FT-IR imaging and pyrolysis-molecular beam mass spectrometry: new tools to investigate wood tissues

Fourier transform infrared (FT-IR) microimaging spectroscopy and pyrolysis molecular beam mass spectrometry (py-MBMS) were used as rapid analysis tools to evaluate differences in the chemical composition of 1-year-old transgenic aspens. Multivariate analysis of the spectroscopic data sets was used to compare the cell wall composition of nontransformed control to transgenic aspen plants with GRP-iaaM gene and with GRP-iaaM/35S-ACCase gene. Principal component analysis (PCA) was applied to both the FT-IR and py-MBMS spectra, which revealed sample groupings due to differences in chemical composition. Evaluating the PCA loadings allows determination of the chemical features responsible for the groupings. The FT-IR microimaging data was also used to monitor changes in the chemical composition as a function of the distance from the pith to the bark using partial least squares (PLS) analysis. The analysis shows that the changes in the composition of the xylem that occur over one annual growth ring can be monitored with FT-IR microimaging.     

Puddling and N management effects on crop response in a rice-wheat cropping system

Coarse-textured soils are puddled to reduce high percolation losses of irrigation water under rice (Oryza sativa L.). This practice, however, reduces yield of succeeding wheat (Triticum aestivum L.) owing to deterioration in soil physical conditions. The 6 year field study reported in this paper evaluated the effects of puddling level and integrated N management on the development of subsurface compaction and growth and yield of rice and the following spring wheat grown in 1 year sequence on a sandy loam soil. Treatments were combinations of three puddling levels: low (one discing and one planking), medium (two discings and one planking), and high (four discings and one planking), and three nitrogen sources: (1) 120 kg N ha⁻¹ from urea, (2) 60 kg N ha⁻¹ from urea plus sesbania (Sesbania aculeata Pers.) green manure, and (3) 60 kg N ha⁻¹ from urea plus 20 Mg ha⁻¹ farmyard manure. Percolation rate decreased from 14 mm day⁻¹ with low puddling to 10 mm day⁻¹ with high puddling, with a corresponding reduction in irrigation water requirement of rice of about 20%. Bulk density profiles in the 0–30 cm soil layer showed the formation of a compact layer at 15–20 cm depth, and bulk density increased with puddling level and cropping season. The impact of organic amendments in reducing bulk density was immediate, but the rate of increase in bulk density with time was the same in all the nitrogen sources. Organic amendments did not affect percolation rate and irrigation requirement of rice. Rice yields were not significantly affected by puddling and N source treatments throughout the study period. Residual effects of treatments on wheat yield were observed from the second season onwards. Interactive effects of puddling and N source on yields of rice and succeeding wheat were not significant. Yield differences in wheat between high and low puddling were 8% and 11% during the second and the fifth cropping season, respectively. This study indicates that medium puddling was optimum, as it reduced percolation without decreasing yield of succeeding wheat.     

不同栽培袋材料对袋培黄瓜生长、产量及品 质的影响

以黄瓜品种津优30 为试材,以玉米秸秆∶牛粪∶炉渣=3V∶1V∶1V 为栽培基质,分别采用
底部（透水、不透水）编织袋、无纺布和双色膜为4 种栽培袋材料,进行日光温室黄瓜营养基质袋式栽培
试验,研究了不同栽培袋材料对黄瓜植株生长、伤流液、产量和品质的影响。结果表明：采用底部不透水
编织袋为栽培袋材料时,定值后40 d 及55 d 黄瓜的株高显著高于其他3 个处理,并且其植株地上部鲜质量、
地下部干质量、黄瓜伤流液中养分含量也显著高于其他3 个处理,果实可溶性蛋白、VC 含量都高于其他
处理。因此,底部不透水编织袋是适宜黄瓜袋培的栽培袋材料。     

Endogenous cytokinin levels of table grape vines during spring budburst as influenced by hydrogen cyanamide application and pruning

