The biomass productivity of the energy willow Salix viminalis as a short-rotation woody crop depends on organ structure and functions that are under the control of genome size. Colchicine treatment of axillary buds resulted in a set of autotetraploid S. viminalis var. Energo genotypes (polyploid Energo [PP-E]; 2n = 4x = 76) with variation in the green pixel-based shoot surface area. In cases where increased shoot biomass was observed, it was primarily derived from larger leaf size and wider stem diameter. Autotetraploidy slowed primary growth and increased shoot diameter (a parameter of secondary growth). The duplicated genome size enlarged bark and wood layers in twigs sampled in the field. The PP-E plants developed wider leaves with thicker midrib and enlarged palisade parenchyma cells. Autotetraploid leaves contained significantly increased amounts of active gibberellins, cytokinins, salicylic acid, and jasmonate compared with diploid individuals. Greater net photosynthetic CO2 uptake was detected in leaves of PP-E plants with increased chlorophyll and carotenoid contents. Improved photosynthetic functions in tetraploids were also shown by more efficient electron transport rates of photosystems I and II. Autotetraploidization increased the biomass of the root system of PP-E plants relative to diploids. Sections of tetraploid roots showed thickening with enlarged cortex cells. Elevated amounts of indole acetic acid, active cytokinins, active gibberellin, and salicylic acid were detected in the root tips of these plants. The presented variation in traits of tetraploid willow genotypes provides a basis to use autopolyploidization as a chromosome engineering technique to alter the organ development of energy plants in order to improve biomass productivity.

• MeSH
• biomasa MeSH
• chlorofyl metabolismus   MeSH
• chromozomy rostlin genetika   MeSH
• diploidie MeSH
• dřevo genetika   fyziologie   MeSH
• duplikace chromozomů MeSH
• fenotyp MeSH
• fotosyntéza genetika   fyziologie   MeSH
• genom rostlinný genetika   MeSH
• genotyp MeSH
• karotenoidy metabolismus   MeSH
• konfokální mikroskopie MeSH
• kořeny rostlin genetika   fyziologie   MeSH
• kůra rostlin genetika   fyziologie   MeSH
• listy rostlin genetika   fyziologie   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• Salix genetika   fyziologie   MeSH
• stonky rostlin genetika   fyziologie   MeSH
• tetraploidie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH
• karotenoidy MeSH
• regulátory růstu rostlin MeSH

Trees with hollows are key features sustaining biodiversity in wooded landscapes. They host rich assemblages of often highly specialised organisms. Hollow trees, however, have become rare and localised in Europe. Many of the associated biota is thus declining or endangered. The challenge of its conservation, therefore, is to safeguard the presence of hollow trees in sufficient numbers. Populations of numerous species associated with tree hollows and dead wood are often found in habitats that were formed by formerly common traditional silvicultural practices such as coppicing, pollarding or pasture. Although it has been occasionally mentioned that such practices increase the formation of hollows and the availability of often sun-exposed dead wood, their effect has never been quantified. Our study examined the hollow incidence in pollard and non-pollard (unmanaged) willows and the effect of pollarding on incremental growth rate by tree ring analysis. The probability of hollow occurrence was substantially higher in pollard than in non-pollard trees. Young pollards, especially, form hollows much more often than non-pollards; for instance, in trees of 50 cm DBH, the probability of hollow ocurrence was ∼0.75 in pollards, but only ∼0.3 in non-pollards. No difference in growth rate was found. Pollarding thus leads to the rapid formation of tree hollows, a habitat usually associated with old trees. It is therefore potentially a very important tool in the restoration of saproxylic habitats and conservation of hollow-dependent fauna. If applied along e.g. roads and watercourses, pollarding could also be used to increase landscape connectivity for saproxylic organisms. In reserves where pollarding was formerly practiced, its restoration would be necessary to prevent loss of saproxylic biodiversity. Our results point to the importance of active management measures for maintaining availability, and spatial and temporal continuity of deadwood microhabitats.

• MeSH
• biodiverzita * MeSH
• dřevo fyziologie   MeSH
• lesnictví metody   MeSH
• pravděpodobnost MeSH
• Salix anatomie a histologie   růst a vývoj   fyziologie   MeSH
• stromy anatomie a histologie   růst a vývoj   fyziologie   MeSH
• zachování přírodních zdrojů * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH