不同栽培基质对菌根化枳实生苗生长和矿质元素含量的影响

以蛭石、珍珠岩、椰糠、泥炭作为介质,与土壤按照体积比1:1混合作为栽培基质,比较Glomus mosseae接种的枳Poncirus trifoliata实生苗在这些基质栽培下生长、菌根侵染率和矿质营养状况。结果表明,土+蛭石作为栽培基质最有利于菌根的侵染(73.58%)和苗木的生长(地上部干重、地下部干重和整个植株干重),土+椰糠混合的表现最差。以土+蛭石基质下菌根化枳实生苗叶片具有显著最高的磷、钙、锌、铁含量。因此,土+蛭石混合是一种高效的柑桔苗木菌根化栽培基质。     

不同pH值下接种AM真菌对枳橙苗生长及光合作用的影响

以枳橙Citrus sinensis×Poncirus trifoliata为试材,研究不同pH值(5.5～6.5,6.5～7.5,7.5～8.5)条件下接种丛枝菌根(AM)真菌摩西球囊霉Glomus mosseae对枳橙苗生长及光合能力的影响。结果表明,不同pH值水平下接种摩西球囊霉均能有效地侵染枳橙植株,菌根侵染率在65%以上;接种处理植株的菌根侵染率、株高、生物量干重、叶片叶绿素含量、光合作用速率和蒸腾速率等指标均显著高于不接种植株;接种AM真菌增强了宿主植物对碱性土的适应性。     

丛枝菌根真菌对酸枣水分状况影响

在塑料盆栽条件下,研究了丛枝菌根真菌对酸枣(Zizyphus spinosus Hu．)苗生长和水分状况的影响。结果表明,接种丛枝菌根真菌显著促进了植株生长,接种处理的苗高、叶数、地径、单株叶面积、茎和叶鲜重、干重、叶绿素含量都显著高于对照,苗高提高了21．9％～28．5％,叶干重增加了53．0％～73．2％。同时,接种后也提高了苗木的抗旱性,束缚水含量提高了17．2％～23．7％,显著提高了离体叶片的保水力;在干旱胁迫下,酸枣叶片推迟13～27．5h出现萎蔫,重新复水后,提前0．8～1h恢复正常。     

AM真菌与印度梨形孢对干旱胁迫下垂丝海棠生长发育和水分利用的影响

采用盆栽土培试验，研究丛枝菌根真菌处理（AM）、印度梨形孢真菌（PI）及其复合接种处理（AM+PI）对正常水分（WW）和干旱胁迫（DS）下垂丝海棠生长、生理特性及水分利用的影响。结果表明：无论正常水分还是干旱胁迫条件下，与不施菌剂处理相比，丛枝菌根真菌处理、印度梨形孢真菌处理和丛枝菌根真菌+印度梨形孢真菌处理均在一定程度上促进了垂丝海棠的生长，改善了植株光合生理，激活了抗氧化系统，提高了植株水分利用效率；丛枝菌根真菌处理在缓解干旱胁迫相关的生长发育及水分利用方面更为有效，而印度梨形孢真菌在促进内部生理代谢方面表现更佳。整体而言，干旱条件下丛枝菌根真菌+印度梨形孢真菌处理效果最为显著，叶片相对含水量比正常水分条件下对照提高了4.41%，水分利用效率提高了26.92%。综上，在干旱环境中接种丛枝菌根真菌、印度梨形孢真菌均可有效促进植物生长发育及相关生理代谢，前者主要通过表型改善缓解干旱胁迫，后者主要通过调节内在生理代谢实现，以复合接种效果最佳。     

干旱胁迫下AMF对盆栽枳实生苗生长和活性氧代谢的影响

在正常水分和干旱胁迫下,研究接种丛枝菌根真菌(AMF)Funneliformis mosseae对盆栽枳实生苗生长和活性氧代谢的影响。结果表明,6周的干旱胁迫显著降低了枳根系的菌根侵染率,抑制了植株的生长。接种AMF显著促进了干旱胁迫下枳植株的生长,显著降低叶片丙二醛、过氧化氢和超氧阴离子的含量,显著提高叶片超氧化物歧化酶(主要是Cu/Zn-SOD)、过氧化物酶和过氧化氢酶的活性。研究揭示了菌根化植株具有更高的抗氧化防御能力和抗旱能力。     

