水培番茄侧根对盐胁迫的响应

以番茄品种石头为试材，采用分根水培装置，剪除主根同侧侧根，对番茄根系进行盐胁迫试验。设盐胁迫浓度分别 为0（CK）、0.1%、0.2% 和0.3% 4 个处理，通过测定侧根的根系活力、根系干质量和根系形态参数等指标，研究番茄根系 在盐胁迫下的生长状况和耐盐阈值。结果表明：侧根的生长符合慢- 快-慢的Logistic 生长模型，盐浓度为0.1% 的胁迫推 迟了根系的生育进程，根系活力、根系干质量和根系形态参数均高于对照；盐浓度为0.2% 和0.3% 的胁迫下根系生育进程 均提前，根系干质量和根系形态参数均较对照下降，根系生长受到抑制。当主根受到伤害会激发侧根的生存潜力，进行补偿 生长。根系的形态参数对耐盐性的贡献较大，总根长、根表面积和根体积可作为根系的耐盐指标。综上，对侧根生长有利的 盐胁迫环境为浓度0.1% 的盐溶液，通过Logistic 模型可以预测根系生长的始盛点、高峰点和盛末点，从而采取有效措施对 盐胁迫下侧根的生长进行调控。     

分根区交替灌溉对荔枝幼苗生长和水分利用的影响

通过盆栽试验研究不同水肥条件下,常规均匀灌溉、分根区交替灌溉、部分根干燥等3种灌溉方式对荔枝干物质积累、水分利用和生长性状的影响.结果表明,所有水肥条件下,常规灌溉处理根干重均低于分根区交替灌溉.高肥条件下,分根区交替灌溉处理叶片干重比常规均匀灌溉高9.1%,分根区交替灌溉处理耗水量减少22.3%～24.7%.低水低肥时,部分根干燥处理比其他灌溉处理少抽一次梢,分根区交替灌溉处理有几次抽梢数量比常规均匀灌溉少,枝梢较长,复叶数较多,生长量并未减少.     

干旱条件下断根对苹果幼树生长和光合特性的影响

控制地上部营养生长是果树生产中的一项重要工作。现以2年生盆栽苹果幼树为研究对象,分析了干旱条件下断根对苹果幼树生长发育和光合作用的影响。结果表明:干旱胁迫导致苹果叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)下降,提高了叶片的水分利用效率(WUE),而断根对这些指标没有显著影响。断根能够刺激苹果幼树产生大量新根,干旱条件下,断根处理后苹果根系再生能力显著下降。苹果春梢和叶片生物量,春梢长度和粗度,叶片长度、宽度和叶面积等营养生长特性都表现为T0T1T2T3的变化趋势。在干旱条件下进行断根处理,苹果叶片的光合能力和根系再生能力大大降低,春梢和叶片生长发育受到严重抑制。     

荔枝环剥时期对新梢生长及碳素储备的影响

 枝梢环剥显著抑制了‘怀枝’荔枝新梢的生长，并导致射线细胞和髓部大量积累淀粉。梢芽萌发或伸长前环剥可完全抑制新梢生长，而新梢快速伸长期环剥对其抑制效应最弱。秋季环剥对新梢的抑制和对淀粉积累的促进效应明显高于春季环剥。环剥口以上的老叶面积和环剥位置并不影响环剥对新梢生长的抑制效应和促进淀粉的积累效应，但环剥口以上单位枝梢长度的叶面积与淀粉含量呈显著正相关。     

非均匀盐胁迫对番茄幼苗耐盐性的影响

为了研究非均匀盐胁迫下番茄幼苗的光合特性和根系生长发育的状况,采用分根水培系统,设置3个总盐胁迫水平（NaCl浓度）处理——无盐胁迫（0）、中度盐胁迫（0.4%）和重度盐胁迫（0.6%）,按照左右两侧根系处于非均匀和均匀胁迫两种方式分成6个处理：T1（0,0）为对照,T2（0.1%,0.3%）,T3（0.2%,0.2%）,T4（0.1%,0.5%）,T5（0.2%,0.4%）,T6（0.3%,0.3%）,测定各个处理下番茄的光合指标、生物量、Na+和K+含量以及根系生长参数等。结果表明：（1）随着盐胁迫的加重,叶片中Na+含量增加,K+含量、光合指标、生物量和根系生长指标均依次降低;（2）在总盐（NaCl）浓度相同时,与左右两侧根系均匀盐浓度胁迫相比,非均匀胁迫下叶片中Na+含量显著降低（P < 0.05),气孔导度（Gs）与均匀胁迫下无显著差异,但净光合速率（Pn）、蒸腾速率（Tr）均增加,T2比T3处理下的Pn、Tr分别增加了4.88%和3.83%,T4处理下叶片的Pn、Tr分别比T6处理增加了13.51%和8.25%,T5处理下叶片Pn比T6处理增大了7.83%,Tr无显著差异;（3）当总盐浓度一定时,非均匀胁迫比均匀胁迫下两侧根系的总根长、根表面积、根体积以及总干物质量均有所增加。研究结果表明非均匀胁迫较均匀胁迫显著提高了番茄的耐盐性,这为番茄在盐碱地上的生长提供了耐盐胁迫的理论依据。     

