Efekat niske početne pH vrednosti hranljive podloge na rast bele topole in vitro

The effect of low initial medium pH on shoot and root development of five white poplar (Populus alba L.) genotypes was tested. The shoot height, fresh mass of shoots per jar, dry mass of shoots per jar, number of roots, as well as the length of the longest root were measured and final pH of the media determined, after 35 days of culture in vitro. Three initial pH values of the medium were tested: 3.0, 4.0 and 5.5 as control. Agar solidification at pH 3.0 was not achieved after sterilization in autoclave, but it was successful after sterilizing in a microwave oven. The obtained results indicate that the tested genotypes are able to significantly influence the changes of media pH during culture. The effect of differences among the examined media was significant for biomass accumulation and final media pH. Generally, significantly higher values of fresh and dry shoot mass, shoot height and the longest root length were recorded on a medium with initial pH 3.0 then on a standard medium with pH 5.5.The implications of the obtained results for the improvement of in vitro propagation of white poplars are discussed.U istraživanju je testiran efekat niske početne pH vrednosti hranljive podloge na razvoj izbojaka i korena pet genotipova bele domaće topole (Populus alba L.). Nakon 35 dana kultivacije u kulturi in vitro mereni su visina izbojaka, sveža masa izbojaka po teglici, suva masa izbojaka po teglici, broj korenova, dužina najdužeg korena i određena je konačna pH vrednost hranljive podloge. Tri početne vrednosti pH medijuma - 3,0, 4,0 i 5,5- ispitane su kao standardna pH vrednost medijuma (kontrola). Problemi sa očvršćavanjem podloge kod podloga sa niskom početnom pH nakon sterilizacije, prevaziđene su sterilizacijom podloge u mikrotalasnoj pećnici. Dobijeni rezultati ukazuju na to da ispitivani genotipovi imaju mogućnost da utiču na promenu pH podloge tokom uzgoja u kulturi in vitro. Većina ispitivanih genotipova bele topole ostvarila je značajno bolji rast i razvoj izbojka i korenovog sistema, kao i akumulaciju biomase na podlozi sa početnom vrednošću pH. U radu se diskutuje o implikacijama dobijenih rezultata za poboljšanje in vitro razmnožavanja bele topole

Mycorrhizal status of an ozone-sensitive poplar clone treated with the antiozonant ethylene diurea

The antiozonant ethylene diurea is proven to prevent growth reductions in forest trees induced by ozone. The community of mycorrhizal fungi could be useful indicator of environmental stress. In this study, response of mycorrhizal fungi and fine roots to a 4-year exposure to ambient ozone and treatment with antiozonant was investigated in ozone-sensitive poplar clone under field conditions. The community of ectomycorrhizal fungi and root length colonization with ectomycorrhizal, arbuscular mycorrhizal fungi, and root endophytic fungi was analyzed in antiozonant-treated poplar plants and in poplar plants irrigated with water. In general, plants protected by antiozonant showed higher total number of fine roots, number of ectomycorrhizal types, Shannon–Weaver diversity index, and Species richness index compared to the plants treated with water. The ectomycorrhizal community shifted from contact exploration type in the trees irrigated with water to short-distance exploration type in ethylene diurea-treated trees. Ozone protectant may beneficially affect the belowground community of mycorrhizal fungi colonizing roots of ozone-sensitive poplar clone

In vitro Evaluation of Copper Tolerance and Accumulation in Populus nigra

Phytoextraction is an efficient and cheap way to extract copper from soils in riparian zones. In this work five genotypes of the endangered tree species Populus nigra L. were tested for their copper tolerance and accumulation in vitro when cultivated on media with three Cu concentrations: 10(-3), 10(-4) and 10(-7) M ( buffered with citric acid/Na-citrate buffer, pH 3 before sterilization). After five-weeks cultivation of rooted shoots, the highest increases in morphological and biomass parameters were observed at 10(-7) M Cu2+. As the medium with 10(-3) M Cu2+ exhibited a toxic effect, the effect of 10(-4) M Cu2+ and pH 3 was used for further genotype evaluation. According to the measured morphological and parameters of photosynthetic pigment contents, the best performance was achieved by the genotype Populus nigra cl. DN3. The highest copper accumulation on the same medium was achieved by genotype Populus nigra cl. BN5. The obtained data point to the considerable potential of the applied method in the evaluation of Populus nigra genotypes for use in projects of copper phytoextraction

Dense poplar plantations as the raw material for the production of energy

The higher heating value of wood and bark was determined for several poplar (Populus spp) clones. The study included the juvenile one year old plants of the following clones: P.×euramericana cl. ostia, P. nigra cl.53/86, P. deltoides cl. PE 19/66, P.×euramericana cl. I-214, P. deltoides cl. S6-7 and P.×euramericana cv. robusta. By using FVI which takes into account ash content, wood bulk density, and moisture content, it was determined that poplar wood can be a significant energy raw material, primarily thanks to its short rotation cycle and a very high wood volume increment. Significant differences were determined in the values of wood basic density which affect the higher heating value of the study poplar clones, and consequently the yield (weight) of biomass produced per unit area of dense plantations. This is reflected also on the estimated amount of energy that can be produced by the combustion of biomass of the whole one year old plants