盐胁迫下丛枝菌根真菌对番茄吸水及水孔蛋白基因表达的调控

 采用盆栽试验研究不同浓度（0.5%和1.0%）NaCl胁迫下接种丛枝菌根真菌Glomus mosseae-2 对番茄吸水特性的影响,并用realtime-PCR技术分析了根系中5个水孔蛋白基因（LePIP1,LePIP2,LeTRAMP,LeAQP2,LeTIP）的表达。结果表明：盐胁迫下接种丛枝菌根真菌能促进植株生长和对水分的吸收,显著提高叶片相对含水量、叶片水势及根系水导;丛枝菌根真菌和盐胁迫共同调控了5个水孔蛋白基因的表达;与未接菌株相比,接种植株LeAQP2基因表达上调,其余4个基因表达下调。LeAQP2基因在接菌株根中的过量表达与盐胁迫下丛枝菌根真菌提高番茄根系水导有关。     

枳实生苗抗旱丛枝菌根真菌菌种比较的研究

 盆栽条件下研究丛枝菌根真菌Glomus versiforme、G. mosseae、G. geosporum、G. diaphanum 和G. etunicatum 对正常水分和水分胁迫下的枳实生苗水分代谢的影响。结果表明, 在正常水分和水分胁迫下接种丛枝菌根真菌都明显增加植株的生长, 提高叶片可溶性糖、可溶性淀粉、可溶性蛋白质以及根系可溶性糖的含量。叶片超氧化物歧化酶、过氧化氢酶和过氧化物酶活性增强, 从而提高了植株的抗旱性。正常水分下以接种G. versiforme的效果最好, 水分胁迫下以接种G. mosseae的效果最好。     

AM真菌接种和生草刈割对盆栽初生枳生长和土壤结构的影响

在温室中,研究了盆栽基质接种丛枝菌根(arbuscular mycorrhiza, AM)真菌摩西管柄囊霉Funneliformis mosseae对初生(种子播种育苗2个月后的幼苗)枳Poncirus trifoliata生长、菌根侵染、菌丝长度、土壤球囊霉素相关土壤蛋白(GRSP)含量和土壤结构的影响;同时研究了在AM真菌接种和柱花草间作条件下柱花草刈割对初生枳和柱花草生长、菌根侵染、土壤GRSP含量和土壤结构的影响。结果表明,与不接种相比,接种AM真菌显著地促进了初生枳生长,增加了土壤GRSP含量,并且土壤结构也得到改善。在AM真菌接种与柱花草间作的相同条件下,与柱花草未刈割相比,柱花草刈割对初生枳生长、菌根侵染、土壤GRSP含量和土壤结构均无显著性影响,但柱花草未刈割处理的菌丝长度是刈割处理的2.5倍。相关性分析表明,根际土壤大团聚体显著地与菌根侵染率、土壤GRSP含量和菌丝长度正相关,而生草刈割影响了丛枝菌根真菌菌丝长度,可能对土壤结构有不利影响。     

丛枝菌根真菌对香蕉试管苗植株生长和矿质营养吸收的影响

以Williams香蕉(MusaAAA)试管苗为材料,在温室盆栽条件下研究丛枝菌根真菌(AM真菌)对香蕉植株矿质营养和营养生长的影响。试验设3个处理,不接种对照和2个菌根接种处理:接种单一菌种Glomusversiform、接种混合菌种G.versiform、G.epigaeam、G.cadedonium。结果表明,香蕉植株的菌根侵染率为22.8%～32.9%;接种AM真菌促进了香蕉植株的营养生长,显著地增加地上部和根系的干重,其菌根依赖性达到30.8%～37.8%,植株的株高、叶片数和叶片长度略有提高;接种单一菌种增加了须根的数量,但2个接种处理均降低须根的长度,使得总根长减少;单一接种剂和混合接种剂分别显著提高植株的P和K含量,2个接种处理都显著地促进了植株对N、P、K的吸收,P增幅最大,为70%～120%,K的增幅次之,为80%左右,N的增幅最小,为40%～60%。结果还表明,混合接种剂的生长促进效果略好于单一接种剂。     

VA 菌根对果树的效应

VA 菌根参与果树生长发育的各个生理过程,进而产生对果树矿质营养、水分状况、抗病性、内源激素平衡状况、生长和产量等综合效应.栽植前对果树接种 VA 菌根即对苗木实行菌根化,是 VA 菌根在果树上应用的一条重要途径.     

