft genome sequence of the Cucumis sativus genome of the North-European Borszczagowski cultivar (line B10) and comparative genomics studies with the known genomes of: C. sativus (Chinese cultivar – Chinese Long (line 9930)), Arabidopsis thaliana, Populus trichocarpa and Oryza sativa. Cucumber genomes show extensive chromosomal rearrangements, distinct differences in quantity of the particular genes (e.g. involved in photosynthesis, respiration, sugar metabolism, chlorophyll degradation, regulation of gene expression, photooxidative stress tolerance, higher non-optimal temperatures tolerance and ammonium ion assimilation) as well as in distributions of abscisic acid-, dehydration- and ethylene-responsive cis-regulatory elements (CREs) in promoters of orthologous group of genes, which lead to the specific adaptation features. Abscisic acid treatment of non-acclimated Arabidopsis and C. sativus seedlings induced moderate freezing tolerance in Arabidopsis but not in C. sativus. This experiment together with analysis of abscisic acid-specific CRE distributions give a clue why C. sativus is much more susceptible to moderate freezing stresses than A. thaliana. Comparative analysis of all the five genomes showed that, each species and/or cultivars has a specific profile of CRE content in promoters of orthologous genes. Our results constitute the substantial and original resource for the basic and applied research on environmental adaptations of plants, which could facilitate creation of new crops with improved growth and yield in divergent conditions

Biological methods of weeds control: possibilities and practice

Aby zdecydować o biologicznym zwalczaniu jakiegoś chwastu należy wpierw wykonać wiele, często wieloletnich, kosztownych badań zarówno samego chwastu jak i jego wrogów. Ponieważ jednak przy tej metodzie unikamy stosowania syntetycznych herbicydów i chronimy środowisko, metoda ta w niektórych krajach zyskuje na popularności tymbardziej, że są już w świecie dość liczne przykłady udanych zabiegów znacznego obniżenia liczebności i znaczenia danego chwastu. Te przykłady sukcesu dotyczą w dużej mierze chwastów zawleczonych z obcych regionów. Obejmują one rośliny zielne, krzewy i drzewa, rosnące zarówno wśród roślin uprawnych jak i w innych zespołach roślinnych. Te udane przykłady zwalczania chwastów metodą biologiczną opisywane są z rejonów spoza Europy. W Europie na razie jest to metoda reklamowana, omawiana i są liczne badania wstępne z tego zakresu.The biological control simply aims to use naturally occuring enemies to help reduce the invasive plant’s impact on agriculture and environment. Some herbivores and pathogens can be effective biocontrol agents for weeds. Not all weeds are suitable for biological control. The selection of appropriate target weeds is a serious consideration. It can take up to twenty scientist years to reach a successful conclusion. Environmental considerations may restrict future biological control practice because of increased concerns about possible damage to non target native or even agricultural plants. However, biological control has been successfully used against a wide variety of weed types, from a broad taxonomic spectrum, from annual herbs to trees. The diversity of weeds that have been controlled biologically Is a clear indication of a great utility of the method, even it is not possible to predict the outcome of particular projects. Developing a biological control project requires a substantial investment. Considerably host-specifity testing is done prior to the release of biological control agents to ensure they will not pose a threat to non target species such as native and agricultural plants In Europe no classical biological control agent has been released against an invasive weed, but many studies are carried out and future expectations lead in this direction