砂土1/4根域施用有机肥对苹果幼树生长的影响

以2 a生有机玻璃箱栽植的分根苹果幼树为材料,研究1/4根域施用不同水平有机肥对苹果幼树新梢和根系生长的影响。结果表明,6月中旬以后,10%和30%有机肥处理的新梢二次生长旺盛;20%有机肥处理春梢段节数、占总新梢节数比例、叶面积、比叶重和春梢生长量均显著大于10%和30%处理,10%有机肥处理秋梢长度、节数、叶面积和比叶重均显著大于20%处理,秋梢补偿生长旺盛;不同比例有机肥处理调控梢类组成,10%和30%处理的长梢比例分别占总新梢22.2%和25.0%,而20%处理的仅占11.8%;除6月份外,20%有机肥处理根系总长度在果树整个生长季节内均显著大于10%和30%处理。砂性土壤局部施用适量有机肥可以调控新梢生长和根系的发育,为果园土壤局部改良、集中营养供应等提供理论依据。     

荔枝盆栽土添加蚓粪试验

研究了不同配比蚓粪处理对6叶龄荔枝品种禾荔实生幼苗新梢生长及根系构型的影响。结果表明,25%蚓粪是禾荔幼苗最佳施用量,明显促进幼苗地上部生长,增加根/冠比,优化根系构型;50%蚓粪处理效果与对照(100%园土)相似,过高浓度蚓粪处理(75%、100%)的幼苗生长显著受到抑制,根系生长量小,根系活力明显降低。     

水分胁迫对苗期番茄叶片保护酶活性和植株形态的影响

以"金粉2号"(‘Jinfen 2’)番茄为试材,设计3个土壤水分胁迫处理,即轻度(T1)、中度(T2)、重度(T3),以正常灌溉为对照(CK),于2014年4月25日至5月30日测定了叶片保护酶活性及植株形态指标,以研究土壤水分胁迫对番茄苗期植株形态指标和叶片保护性酶活性的影响。结果表明:随水分胁迫时间增加,叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量均有不同程度增加,同期内SOD、POD、CAT活性呈现CKT1T2T3趋势,MDA含量则表现为T3T2T1CK,且不同处理间存在显著差异。水分胁迫下,苗期后期番茄株高、茎粗、叶片数和叶面积指数均有不同程度的减小,尤其是重度胁迫T3处理减幅最大,分别仅为CK的61.0%、56.3%、60.1%和48.3%;轻度水分胁迫能显著促进根系的生长,T1处理的根系总表面积和根尖数比CK高34.5%和38.5%,而T2根系较于CK的优势随时间逐渐减弱,T3后期根系总长度、总表面积、平均直径和根尖数分别仅为CK的30.2%、34.5%、61.5%和32.7%;研究表明水分胁迫会抑制苗期番茄地上部分的生长,但是轻度胁迫能显著促进根系生长。短期的中度胁迫有利于根系生长,但随胁迫时间延长,这种促进作用逐渐减弱甚至转变为抑制作用。而在重度胁迫下,番茄根系则受到明显的抑制。     

平邑甜茶幼苗生长、根构型及吸收特性的容器调控

 以平邑甜茶[Malus hupehensis (Pamp.) Rehd.] 幼苗为材料, 研究了栽培容器形状对幼苗新梢生长、幼苗根构型特征及根系营养吸收特性的影响。结果显示, 生长在“深窄盆”中的幼苗新梢生长量最大, 主根粗, 侧根多且短, 毛细根丰富, 对钙及锌的吸收能力较强, 但根系活力及根系对磷、铁的吸收能力较弱; “等高径盆”中幼苗新梢生长量小, 根冠比接近1, 主根细短、一级侧根少且粗长, 对钾的吸收能力较强; “浅宽盆”幼苗根冠比最大, 一级侧根数量、长度和粗度居中, 二级侧根粗长, 根系活力及根系对磷、铁的吸收能力较强, 但对钾、钙及锌的吸收能力弱。     

