Variation in juvenile traits of natural black poplar (Populus nigra L.) clones in Turkey

Natural black poplar (Populus nigra L.) clones sampled from river courses were tested in the arid southeast region of Turkey, using a randomized complete block field design with four replications. Clones were laid out in row plots of eight ramets each. Height and apical dominance were assessed at age one year; diameter, survival, bole straightness and branchiness were measured at age two years. Clones differed significantly in survival, growth and quality traits. The results showed that promising clones exist in natural populations. Two commercial clones out of four did not grow as fast as the top new selection clones. For bole straightness, three commercial clones had significantly lower grading scores than the top best 14 clones. Principal components analysis indicated that growth, apical dominance and branching are the most important traits distinguishing black poplar clones. Diameter had a moderate correlation (0.34) with bole straightness. Relationships between geographic variables (elevation, latitude and longitude) with growth and stem quality traits were weak. Considerable genetic variation was observed among clones for all the traits. Genetic differences among the clones accounted for 27% (survival, bole straightness) to 39% (height) of the total variance. Broad-sense individual heritability ranged from 0.27 (survival) to 0.37 (apical dominance). Clonal mean heritabilities were higher than individual heritabilities and ranged from 0.60 (survival) to 0.82 (diameter), implying considerable gain could be realized via selective improvement methods.     

Performance of wheat as intercrop under poplar (Populus deltoides Bartr.) plantations in Punjab (India)

In an agrisilvicultural system having poplar (Populus deltoides, clone G-3) as a tree component and wheat crop as an intercrop, wheat yield was studied under five age classes of poplar and compared to wheat yield under pure cropping. A substantial reduction in wheat yield (23.3%) under three-year-old poplar plantation was observed. Maximum MAI (GBH, 20 cm) was recorded in a three-year-old poplar planting. Pruning after the third year permitted some recovery in yield. The reduction in wheat yield was significantly correlated with MAI (GBH) of poplar and occurred even under one-and-two-year-old poplar plantings.     

Morphometry of leaf and shoot variables to assess aboveground biomass structure and carbon sequestration by different varieties of white mulberry(Morus alba L.)

Mulberry is economically important and can also play a pivotal role in mitigating greenhouse gases.Leaf and shoot traits were measured for Morus alba var.Kanmas...     

Morphogenetic responses of Populus alba L. under salt stress

The morphogenetic responses to salt stress of Tunisian Populus alba clones were studied in order to promote their plantation in damaged saline areas.One year-old plants of three P.alba clones(MA-104,MA-195 and OG)were subjected to progressive salt stress by irrigation during two consecutive years.The plants were grown in a nursery,inside plastic receptacles containing sandy soil and were irrigated with tap water(control)or 3–6 g/l NaCl solution.During this study,leaf epinasty,elongation rate,vigor,internode length,plant architecture,and number of buds were evaluated.Test clone response was highly dependent on the applied treatment and degree of accommodation.The most pronounced alterations were induced under 6g/l of NaCl treatment including leaf epinasty,leaf elongation rate delay,vigor decrease,internode length shortening,and morphogenetic modifications.These responses were less noticeable in the MA-104 clone with respect to the two other clones.The salt effect induced a delay in the leaf elongation rate on the MA-195 and OG clones leading to an early leaf maturity.The vigour and internode length of the MA-104 clone was less affected than the other clones.The OG clone was the most salt-sensitive thus,it developed shorter branches and more buds number than MA-195 and MA-104.The effect of long-term salt stress was to induce early flowering of the P.alba clones which suggests that mechanism of salt accommodation could be developed.     

The complete chloroplast genomic landscape and phylogenetic analyses of Populus alba L.

Populus alba is a foundation species in evolutionary and ecological studies in the northern hemisphere.In this study, the chloroplast genome and gene map of P.alba were constructed. The P. alba chloroplast genome is156,505 bp in length comprising a large single-copy region, two inverted repeat regions and a small single-copy region. The genome contains 131 genes, including 86 protein-coding genes(77 PCG species), eight ribosomal RNA genes(four r RNA species) and 37 transfer RNA genes(30 t RNA species). Phylogenetic analysis indicates that all Populus chloroplast genome sequences are clustered together and divided into three large branches.Among reported Populus chloroplast genomes, the leuce section formed monophyletic, indicating that all Populus spp. have a common maternal ancestor. P. rotundifolia and P. tremula are closely related and are sisters to P.davidiana. P. alba is closely related to P. adenopoda.Population genetic research in ecology and evolution may be easily developed through chloroplast genomes as they are conserved. This research will benefit future studies related to Populus, one of the world's most ecologically and economically important genera.     

