O2和CO2浓度对黑木耳菌丝生长及出耳的影响

采用自行设计的培养装置,研究O2和CO2对2个黑木耳菌株菌丝培养和出耳的影响,结果:O2百分浓度为18.71%~20.38%时菌丝生长正常,为13.68%~17.45%时菌丝的生长受到显著抑制;为0.05%~3%对菌丝生长有促进作用,为3.17%~6.04%时菌丝生长受到抑制。CO2百分浓度为0.2%~3.5%可缩短出芽时间3~4 d;为18%~40%时对耳芽形成没有显著影响,高浓度氧气对木耳开片没有明显促进作用。     

The effect of plant density and day-length on growth and development in the carnation

Carnation plants cultivar ‘White Sim’ were grown in containers arranged to simulate the aerial environment of bed-grown crops. The effects of 2 plant densities (9 plants and 100 plants m^?2) and 2 day-lengths (natural days and continuous light) were recorded on the growth of individual plants. The reduction in yield of flowers per plant at high density was greater than could be accounted for simply by a reduction in light intensity. An interaction between light intensity and intra-plant competition is proposed as an explanation of this effect. Continuous light had little effect on the growth and flowering of 2nd and 3rd generation shoots grown at high density.     

3种植物生长延缓剂对温室甜瓜生长发育的影响

以厚皮甜瓜‘西洲密25号’为试验材料,采用3种植物生长延缓剂进行处理,探究其对温室厚皮甜瓜生长发育的影响。结果表明,与对照相比,3种植物生长延缓剂对厚皮甜瓜生长发育指标和产量的影响均达到显著水平。多效唑150 mg·L^-1的处理对蔓长、节间长的抑制效果以及对单瓜质量和总产量的增加效果达到极显著水平,矮壮素50 mg·L^-1处理对增加茎粗效果最为明显;多效唑250 mg·L^-1处理对叶柄长的抑制效果最明显;多效唑150 mg·L^-1与缩节胺200 mg·L^-1处理对增加叶绿素相对含量效果显著。缩节胺300 mg·L^-1处理对可滴定酸含量的增加作用最明显,缩节胺400 mg·L^-1处理减少可滴定酸含量;多效唑150 mg·L^-1处理对维生素C含量的增加作用最显著;多效唑50 mg·L^-1的处理对中心可溶性固性物含量的作用最显著;3种植物生长延缓剂处理对甜瓜硬度及果形指数均无明显影响。综上所述,多效唑150 mg·L^-1处理对厚皮甜瓜生长发育、果实品质及产量等相关指标的综合影响效果最显著,可为厚皮甜瓜温室栽培提供理论参考。     

Ventilation of culture vessels. II. Increased water movement rather than reduced concentrations of ethylene and CO2 is responsible for improved growth and development of Delphinium in vitro

Summary

Delphinium plantlets were cultured during Stage III in vessels modified to give different gas exchange rates. Modifications were achieved by the fitting of a covered aperture, or by the sealing of the lids. The concentrations of CO₂ and ethylene were measured in conjunction with measurements of relative humidity, water loss, the uptake of mineral nutrients and growth. Both CO₂ and ethylene concentrations were low in intact vessels, and significantly higher in vessels sealed with parafilm. Water loss was similar in intact and in sealed vessels, indicating that the vessel lid acted as a good barrier to water but allowed high rates of gas exchange. Plant growth rate was not affected by the level of ventilation of the vessels although leaf area was greater in vessels having lower gas exchange rates. After one week of culture, tissue concentrations of calcium and magnesium were highest in the vessels having the highest gas exchange rates. Relative humidity within the culture vessels was not affected by the level of ventilation. Improved stomatal performance, growth and survival of Delphinium from ventilated vessels appears to be due to an increased flow of water, and not to amelioration of the gaseous environment.     