干旱胁迫下菌根真菌对枳根系形态、内源激素和土壤结构的影响

季节性干旱是限制柑桔品质和产量的重要因素之一。以盆栽枳实生苗为试材,研究了干旱胁迫下接种丛枝菌根真菌对枳根系形态、内源激素水平和根际土壤结构的影响。结果表明,干旱胁迫显著降低了菌根真菌对枳根系的侵染。在正常水分和干旱胁迫下,接种菌根真菌显著提高了根系总长、投影面积、表面积、2级侧根数和3级侧根数,降低了平均直径,显著促进了脱落酸、赤霉素、吲哚乙酸和油菜素内酯在根系的积累。干旱胁迫下,菌根处理显著提高了枳根际总球囊霉素相关土壤蛋白含量,增大了1~2mm和0.5~1mm水稳性团聚体比例以及平均质量直径。结果暗示了菌根真菌可通过改善根系形态、调节内源激素平衡和改良土壤结构来提高枳的抗旱性。     

非灭菌土接种AM真菌对油蒿抗旱性的影响

利用盆栽试验在正常水分和干旱胁迫条件下研究了非灭菌土接种AM真菌摩西球囊霉(Glomus mosseae)和土著AM真菌(Indigenous arbuscular mycorrhizal fungi)对油蒿(Artemisia ordosica)生长及抗旱性的影响。结果表明:干旱胁迫显著抑制了AM真菌对油蒿的侵染。无论在正常水分还是干旱胁迫条件下,接种AM真菌都增加了植株的分枝数、地上部鲜重和干重、地下部鲜重和干重,但没有明显提高株高、茎粗和改善组织水分状况;与未接种相比,干旱胁迫下接种土著AM真菌显著提高了根系氮、磷含量,提高了叶绿素、可溶性蛋白含量,增强了保护酶超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性并降低了丙二醛的含量,因此增强了植物的抗旱性。     

Responses of field grown tomato plants to arbuscular mycorrhizal fungal colonization under varying intensities of drought stress

The effects of root colonization by the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck and Smith on growth, flower and fruit production, and fruit quality were studied in field-grown tomato plants exposed to varying intensities of drought stress. Inoculated (M+) and non-inoculated (M−) tomato seedlings were exposed to varying intensities of drought stress by adjusting irrigation intervals. Mycorrhizal plants had significantly higher uptake of N and P in both roots and shoots regardless of intensities of drought stress. AM inoculation also significantly increased shoot dry matter and the number of flowers and fruits. The fruit yields of M+ plants under severe, moderate, mild drought-stressed conditions were higher than M− plants by 24.7%, 23.1%, 16.2% and 12.3%, respectively. Furthermore, M+ plants produced tomato fruits that contain significantly higher quantities of ascorbic acid and total soluble solids (TSS) than M− plants. Mycorrhizal effects increased with increasing intensity of drought. The overall results suggest that mycorrhizal colonization affects host plant nutritional status, water stratus and growth under field conditions and thereby alters reproductive behaviour, fruit production and quality of fruits under both well-watered and drought-stressed conditions.     

Transpiration,photosynthetic responses,tissue water relations and dry mass partitioning in Callistemon plants during drought conditions

Callistemon is an Australian species used as ornamental plant in Mediterranean regions. The objective of this research was to analyse the ability of Callistemon to overcome water deficit in terms of adjusting its physiology and morphology. Potted Callistemon laevis Anon plants were grown in controlled environment and subjected to drought stress by reducing irrigation water by 40% compared to the control (irrigated to container capacity). The drought stress produced the smallest plants throughout the experiment. After three months of drought, the leaf area, number of leaves and root volume decreased, while root/shoot ratio and root density increased. The higher root hydraulic resistance in stressed plants caused decreases in leaf and stem water potentials resulting in lower stomatal conductance and indicating that water flow through the roots is a factor that strongly influences shoot water relations. The water stress affected transpiration (63% reduction compared with the control). The consistent decrease in g_s suggested an adaptative efficient stomatal control of transpiration by this species, resulting in a higher intrinsic water use efficiency (P_n/g_s) in drought conditions, increasing as the experimental time progressed. This was accompanied by an improvement in water use efficiency of production to maintain the leaf water status. In addition, water stress induced an active osmotic adjustment and led to decreases in leaf tissue elasticity in order to maintain turgor. Therefore, the water deficit produced changes in plant water relations, gas exchange and growth in an adaptation process which could promote the faster establishment of this species in gardens or landscaping projects in Mediterranean conditions.     