Assessing bacterial communities in the rhizosphere of 8-year-old genetically modified poplar(Populus spp.)

Microbe communities in rhizosphere ecosystems are important for plant health but there is limited knowledge of them in the rhizospheres of genetically modified(GM) plants, especial for tree species. We used the amplitude sequencing method to analyze the V4 regions of the 16 S r RNA gene to identify changes in bacterial diversity and community structure in two GM lines(D520 and D521), one non-genetically modified(nonGM) line and in uncultivated soil. After chimera filtering,468.133 sequences in the domain Bacteria remained. There were ten dominant taxonomic groups(with [1 % of all sequences) across the samples. 241 of 551 genera(representing a ratio of 97.33 %) were common to all samples.A Venn diagram showed that 1.926 operational taxonomic units(OTUs) were shared by all samples. We found a specific change, a reduction in Chloroflexi, in the microorganisms in the rhizosphere soil planted with poplars. Taken together, the results showed few statistical differences in the bacterial diversity and community structure between the GM line and non-GM line, this suggests that there was no or very limited impact of this genetic modification on the bacterial communities in the rhizosphere.     

Performance of wheat varieties under poplar (Populus deltoides Bartr.) plantations in Punjab (India)

Three varieties of wheat, viz., PBW-222, HD-2329 and PBW-34, were studied for grain yield potential under six-year-old poplar plantations. The order of yield reduction found was: PBW-34 (57.1%)>PBW-222 (19.4%)>HD-2329 (15.3%). The reduction in wheat yield was found to be significant under poplar plantations as compared to crops grown in open condition. Research needs to maintain the increased wheat production by evolving suitable ideotypes for an agrisilviculture system have been suggested.     

Effects of two iron sources on iron and cadmium allocation in poplar (Populus alba) plants exposed to cadmium

Effects of 10 microM cadmium (supplied as Cd nitrate) on the utilization and allocation of iron (Fe) were investigated in poplar (Populus alba L.) plants grown in nutrient solution with Fe(III)-EDTA or Fe(III)-citrate as the Fe source. The effects of Cd were also compared with those of Fe deprivation. The accumulation of Fe in roots was 10-fold higher in plants grown with Fe-citrate than with Fe-EDTA. Cadmium decreased leaf chlorophyll concentrations and photosynthetic rates, and these decreases were more marked in plants grown with Fe-citrate than with Fe-EDTA. In both Fe treatments, addition of Cd caused large increases in root and shoot apoplasmic and non-apoplasmic Cd contents and increases in root Fe content; however, Cd decreased shoot Fe content, especially in plants grown with Fe-citrate. New leaves of plants grown with Fe-citrate had small cellular (non-apoplasmic) Fe pools, whereas these pools were large in new leaves of plants grown with Fe-EDTA. Non-apoplasmic Cd pools in new leaves were smaller in plants grown with Fe-citrate than with Fe-EDTA, indicating that inactivation of non-apoplasmic Cd pools is facilitated more by Fe-EDTA than by Fe-citrate. In the presence of Cd, Fe-EDTA was also superior to Fe-citrate in maintaining an adequate Fe supply to poplar shoots. Differences in plant responses to Fe-EDTA and Fe-citrate may reflect differences in long-distance transport of Fe rather than in acquisition of Fe by roots.     

Intercropping ginger and turmeric with poplar (Populus deltoides ‘G-3’ Marsh.)

Performance of two rhizomatous crops i.e. ginger (Zingiber officinale Rosc.) and turmeric (Curcuma longa L.) was investigated under rainfed conditions in pure stands and as intercrops with 5-year-old poplars planted at three spacings viz., 5×5 m, 5×4 m and 5×3 m. The average illumination below the canopies was 53, 46 and 38% of incident radiation, respectively. Both crops performed better as intercrops than as pure stands. Survival was inversely correlated to light intensity. Plant height, tillers per plant and leaves per plant in ginger and leaf length and leaf breadth besides plant height in turmeric were significantly enhanced when intercropped. The rhizome length, rhizome breadth, yield per plant and yield per ha in ginger exceeded under poplars but showed a drastic reduction under the closest poplar spacing. In turmeric, the trend for the first two characters was the same, whereas yield per plant as well as yeild per ha were slightly greater in the open than under 5×3 m spacing. Dry matter content varied significantly with spacing. For quality parameters, only oil content in ginger and oleoresin in turmeric showed significant differences. The cultivation of turmeric proved more remunerative than ginger.Among the poplar spacings, 5×4 m for ginger and 5×5 m for turmeric were delineated as the best spacings.     