Relationship among eastern cottonwood genotypes according to early rooting traits

The relationship between twelve genotypes of eastern cottonwood (Populus deltoides Bartr.) was analyzed according to sixteen early rooting traits and cutting survival. Principal component analysis (PCA) and cluster analysis were used on data that were standardized by common and by one alternative way of standardization. Alternative way of standardization (standardization with within-genotype standard deviation instead of standard deviation of genotypes’ means) was used in order to emphasize the contribution of genotype to the effect of differences among genotypes on total variation. After bought ways the first principal component had high correlation with the most of rooting traits and cutting survival, while the second was mainly related to the traits of root formation on the basal cut of cutting (wound roots). Three difficult-to-root genotypes (S6-7, S1-3, 129/81) were distinctly grouped against other examined genotypes, by bought principal component and cluster analysis. There was a slight difference in grouping of easy-to-root genotypes (B-229 and PE19/66) among examined ways of standardization

Mycorrhizal Fungal Community of Poplars Growing on Pyrite Tailings Contaminated Site near the River Timok

Background and Purpose: Mycorrhizal fungi are of high importance for functioning of forest ecosystems and they could be used as indicators of environmental stress. The aim of this research was to analyze ectomycorrhizal community structure and to determine root colonization rate with ectomycorrhizal, arbuscular mycorrhizal and endophytic fungi of poplars growing on pyrite tailings contaminated site near the river Timok (Eastern Serbia). Materials and Methods: Identification of ectomycorrhizal types was performed by combining morphological and anatomical characterization of ectomycorrhizae with molecular identification approach, based on sequencing of the nuclear ITS rRNA region. Also, colonization of poplar roots with ectomycorrhizal, arbuscular mycorrhizal and dark septated endophytic fungi were analysed with intersection method. Results and Conclusions: Physico-chemical analyses of soil from studied site showed unfavourable water properties of soil, relatively low pH and high content of heavy metals (copper and zinc). In investigated samples only four different ectomycorrhizal fungi were found. To the species level were identified Thelephora terrestris and Tomentella ellisi, while two types remained unidentified. Type Thelephora terrestris made up 89% of all ectomycorrhizal roots on studied site. Consequently total values of Species richness index and Shannon-Weaver diversity index were 0.80 and 0.43, respectively. No structures of arbuscular mycorrhizal fungi were recorded. Unfavourable environmental conditions prevailing on investigated site caused decrease of ectomycorrhizal types diversity. Our findings point out that mycorrhyzal fungal community could be used as an appropriate indicator of environmental changes

Promene pH vrednosti podloge prilikom mikropropagacije bele topole

In this study, changes in the pH of the nutrient medium were investigated after 35 days of cultivation of four white poplar genotypes (Populus alba L.). Four initial pH values of the substrate were tested: 3.0, 4.0, 5.5 and 7.0 buffered sodium citrate buffer, as well as a standard medium for micropropagation with pH 5.5 without the addition of citric acid (control) The medium was sterilized in a microwave oven. The results of the variance analysis indicate that the final pH of the medium after cultivation, as well as the difference between the final and the initial pH of the medium, was significantly influence of initial pH, as well as the interaction of the genotype × medium, differences between genotypes in their reaction to the washed pH medium. On media with low initial pH was recorded positive, while the medium pH 7.0 was recorded negative change pH after cultivation. The results of the study indicate that changes in the pH of the medium during cultivation lead to a pH that is assumed to be optimal for their cultivation under in vitro conditions (cca. pH 5.5). The possibility of applying the obtained results in the improvement of the white poplar cultivation in vitro and the assessment of genotypes in melioration and phytooremediation projects is discussed.U ovom istraživanju je ispitivana promena pH vrednosti hranljive podloge nakon 35 dana kultivacije četiri genotipa bele topole (Populus alba L.). Ispitane su četiri početne pH vrednosti podloga: 3,0, 4,0, 5,5 i 7,0 puferisane natrijum citratnim puferom, kao i standardna podloga za umnožavanje sa pH 5,5 bez dodavanja limunske kiseline (kontrola). Sterilizacija podloge je izvršena u mikrotalasnoj pećnici. Rezultati analize varijanse ukazuju da su konačni pH podloge nakon kultivacije, kao i razlika između krajnje i početne pH podloge veoma značajno zavisili od početne pH. Takođe je i interakcija genotip × podloga pokazala statistički znacajan uticaj na pomenuta svojstva. Na podlogama sa niskom početnom pH je zabeležena pozitivna, dok je na podlozi pH 7,0 zabeležena negativna promena pH tokom kultivacije. Rezultati istraživanja ukazuju da promene pH podloge tokom kultivacije vode ka vrednosti pH 5,5 za koju pretpostavljamo da bi bila optimalna za njihov uzgoj u uslovima in vitro (oko pH 5,5). Diskutovana je mogućnost primene dobijenih rezulata u unapređenju uzgoja bele topole in vitro i ocene genotipova u projektima melioracije i fitoremedijacije