植被和坡度对边坡稳定性的影响分析

边坡工程的稳定性问题是岩土工程的主要研究内容之一。随着我国经济、科技水平的不断发展和进步,人们对边坡稳定性的研究是从早期通过长期的观测统计出数据,慢慢发展到现在采用模拟试验来完成研究。边坡稳定性分析和评价是边坡工程研究的核心,在研究中人们发现:不同坡度对于边坡的稳定性有着不同程度的影响。本试验就从不同坡度条件下,有无植被2种坡度在降雨条件下进行研究分析。     

Profiling indoor plants for the amelioration of high CO2 concentrations

Research over the last three decades has shown that indoor plants can reduce most types of urban air pollutants, however there has been limited investigation of their capacity to mitigate elevated levels of CO₂. This study profiled the CO₂ removal potential of eight common indoor plant species, acclimatised to both indoor and glasshouse lighting levels, to develop baseline data to facilitate the development of indoor plant installations to improve indoor air quality by reducing excess CO₂ concentrations. The results indicate that, with the appropriate choice of indoor plant species and a targeted increase in plant specific lighting, plantscape installations could be developed to remove a proportion of indoor CO₂. Further horticultural research and development will be required to develop optimum systems for such installations, which could potentially reduce the load on ventilation systems.     

Simulated effects of increasing atmospheric CO2 and changing climate on the successional characteristics of Alpine forest ecosystems

Possible effects of changing climate and increasing CO₂ on forest stand development were simulated using a forest succession model of the JABOWA/FORET type. The model was previously tested for its ability to generate plausible community patterns for Alpine forest sites ranging from 220 m to 2000 m a.s.l., and from xeric to mesic soil moisture conditions. Each model run covers a period of 1000 yrs and is based on the averaged successional characteristics of 50 forest plots with an individual size of 1/12 ha. These small forest patches serve as basic units to model establishment, growth, and death of individual trees. The simulated CO₂ scenario assumes linear climate change as atmospheric CO₂ concentration increases from 310 l/l to 620 l/l and finally to 1340 l/l. Direct effects of increasing CO₂ on tree growth were modeled using tree-ring and growth chamber data. The simulation experiment proved to be a useful tool for evaluating possible vegetation changes that might occur under CO₂-induced warming. On xeric sites from the colline to the high montane belt, the simulated climate change causes drastic soil water losses due to elevated evapotranspiration rates. This translates into a significant biomass decrease and even to a loss of forest on xeric low-elevation sites. Biomass gains can be reported from mesic to intermediate sites between 600 and 2000 m a.s.l. Increasing CO₂ and warming alters the species composition of the simulated communities considerably. In today's montane and subalpine belt an invasion of deciduous tree species can be expected. They outcompete most conifers which in turn may migrate to today's alpine belt. Some of these changes occur as early as 40 yrs after climate begins to change. This corresponds to a mean annual warming of 1.5°C compared with today's mean temperatures.     

The influence of preplanting dips and postplanting temperatures on root growth and development of nonprecooled tulips,daffodils and hyacinths

The effects of preplanting dips and postplanting temperatures were studied, using nonprecooled bulbs of Tulipa gesneriana L. ‘Paul Richter’, Narcissus pseudonarcissus L. ‘Explorer’ and Hyacinthus orientalis L. ‘Pink Pearl’, for 2 consecutive years. Preplanting treatments consisted of a non-dip control, and 30-min dips of either tap water or benomyl—ethazol. After planting, the tulips and daffodils received temperatures of 5, 9, 13, 17 or 21° C for a 5-week period. Hyacinths received temperatures of 9, 13, 17, 21, 25, 29 or 33° C for 5 weeks in the first year and for 25 days in the second year.It was determined that 17° C for 3 weeks and 17° C for 3–4 weeks were the optimal temperatures and periods of time for root development of tulips and daffodils, respectively. For hyacinths, a range of from 17 to 25° C for 10–14 days was optimal. Under these conditions, a minimum root length of 70 mm was obtained and all bulbs of each species had rooted.The benomyl-ethazol and water preplanting dips stimulated root growth for the first 2 weeks for tulips. This effect was not observed for daffodils and hyacinths.     