水分胁迫对费菜和长药八宝生长及生物量分配的影响

 研究了土壤水分胁迫对景天属植物费菜（Sedum aizoon L.）和长药八宝（Sedum spectabilis Boreau）的生长以及生物量分配的影响。结果表明：两种植物的生长及生物量分配状况均受土壤水分胁迫的影响。随着水分胁迫的加剧，费菜和长药八宝的株高、叶片数量、单株总叶面积及生物量增量总体均呈下降趋势，且费菜生长受抑制程度高于长药八宝；生物量分配比例发生变化，根冠比总体表现为先上升后下降。此外，水分胁迫还降低了植株含水量，费菜的降低幅度远大于长药八宝。研究表明，长药八宝较费菜更能适应干旱胁迫环境。     

Seasonal Changes of Shoot Carbohydrates and Growth Characteristics of ‘Trakya İlkeren’ Grape Variety (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.)

This research was conducted to determine the changes in the seasonal carbohydrates of annual shoots and growth characteristics of 10 years old ‘Trakya ?lkeren’ grape variety. Grapevines are grafted on 5BB and 5C rootstocks and they were grown in heavy clay soil conditions. In the study, changes of sugar, starch and total carbohydrates were determined from bud burst to dormancy. While sugar, starch and total carbohydrates showed significant differences (P < 0.01) there were no differences between rootstocks. Although sugar, starch and total carbohydrates of shoots decreased from bud burst to blooming, they increased thereafter until vegetative growth stopped. Total carbohydrates of annual shoots have been found to accumulate in period from blooming to harvest. Total and mean leaf area, shoot length and diameter, total chlorophyll and chlorophyll a/b ratio showed significantly variation among rootstocks and phenological stages (P < 0.01). Whereas the highest chlorophyll contents were found in the blooming, it was found at the lowest through to harvest. Overall mean and total leaf area, shoot length and shoot diameter, total chlorophyll content and chlorophyll a/b ratio were significantly higher on 5BB grafted vines. In the study, 5BB rootstocks are found suitable in terms of shoot carbohydrate accumulation and growth characteristics for ‘Trakya ?lkeren’ grape variety.     

Root and shoot growth of newly-transplanted apple trees as affected by rootstock cultivar,defoliation and time after transplanting

Summary

An experiment with Malus demonstrated that a large proportion of the transplanted root system was lost through death and decomposition soon after transplanting in the open ground. Mortality of the roots was not influenced by the rootstock cultivars or by defoliation but increased significantly with time. In the first month, shoots of maiden trees of Malus transplanted in June when in-leaf grew, but roots did not. Subsequently, most of the new roots on the rootstock M.9 regenerated from the rootstock stem, whereas with MM.106 the old coarse roots (>2.0 mm diameter) initially present at planting were most important. Root growth occurred in concert with shoot growth such that a functional balance was maintained as shown by the existence of a constant root length:leaf area ratio over a large part of the growing season. Following transplanting, the trees appear to re-establish their optimal ‘functional’ ratio by way of a co-ordinating pattern of growth tending to correct any disturbance to the ratio resulting from transplanting. Defoliation in the early establishment phase caused only a temporary initial reduction in the root growth, but reduced all the shoot growth variables measured and increased the root length:leaf area ratio throughout the growing season.     

Effect of Hydrogen Cyanamide on Vegetative Growth,Yield, and Fruit Quality of Fig cv. Zidi in a Warm Production Area

The fig tree (Ficus carica L.) is widely cultivated in the Mediterranean region under warm climates. Fig yield is governed by the previous crop load and is strongly dependent on shoot length. Special cultural practices are required to stimulate new vegetative growth that will ensure regular and high productivity. The present study focused on the use of the rest breaking agent hydrogen cyanamide (HC) as Dormex to enhance vegetative growth, which influences the yield. A field trial was held in northern Tunisia (36° 49′ N; 9° 48′ E) on mature fig trees cv. Zidi. In reference to untreated trees as control, two hydrogen cyanamide treatments at 1% and 1.5% HC were considered. Bud break rate, vegetative growth, starch content of shoots, yield, and fruit characteristics were assessed. Results indicated that 1.5% HC significantly increased shoot length, fruit number per shoot, and yield. It advanced bud break by 10 days and fruit ripening by 7 days compared to the control. However, leaf number, leaf area, and starch content seem to be unaffected by hydrogen cyanamide treatments. Regarding fruit quality, a 1.5% HC dose significantly increased dry matter content, while fruit diameter and total soluble solids remain unaffected. In conclusion, hydrogen cyanamide could be used under warm conditions to improve vegetative growth of fig trees cv. Zidi and consequently fig productivity. Application of 1.5% HC 40 days before bud break was the most effective in increasing shoot length and yield.     