论桑树资源经济价值和生态功能

文章对于桑树资源开发利用的历史和现状及开发利用实践知识,知识经济的创新,中国桑产业新思路的拓展进行了综合阐述,并对其经济价值和生态效能进行论证。桑树经济价值不仅仅是桑叶养蚕,桑树的果、叶、枝、皮皆为良药,桑树的叶、皮、根含有多种氨基酸。桑果除含多种氨基酸外,还富含多种营养物质和维生素以及矿质元素等。桑树在防沙、治沙、节水、保土等生态功能也优于其他树种,它是北方众多省区生态环境建设中的首选树种之一。     

ELISA Quantitation and GC-MS identification of abscisic acid in stigma, ovary and pedicel of pollinated poplar flowers (Populus nigra L.)

A method of fractionation, quantitation and identification of abscisic acid (ABA) in poplar flowers is presented in the context of intra- and interspecific pollination studies in Populus nigra x P. nigra and P. nigra x P. deltoides, respectively. Poplar flowers were dissected into stigma, ovary and pedicel. Abscisic acid concentrations were measured at receptivity and 5 days after pollination in each part of the flower. Abscisic acid was fractionated by reverse-phase HPLC followed by an enzyme-linked immunosorbent assay (ELISA) with anti-ABA polyclonal antibody and GC-MS identification of the immunoreactive ABA fractions. Samples were fractionated and ABA was identified by the presence of a cross-reactive metabolite of ABA in the extracts. The interspecific cross (P. nigra x P. deltoides) had a high concentration of ABA in the pedicel, where abscission occurred, whereas in the intraspecific cross, ABA concentration in the pedicel was low. The results are discussed with reference to the control ABA exerts on the abscission of poplar flowers after interspecific incompatible pollinations.     

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen (Populus tremula L.) in Bulgaria

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.     

The occurrence of Phellinus tremulae (Bond.) Bond. and Borisov as a primary parasite in Populus tremula L.

Phellinus tremulae was inoculated on Populus tremula. It spread in the sapwood and inner wood of a living tree without other organisms being present. Plating experiments with wood meal from different parts of a sound tree showed that there were very few, if any, propagules of micro organisms in the sound wood, neither were there any organisms found in front of the decay of P. tremulae at the top of the decay column. These results support the theory that P. tremulae is a primary parasite in aspen. Decay fungi grown on fresh and autoclaved wood of aspen had very different growth rates. Most of the fungi tested grew best on autoclaved sapvvood. The difference in growth rate on fresh and autoclaved heartwood was lcss significant, suggesting that there is a barrier in the living wood which is destroyed by autoclaving. P. tremulae was thc only fungus that grew best on fresh inner wood.     

对新疆杨扦插幼苗施用植物喷施灵的初报

本文对新疆杨扦插幼苗施用植物喷施灵进行了初步探讨，结果表明：①在20天内能促进新疆杨扦插幼苗高生长。②20天内不能显著提高叶绿素含量水平。③20天内显著降低了多酚氧化物酶活性水平。④20天内提高了过氧化物酶活性水平。     

Lateral bud outgrowth on decapitated shoots of low-pruned mulberry (Morus alba L.)

After decapitation, lateral shoot growth of mulberry coppice (Morus alba L. cv. Shin-ichinose) from 10-year-old stumps had an extremely acrotonic form compared with that of intact one-year-old stems of trees during the spring. When one dominant shoot from each stump was decapitated, only a few upper lateral buds grew out and elongated. Defoliation of the decapitated shoots resulted in an increase in the number of shoots sprouting and a decrease in the rate of elongation of the laterals. Further enhancement of laterals on decapitated dominant shoots resulted from the removal of competing intact coppice shoots from the stumps. 1-Naphthaleneacetic acid (NAA) applied as a spray reduced the number of lateral buds sprouting from both defoliated, decapitated erect shoots and intact horizontally trained shoots. The results suggest that management of mulberry coppice could increase the supply of leaves for commercial silk production.     

山杨接毛白杨实用技术

从接穗采集贮藏、砧木的选择、嫁接时间、嫁接方法等方面介绍了山杨接毛白杨的实用技术 ,并对嫁接后的管理也作了简要说明     

Agrobacterium-mediated transformation of lombardy poplar (Populus nigra L. var.italica Koehne) using stem segments

Genetically transformed lombardy poplar (Populus nigra L. var.italica Koehne) plants were regenerated by co-cultivation of stem segments withAgrobacterium tumefaciens strain LBA4404 that harbored a binary vector (pBI121) which included genes for β-glucuronidase (GUS) and neomycin phosphotransferase. Successful transformation was confirmed by the ability of stem segments to produce calli in the presence of kanamycin, histochemical and fluorometric assays of GUS activity in plant tissues, and Southern blot analysis.