Improved seed development and germination of stenospermic grapes by plant growth regulators

Plant growth regulators were applied to the foliage and immature fruit clusters of the stenospermic grape selection ‘C35-33’ at various periods before bloom to stimulate viable seed development. In the 1987 season five different plant growth regulators were used, but in 1988 the growth retardants Cycocel and XE-1019 were used exclusively. Chemical treatments applied 35 days after bud break increased significantly germination percentage. Experimental results indicate that the use of certain plant growth regulators may aid in increasing the efficiency of seedless grape breeding by providing an alternative to in-ovulo embryo culture.     

The influence of tree training and plant density on growth,yield components and yield of Arabica coffee cv. Ruiru 11

Assessment of tree growth and yield components of Coffea arabica L. cv. Ruiru 11, as influenced by tree training on single or two-stem systems at densities between 1600-4800 trees per ha during the first production cycle was carried out at Ruiru, Kenya over three years. Trees trained on the two-stem system tended to be taller than those on singlestems. Although the results were not clear, trees at low plant densities had thicker stems irrespective of the training system. The total number of primary branches was significantly higher on trees trained on the two-stem system. However, bearing primaries and productive wood were higher on the single-stem system during the first year of production. The number of bearing primaries and productive wood increased in subsequent production years on the two-stem system. Training trees on the two-stem system significantly depressed yields in the first production year by 245 to 842%, irrespective of plant density. Yields of clean coffee increased significantly with tree density irrespective of the tree training method. Yields over the production period increased by 33, 45,27 and 9% with increases in planting densities from 1600 to 2400, 2400 to 3200, 3200 to 4000 and 4000 to 4800 trees per ha, respectively. However, yields increased at a decreasing rate at densities above 3200 trees per ha. The proportions of the large grade ‘A’ sized coffee beans were not significantly affected by the treatments. It was concluded that it is possible to raise two stems during the first production cycle of ‘Ruiru 11’, although this might not be economical. Single stems would be preferred and a high plant density of between 3200-4000 trees per ha would be optimum during the first coffee production cycle.     

植物生长调节剂对库尔勒香梨树生育的影响

2006年用植物生长调节剂PBO、玉米素等在新疆兵团农二师二二三团的库尔勒香梨树(以下简称香梨树)上进行了应用试验,取得了较好的效果,现总结如下.     

The influence of ancymidol,chlormequat and daminozide on the growth and development of forced dahlia variabilis willd

Ancymidol, chlormequat, and daminozide were evaluated as growth retardants on forced dahlias. Only ancymidol was effective in reducing plant height, and at 0.25 to 2.0 mg per plant it did not affect the date of flowering, flower size, or the number of shoots produced from the tuberous roots. Treatment by soil drench was more effective than a foliar spray. The most consistent effects were obtained when ancymidol was applied 2 weeks after planting. Dahlia cultivars differed in the degree of response to ancymidol. Optimum rates must be determined for the cultivars which are suitable for pot plant forcing for spring marketing.     

The influence of photoperiod and plant density on yield of winter-grown gladioli in Queensland