Evaluating variability of root size system and its constitutive traits in hot pepper (Capsicum annum L.) under water stress

The importance of root size system has long been recognized as crucial to cope with drought conditions. This investigation was conducted to: (i) evaluate the variability in root size system of hot pepper at maturity; (ii) estimate the effect of root size system on yield under drought conditions; and (iii) effect of water stress on xylem vessel development and total xylem cross-sectional area in roots of hot pepper cultivars. Twelve diverse hot pepper cultivars were grown in wooden boxes with two different water treatments, normal and in 50% water application as water deficit condition. Mean primary root length (PRL) showed a significant positive correlation with final fruit yield at normal as well as stressed condition. Total dry mass of fruit was reduced by 34.7% in drought treatments (DI) compared to full watered treatment (FI). At harvest, water-stressed plants had 21% lower root dry weight mass but higher root:shoot ratio other than FI. PRL, lateral root density, total xylem area per root cross-section showed a significant positive relationship with fruit yield. Also, lateral root density was higher in cultivars with higher xylem density, particularly in tolerant cultivars. Lateral root density (r = 0.847, P < 0.001) and total xylem cross-sectional area in root (r = 0.926, P < 0.001) were tightly related with total biomass production. The importance of root traits contributing to withstand drought in hot pepper is discussed.     

Effect of alleviating products with different mode of action on physiology and yield of olive under drought

Two years old self-rooted Koroneiki olive trees (Olea europaea L.) were subjected to two irrigation regimes, i.e. the fully irrigated and the severely water stressed trees, while they were treated with three alleviating products of different mode of action. The products used were the osmolyte glycine betaine, the antioxidant Ambiol and the heat and irradiance reflecting kaolin clay particles. The effects of product application and water regime on leaf characteristics, shoot and root growth, photosynthesis, leaf compatible solids (carbohydrates) concentration and yield were evaluated. All products applied, exhibited significant alleviating action, based on the relative alleviation index. Irrigated trees exhibited greater growth than drought stressed ones, while the ameliorating products maintained the water content of the leaves under drought conditions and resulted in lower leaf tissue density. On the other hand carbon assimilation rate, stomatal conductance and intrinsic water use efficiency were significantly reduced under drought stress, while the opposite stood for intercellular CO₂. Drought stress resulted in elevated sucrose leaf concentration, while the application of Ambiol increased stachyose concentration and that of glycine betaine did the same with the mannitol concentration. Among the alleviating products tested in this experiment Ambiol and glycine betaine had a significant positive effect on leaf water content, photosynthesis and yield under both drought and well irrigated conditions.     

Effects of AMF inoculation on growth of Panax ginseng C.A. Meyer seedlings and on soil structures in mycorrhizosphere

We aimed to investigate the effects of inoculating Panax ginseng C.A. Meyer seedlings with arbuscular mycorrhizal fungi (AMF) by examining the root colonization, plant nutrition uptake, growth characteristics, and soil aggregation of P. ginseng seedlings inoculated at the time of transplantation. At 16 weeks, the AMF spore density per 30 g of fresh mycorrhizosphere in seedlings inoculated with AMF (AMF+ seedlings) was 256.8 and that in seedlings not inoculated with AMF (AMF− seedlings) was 186.3, respectively. The colonization rate of AMF in the lateral roots of AMF+ seedlings was approximately 19% higher than that in the lateral roots of AMF− seedlings. The patterns of AMF colonization in ginseng roots were similar to those of the Paris-type mycorrhizal association. Plant growth characteristics, such as plant height, root length, leaf area, number of lateral roots, fresh weight of shoots and roots, and chlorophyll content, were significantly enhanced in AMF+ seedlings compared to AMF− seedlings. The macronutrient content (P, K, and Ca) and micronutrient content (Cu, Fe, and Zn) of both shoots and roots were also significantly higher in AMF+ seedlings compared to AMF− seedlings. Furthermore, glomalin content and soil aggregation were significantly enhanced in AMF inoculated areas. Our results indicate that AMF inoculation may enhance the growth of ginseng seedlings by improving the uptake of mineral nutrients and the soil structure in mycorrhizosphere.