Cytokinins play an important role in budburst, flowering and fruit set in table grapes. Rest-breaking treatments with hydrogen cyanamide and pruning practices modify budburst and reproductive development in table grapes, especially in regions with low and often inadequate winter chilling. The effect of these treatments on the xylem sap and bud Zeatin riboside (ZR) content was determined during late winter and budburst in ‘Sultanina’, ‘Sunred Seedless’, and ‘Alphonse Lavalleé’ canes in a total of nine trials conducted between 1997 and 2001. Bud ZR levels of hydrogen cyanamide treated ‘Sultanina’ canes showed an earlier and increased cytokinin peak, in particular in the distal buds. Large ZR peaks before budburst and noticeable differences between distal and proximal buds were absent on non-sprayed canes. The xylary ZR content of long pruned ‘Sultanina’, ‘Sunred Seedless’, and ‘Alphonse Lavaleé’ canes showed a significantly higher and earlier cytokinin peak than in short pruned spurs. By contrast, the bud ZR content tended to be higher in spurs than canes. Pruning and rest-breaking treatments enhanced budburst and increased endogenous cytokinins in these experiments. Long pruning in ‘Sultanina’ and ‘Sunred Seedless’ (both parthenocarpic) is necessary for acceptable fruit set and yields. Possibly, in longer canes more cytokinin is available for reproductive development. ‘Alphonse Lavaleé’ (seeded) is sufficiently fruitful and produces adequate yields following spur pruning.     

Experimental reports on using "Penzhangjing" for Larix loptolepis

lntroductionTheprincipalcomp0nentpart0f"Penzhangjing"isBS(Brassin0ster0ide).BS,simiIart0Br(Brassinolide),isanewtype0fphytoster0lsgrowthregulat0randhasgreatlybi0logicaIactivity.TheInternationaIPlantGroWthMateriaIMeetingaffirmedBSasanewtype0fplanth0rm0nethatisdistinguishabIefr0mkn0wnplanth0rmone.Penzhangjingbased0nBsisac0m-poundofnutrienteIementsthatmanykinds0fplantsneed.withfunction0fsterilizingdisease.InfourteencitiesofLia0ningPr0vince,PenzhangjingSpreadingProb1emGr0upisengagedinex…     

Experimental reports on using “Penzhangjing” forLarix loptolepis

Experiments on spaying Penzhangjing on seedlings ofLarix leptolepis was conducted for a year. The height growth and diameter at foot of experimental seedlings increased by 34.3% and 35.5%, respectively, compared with control seedlings. Variance analysis concludes that Penzhangjing have obvious effect on growth of height and diameter at foot of seedlings. (Responsible Editor: Chai Ruihai)     

Decay development in living sapwood of coniferous and deciduous trees inoculated with six wood decay fungi

Development of decay and/or discoloration was assessed in the functional sapwood of one coniferous and three deciduous trees after wounding and artificial inoculation with six wood decay fungi. Living stems of mature Douglas fir, beech, oak, and sycamore trees were wounded in spring 2002 and immediately inoculated with brown, white, and soft rot fungi. Extent of discoloration and decay, wood weight loss, and total phenols in the reaction zone (zone of active response at a dynamic interface between living sapwood and wood colonized by decay fungi) were assessed 16 and 28 months after inoculation.     

Causes of defoliation and low survival rate of grafted sweet pepper plants

We investigated the cause of defoliation in sweet pepper (Capsicum annuum L.) plants after grafting. Grafted plants of old-stage sweet pepper showed a higher defoliation rate than young-stage grafted plants. Old-stage grafted plants had lower stomatal resistance and water potential than young-stage plants, and showed poorly developed xylem connections at the graft site. Foliar application of abscisic acid (ABA) to the grafted plants increased stomatal resistance and water potential, decreased the defoliation rate, and promoted graft take among old-stage plants. Our results indicated that low stomatal resistance under low humidity induces water stress, defoliation, and low survival rate in old-stage grafted sweet pepper plants. ABA treatment increased stomatal resistance, water potential, and survival rate, and decreased the defoliation rate among old-stage sweet pepper plants.     

内聚力学说不可能成立的依据

利用压力室技术测到的水势是缺乏修正的数值,比实际水势要高出许多,用该方法测定水势,只能反映出水势的大小变化,而不能用其代表木质部内真实的负压。蒸腾使木质部产生的负压最大不会超过-0．1Mpa,木质部内巨大负压的存在缺乏理论依据和直接的实验证据。空穴的必然发生使水柱无法保持连续,故连续水柱不存在。蒸腾状态下木质部水分的移动方式是自上而下分段依次移动的,这一现象与内聚力原理相抵触。蒸腾产生的负压能保持到蒸腾停止后继续使根系吸水。     

木本植物木质部栓塞的形成和修复的几点补充

对木质部栓塞的变化规律、不同的因素对栓塞的影响、栓塞的修复现象以及栓塞的修复机理进行了论述,在对以前的相关综述的基础上进行相应的补充。