Water deficit and polyethylene glycol 6000 affects morphological and biochemical characters of Pelargonium odoratissimum (L.)

The effects of water deficit and polyethylene glycol (PEG) 6000 on the growth and content of essential oil, photosynthetic pigments, soluble sugars, proline, macroelements (N–P–K) and microelements (Mg–Zn–Fe–Mn) of Pelargonium odoratissimum (L.) plants were investigated. Water deficits of 80% and 40% of field water capacity decreased certain growth characters (total leaf area, leaf number, and total fresh and dry mass). The photosynthetic pigments (chlorophylls a and b, total carotenoids) and mineral content (N–P–K–Mg–Zn–Fe–Mn) also decreased as water deficit level increased. Water deficit promoted the accumulation of essential oil content and its main components (methyl eugenol, isomenthone and limonene) as well as total soluble sugars and proline contents. The water deficit × PEG 6000 interaction was greater than water deficit treatments alone on all plant growth characters assessed.     

The Relative Importance of Stem and Root in Determining Rootstock Influence in Apples

Young clonal cacao trees have been grown under controlled soil moisture conditions for 20 months in a glasshouse. Weighable soil containers were used, and water was added to restore the soil to field capacity each time the total available water, which was about 40 lb. for each plant, had been depleted to 85% (wet treatment), 50% (medium treatment) or 15% (dry treatment). Plants were either given one of these treatments for the whole experiment, or one treatment was given during the natural dry seasons and another during the natural wet seasons.

Plants given a dry treatment at any time lost their apical dominance and flushed vigorously about 10 days after each watering, though many flushes subsequently withered. The other plants flushed normally, except that the continuously wet plants ceased to flush towards the end of the experiment. The mean expanded area of each leaf was greatest during wet and least during dry periods, and plants which had suffered the least soil moisture deficit throughout growth had the greatest net leaf area and dry weight accumulation. There was little difference in the rate of transpiration per unit leaf area between plants during periods of high compared to medium soil moisture, but the rate was less during dry periods. Dry weight increases both per unit of water transpired and per unit of net leaf area were greatest in the wettest plants.

There was little difference between the effects of the wet and the medium treatments on flower production or setting or on cherelle wilt, though ultimately slightly more pods ripened on the wet plants. Plants in a dry period developed few flowers, but initiation was apparently stimulated, for in a subsequent wet or medium period flowering was exceptionally heavy ; setting was poor and cherelle wilt high, however.

It is concluded that irrigation on a greater scale than is practised at present is likely to be beneficial to the growth and yield of cacao.     

土壤未灭菌条件下丛枝菌根对枳实生苗生长和抗旱性的影响

在温室盆栽土壤未灭菌条件下,以枳实生苗[Poncirus trifoliate(L.)Raf.]为试材,研究水分胁迫下丛枝菌根真菌Glomus mosseae对其生长、可溶性糖含量、水分利用效率和制造1 g干物质用水量的影响。结果表明,在正常水分和水分胁迫条件下,丛枝菌根增加或显著增加枳实生苗的生长量,显著或极显著地提高植株的水分利用效率和叶片、根系内的可溶性糖含量,菌根和水分交互影响根系可溶性糖含量,显著降低制造1 g干物质用水量,节约用水28.4％-31.1％,增强了枳实生苗的抗旱性。     

Interactions between root-zone temperature and light levels on growth,development and photosynthesis of Lycopersicon esculentum Mill. cultivar ‘Vendor’

Six-week-old tomato plants were subjected to 5 root-zone temperatures, ranging from 12 to 36°C, and 4 light levels in a factorial design. Large increases in shoot dry weight, leaf area and fruit development resulted from soil warming to 24°C when plants were grown under high light conditions. Shoot growth and fruit weight were reduced at 24°C root temperature under low light conditions. Total plant photosynthesis, leaf area index, net assimilation rates and leaf chlorophyll content were related to plant growth and flower development for the various treatments. Our experiments have shown an interaction between root-zone temperature and light levels for greenhouse tomatoes. Soil warming caused large increases in shoot dry weight and fruit development when light was not limiting plant growth, but had deleterious effects on flowering and fruit set under shaded conditions.     