The yields of inflorescences, corms and cormlets, and the inflorescence quality of winter-grown gladioli in south-east Queensland, were studied under 2 daylength regimes, 3 plant densities (150 000, 300 000 and 450 000 corms ha^?1) and 3 plant arrangements (bed, double row and single row). The daylength treatments were the natural daylength (12.3–14.5 hours) and a 24-hour photoperiod treatment in which natural daylengths were extended using incandescent light of an intensity of 150 lux. Two cultivars were used.Extending the photoperiod to 24 hours delayed flowering by approximately 15 days, and increased the number of inflorescences harvested from low, medium and high density treatments by 20, 91 and 169%, respectively, when compared to the inflorescence yield from these density treatments under natural daylengths. The quality of the inflorescences from the high-density treatment receiving the 24-hour photoperiod was similar or superior in all quality characteristics to that of inflorescences grown under the most favourable density treatment under natural daylengths (150 000 corm ha^?1). Plant arrangement had little effect on the number of days to flowering or inflorescence yield but inflorescence quality was improved when plants were grown in a double-row arrangement compared to those from the bed or single-row arrangements. Extension of the photoperiod had no effect on the number of new corms per plot. However, the average weight of new corms and the weight of cormlets per plot and per corm were reduced by approximately 32, 71 and 63%, respectively, when compared to the results obtained from plants grown under natural daylengths. These results suggest that flowers compete for available photosynthates with corms and cormlet development.The economic feasibility of extending photoperiod for the commercial production of winter-grown gladioli in south-east Queensland is discussed.     

The influence of sidewalk replacement on urban street tree growth

Interactions between tree roots and sidewalks can result in damage to sidewalks and when sidewalk damage is repaired adjacent tree roots are often severed. The objective of this study was to quantify the growth response of urban trees in restricted planting spaces pre- and post-sidewalk construction. The research included four trees species commonly planted along streets in Minneapolis and Saint Paul, Minnesota, USA. Species included were: Acer platanoides, Celtis occidentalis, Gleditsia triacanthos, and Tilia spp. Two street tree populations were sampled: trees adjacent to replaced sidewalk panels (<1.75 m) and trees on streets with sidewalk construction that were greater than 3 m from replaced sidewalk sections. In total, increment core samples from 292 trees were analyzed. Annual rings from each tree were measured and converted to basal area increment (BAI) for analysis. Comparisons of BAI were conducted between the two sample populations to assess differences in tree growth patterns. Pre- and post-sidewalk construction BAI was also evaluated to determine the influence of construction on growth trajectory. Growth response was quantified using resistance, resilience, and recovery indices. Species were found to differ in their response to construction disturbance. Planting space width was also found to influence post-construction growth. Tilia spp. had the highest resilience and fastest overall growth recovery post-sidewalk construction and A. platanoides exhibited the lowest resistance, resilience, and recovery post-sidewalk construction.     

An analysis of the growth of forced tulips. 2. Effects of low-temperature treatments during development on plant structure at anthesis

The effects of different periods of storage at low temperature on some plant parameters were examined at anthesis. The duration of the low-temperature storage affected the time taken for plants to reach anthesis, the stem lengths and shoot dry weights. However, flower size and dry weight scarcely altered with the duration of treatment.Despite large differences in the dry weights of the plant components at anthesis following different periods of low-temperature storage, the ratio of total plant dry weight at anthesis to the initial bulb dry weight at the commencement of treatment remained almost constant. Anthesis occurred in all treatments when the total plant dry weight fell to 70% of the original bulb mass.It is possible to relate flower quality to the fresh to dry weight ratio of the flower.     

WGD-2叶面肥与植物生长调节剂对澳洲坚果的保果效应

WGD-2是南亚热带作物研究所研制的用于澳洲坚果的保果叶面肥。以澳洲坚果品种Hinde(H2)为试材,研究了6个处理对澳洲坚果在幼果期和谢花至幼果形成期的保果效果。6个处理分别为清水对照(CK)、120mg·L-1WGD-2(T1)、120mg·L-1WGD-2+1mg·L-1NAA(萘乙酸)(T2)、120mg·L-1WGD-2+10mg·L-12,4-D(2,4-二氯苯氧乙酸)(T3)、120mg·L-1WGD-2+20mg·L-1CPPU(N-(2-氯-4-吡啶基)N'-苯基脲)(T4)、120mg·L-1WGD-2+40mg·L-1GA3(赤霉酸)(T5)。结果表明各处理在幼果期(果实直径0.5cm左右)施用均有不同程度的保果效果,2次施用效果具有累加效应,即重复施用可加强保果效果,以T1、T4处理效果最好。谢花至幼果形成期施用,T1和T4处理仍然具有累加效应;T2处理没有效果;T3处理重复施用刺激幼果脱落;T5处理具有刺激幼果脱落效应。在澳洲坚果生产中推荐WGD-2单独使用或与CPPU搭配使用,并严格控制WGD-2与植物生长调节剂搭配使用的质量浓度和处理时期。     