水分亏缺逆境对温室黄瓜生长及有关物质代谢的影响

 不同土壤含水量对黄瓜生长影响很大: 土壤水分充足时, 植株生长健壮高大, 叶片舒展, 叶面积大。水分处理初期, 叶片脯氨酸、游离蛋白质含量随着土壤含水量的降低而增加, 水分处理时间延长则此趋势消失。叶片与根中亚精胺(Spd) 和腐胺(Put) 含量均随着土壤水分的减少而增加, 不同水分处理对黄瓜叶片与根中精胺(Spm) 含量的影响不大。叶片ABA 含量随着土壤含水量的减少而增加。     

Morphological,anatomical and physiological responses of Campylotropis polyantha (Franch.) Schindl. seedlings to progressive water stress

In this study we implemented a potted water supply experiment for 100 days by a completely random sole-factored design with five treatments: 100% (W₁₀₀), 80% (W₈₀), 60% (W₆₀), 40% (W₄₀) and 20% (W₂₀) of water holding capacity (WHC), corresponding to the soil volumetric water content (SVWC) maintained at 38.8 ± 0.3%, 31.6 ± 1.7%, 25.6 ± 1.3%, 16.5 ± 0.7%, and 8.1 ± 1.1%, respectively. The objective was to evaluate the ability of the 2-month-old Campylotropis polyantha (Franch.) Schindl. seedlings to tolerate drought and to explore the mechanism resisting drought. We monitored the growth process of seedling height and leaf number monthly and further investigated those changes in plant growth, dry mass accumulation and allocation, water-use efficiency (WUE), leaf functional traits, chlorophyll a fluorescence and pigment contents across the water deficit gradient. We found that the seedlings presented optimal growth, dry mass production, and physiological activity only at the W₁₀₀ and W₈₀ treatments and afterwards significantly decreased with progressive water deficit; the WUE was improved under moderate water stress (W₆₀ and W₄₀) but reduced under severe stress (W₂₀). The serious leaf shedding, growth stopping and seedling death under the W₂₀ condition revealed that the current-year shrub seedlings could not withstand severe drought. Water stress-induced decrease in total plant leaf area due to a combination of limited expansion of younger leaves and shedding of old leaves caused the leaf area ratio reduction under drought. The reduced mesophyll cell was a major anatomical response of leaves along the water stress gradient. The progressive water stress significantly damaged light harvesting complex and reduced photochemical processes and PSII activity. Our results clearly showed that the current-year shrub seedlings took the avoidance and tolerance mechanisms to withstand progressive drought stress and around 25.6% SVWC and around 12.3% SVWC separately are thresholds to limit the optimal growth and dry mass production and to last growing and surviving for the current-year shrub seedlings.     

Root growth,water relations and mineral uptake of young ‘Delicious’ apple trees treated with soil- and stem-applied paclobutrazol

Paclobutrazol (2R,3R + 2S,3S)-1-(4 chlorophenyl)-4,4-dimethyl-2-(1,2,4-trizol-1-yl) pentan-3-ol), at 25, 50 and 150 mg active ingredient, was applied as a soil drench or stem application to 1-year-old ‘Topred Delicious’ apples. Root growth measured as relative root surface area was reduced by both soil and stem applications. There was no significant difference in dry weight of the root tissue. The root-to-leaf-area ratio was significantly increased in paclobutrazol-treated plants.Water relations measured as leaf conductance and leaf water potential were significantly influenced by paclobutrazol. Leaf conductance was higher in paclobutrazol-treated plants when the plants were turgid, as well as under some water stress. Leaf water potential was significantly higher in treated plants.There were no significant differences in the total nitrogen, phosphorus, potassium and magnesium levels found in the leaf or root tissue.     

Changes in nutrient concentrations and leaf gas exchange parameters in banana plantlets under gradual soil moisture depletion

Changes in mineral nutrient concentration, growth, water status and gas exchange parameters were investigated in young banana plants (Musa acuminata cv. ‘Grand Nain’) subjected to gradual soil moisture diminution. Experiments were performed in glasshouse under controlled temperature, and water stress was imposed by ceasing irrigation for 62 days. The data showed a parallel decrease of leaf gas exchange parameters and soil moisture initiated few days after the imposition of water stress. However, the leaf relative water content (RWC) showed a minor decrease in response to drought. The onset of growth reduction evaluated as plant height, pseudostem circumference, number of newly emerged leaves, leaf area, and leaf and root biomass took place approximately between 34 and 40 days after the beginning of the stress period. In addition, drought did not modify nitrogen and phosphorus concentrations in foliar and root tissues; however, it increased potassium, calcium, magnesium, sodium and chloride in leaves, and only calcium, sodium and chloride in roots. Collectively, the data reveal that banana plants show a drought avoidance mechanism in response to water stress. After a prolonged drought period, leaf RWC was hardly reduced, while gas exchange and growth parameters were reduced drastically. Increasing leaf mineral concentration could have help to maintain leaf RWC due to osmotic adjustment mechanism.     

Moderating water stress in tomato (Lycopersicon esculentum Mill.) plants by application of specific nitrogen doses

Summary

The effect of different doses of nitrogen on water stress in tomato (Lycopersicon esculentum Mill. ‘Royesta’) plants grown in a sandy soil and exposed, or not, to long-term water stress was studied. Nitrogen dose treatments consisted of Hoagland’s solution (N1 treatment), Hoagland’s solution + 40 mM NO₃^– (N2 treatment), or Hoagland’s solution + 80 mM NO₃^– (N3 treatment) applied every 3 d, for a total of seven applications following plant establishment. Subsequently, daily application of 80% (stressed) or 100% (unstressed) of the water evapotranspired by control plants the previous day was combined, factorially, with the three nitrogen treatments, for a period of 2 weeks. The leaf fresh weight (FW) at full turgor:leaf dry weight (DW) ratio was high in plants under the N1 and N3 stress treatments, with no significant difference between them soon after the start and at the end of the water stress treatment. However, the N2 treatment produced a significant increase in the ratio in well-watered plants, but not in water-stressed plants at the end of the stress period. The surface area per leaf was greater in stressed than in control plants, except for N2. Leaf water potential was greatly reduced in stressed N2 and N3 plants, but was unaltered in their well-watered counterparts. The significant increases in relative water content at the turgor loss point (around 3%) and in cell membrane rigidity (an increase of more than 125% in the bulk modulus of elasticity) clearly indicate an osmotic adjustment in stressed N2 plants, confirming that this N dose moderated the effects of the water stress imposed on N2 plants.     

Effects of water deficit on olive trees cv. Chemlali under field conditions in arid region in Tunisia

Water scarcity in the Mediterranean basin in addition to the extension of irrigated lands is one of the main factors limiting agricultural development. The need for supplementary irrigation of the Chemlali olive cultivar (Olea europaea L.) during summer and autumn periods was investigated. Leaf water content, gas exchange parameters, fruit development and yield in rain-fed and in irrigated plants have been monitored in 12-year-old olive trees grown under environmental conditions in semi arid regions characterized by high temperatures and high light intensity. Trees were subjected to three irrigation treatments, T0, T1 and T2 corresponding respectively to 0, 33 and 66% of crop evapotranspiration (ET_c) by a drip irrigation system. The water deficit during the summer (from June to August) led to the decrease of soil moisture, leaf water content and gas exchange parameters. Irrigated trees showed the same slow activity in the three summer months as the rain-fed trees. For all treatments, net CO₂ assimilation, stomatal conductance and transpiration rates were markedly decreased by environmental conditions (high air temperature and high light intensity) during the summer period. At the partial active growth phase of the Chemlali olive cultivar (September–November), a significant re-increase in all parameters was observed. However, net photosynthesis and stomatal conductance of control plants (T0) were, respectively, 57 and 40% lower than those of plants conducted under milder water contribution (T1). The decrease of physiological activity in irrigated plants during hot and dry (summer time) and cold (winter) seasons was a clear evidence that water supply during such periods will be without a great benefit for photosynthetic activity, and thus growth, if applied under critical conditions inducing the rest phase of the plant. The non-statistically significant slight differences as well in photosynthetic performances activities (Pn, Gs and E rates), as in olive production between the two irrigated treatments will not cover the expenses of water loss when applying irrigation at 66% of ET_c especially in arid region characterized by scant and irregular rainfall. On the light of these results, we can conclude that the irrigation of this species during the vegetative growth phase (in spring and autumn), and stopping it during the olive rest phase (in summer and winter) could be recommended at least under the experimental conditions of this study; and that the contribution of 600 mm of water per year (33% of ET_c) can respond to the needs of the Chemlali olive cultivar in a semi arid region without impairing photosynthetic activity and olive production.