The influence of soil moisture stress and plant populations on the yield of pickling cucumbers

A 2-year study was conducted on the effects of irrigation and plant populations on yield of pickling cucumbers (Cucumis sativus L). The main plot treatments were no irrigation or irrigation at a frequency necessary to prevent the available soil moisture (ASM) from falling below 25 or 60%. The sub-plots consisted of 49 000 plants/ha (multi-harvest) or 123 000, 185 000 and 247 000 plants/ha (once-over harvest). Irrigation substantially increased the yield and improved the grades of both multi-harvest and once-over harvest pickling cucumbers. Highest yields were obtained from the multi-harvest operation with irrigation at 60% ASM level. Maximum yields were obtained with irrigation at 25% ASM level in the once-over harvest operation. All population densities of the once-over harvest operation produced similar yields when not irrigated. Increasing plant populations from 12 to 25 plants m^?2 did not significantly affect yields under irrigated conditions.     

The influence of far-red light on the development of tomato seedlings

The influence of far-red light on the development of tomato seedlings was investigated. It was found that a deficiency of it in the incident spectrum retarded stem elongation. The quantity of far-red light in the flux did not affect the number of flowers forming on the first truss or the time of anthesis.     

Effect of pruning and plant spacing on the growth of cherry rootstocks and their influence on stem water potential of sweet cherry trees

Summary

The aims of this work are to describe the effects of pruning and planting density on growth and water relations of ungrafted and grafted sweet cherry trees. A trial with cherry rootstocks ‘Prunus avium’, ‘CAB 11E’, ‘Maxma 14’, ‘Gisela 5’ and ‘Edabriz’ was begun in 1997. Pruning severities were applied to the rootstocks (0, 30, 60 and 90% of the vegetative growth was removed corresponding to P1, P2, P3 and P4 treatments, respectively) after planting to two plant spacings (S1 = 0.25 × 1.0 m and S2= 0.45 × 1.5 m). Canopy, root growth and leaf water potential (ψ_leaf) were quantified throughout the growing season. Pruning significantly affected root length and root weight of the rootstocks. Uncut plants (P1) showed a heavier and expanded root biomass (231 g and 108 m) than the intensively pruned plants (P4) (187 g and 75 m). The greater root biomass was obtained with the spacing/pruning combination, S1/P1 (285 g), and the smaller with S1/P4 (180 g) and S2/P4 (176 g). ψ_leaf varied significantly between the rootstocks and plant spacing but not with pruning. ‘Maxma 14’ and ‘P. avium’ attained the lowest values of midday ψ_leaf, –2.28 and –2.04 MPa, but the highest values of predawn ψ_leaf, –0.29 and –0.25 MPa, respectively. Generally, with high density (S1), the rootstocks exhibited lower predawn and midday ψ_leaf. In 1998, cultivars ‘Burlat’, ‘Summit’ and ‘Van’ were grafted onto rootstocks and a trial was installed in 1999. Predawn and midday stem water potential (ψ_stem) on cherry trees, measured in 2002, were affected significantly by the rootstock/genotype combination. Cultivars grafted on ‘P. avium’ and ‘Maxma 14’ showed the less negative midday ψ_stem, –1.36 and –1.42 MPa respectively, so these rootstock genotypes perhaps induced a higher drought resistance to the scion. Recorded data show that the scion-rootstock interaction with regard to production performance under water deficits may be an important consideration in cherry tree planting strategies.