EFFECT OF DIFFERENT ROOTSTOCKS ON GROWTH,CHLOROPHYLL A FLUORESCENCE AND MINERAL COMPOSITION OF TWO GRAFTED SCIONS OF TOMATO

Two tomato scions (cvs. ‘Raf’ and ‘Gorety’) were grafted on three different rootstocks: S. torvum, ‘Beaufort’ (Lycopersicum esculentum × Lycopersicum hirsutum) and intermediate grafting of eggplant ‘Cristal’ between tomato and S. torvum (double graft). Plants were grown in Mediterranean greenhouse conditions. The response to grafting was measured through growth parameters, F_v/F_m and leaf macronutrients analysis, and it was compared with non-grafted plants. The scions grafted on S. torvum in simple and double graft showed lower fresh and dry weight of leaves, number of commercial fruits, plant height, F_v/F_m and decreased their capacity to absorb several nutrients resulting in a lower mineral concentration in scions leaves, as a result of a thickened graft union. On the other hand, both scions showed a good response when grafted on the rootstock ‘Beaufort’, with which growth parameters, yield and photosynthetic capacity were similar to non-grafted plants.     

EFFICACY OF SUPPLEMENTAL CALCIUM ON THE GROWTH OF THREE RICE GENOTYPES DIFFERING IN SALT TOLERANCE

The effect of supplemental calcium (Ca) on the growth of three rice genotypes PVSB9, NS15, and Pokkali were assessed. Different morphological characters were studied among which the percent relative- plant height, total tillers, root dry weight (RDW), shoot dry weight (SDW), and total dry matter (TDM) were higher in Pokkali and PVSB9, but lower in NS15 under different salinity and supplemental Ca levels. These morphological characteristics significantly decreased with increasing salinity levels grown at different Ca levels, but significantly increased with increasing supplemental Ca levels. The interaction effect of genotypes and salinity levels, and genotypes and Ca levels were significant, where a negative relationship with increasing salinity levels and a positive relationship with increasing supplemental Ca levels were found. The interaction effect of salinity and Ca levels on all morphological parameters was significant, where these characteristics increased due to increasing the supplemental Ca levels at all the levels of salinity.     

大麦盐害及耐盐机理的研究进展

大麦是禾谷作物中较为耐盐的粮食作物。然而在盐胁迫环境下,Na+能把膜系统中的其他离子置换下来,使细胞过多地吸收Na+和Cl-,从而导致细胞膜系统受损、DNA降解、植物营养亏缺、生理干旱以及细胞死亡等伤害。大麦自身在受到盐分胁迫下,耐盐机制有:离子的选择性吸收、拒盐排盐性、渗透调节物质的合成以及离子在植株体内的运输交换。进行大麦耐盐性选择时,萌发力、耐盐指数、Na+/K+和渗透调节物质的合成能力,都是比较重要的选择标准。基于大麦较好的耐盐性,可通过遗传育种改良、化学控制、耕作等措施和途径提高大麦的耐盐抗盐能力,减轻盐害,提高大麦产量和品质。     

盐胁迫和AM真菌对生菜生长的效应

试验设不接种、接种Glomus intraradices（BEG141）、接种Glomus mosseae（BEG167）3个接种处理，每个接种处理下再设电导率（EC）为607μScm^-1（低盐）、1236μScm^-1（中盐）、1866μScm^-1（高盐）等3个不同盐水平处理。试验结果表明：随着土壤EC值的增加，生菜生物量降低，但在低盐胁迫下，非菌根植株降低幅度大于菌根植株。与不接种处理相比，在低盐和中盐条件下，接种菌根真菌的植株体内NO3^-含量、植株地上部干重增加；同一土壤盐水平下，接种处理的植株磷、叶绿素含量高于不接种处理的；在低盐下，接种处理的植株的根系可溶性糖含量高于不接种处理的，但在1236和1866μScm^-1的盐度下，接种处理的植株根系可溶性糖含量低于不接种处理的。说明在施肥过量引起的次生盐渍化土壤中，AM真菌侵染对生菜在低盐胁迫下的生长存在促进作用，而在高盐胁迫下，使其生长受到抑制。     

EFFECT OF PACLOBUTRAZOL AND PUTRESCINE ON ANTIOXIDANT ENZYMES ACTIVITY AND NUTRIENTS CONTENT IN SALT TOLERANT CITRUS ROOTSTOCK SOUR ORANGE UNDER SODIUM CHLORIDE STRESS

The effects of paclobutrazol (PBZ) and putrescine (Put) on antioxidant enzymes activity, proline contents and nutrients uptake were studied on salt tolerant citrus rootstock sour orange. Six-month-old nucellar seedlings grown in pots and subjected to three levels of PBZ and two levels each of salinity and Put for 90 days. Seedlings treated with PBZ or Put alone or in combination had higher anti-oxidant enzymes activities, accumulation of proline and nutrients contents like potassium (K⁺) and calcium (Ca²⁺) under both saline and non-saline conditions. Further, application of PBZ or Put alone or in combination also reduced the accumulation of both Na⁺ and Cl^? ions in leaves and roots in NaCl stressed seedlings. A combined application of 250 mg L^?1 PBZ and 50 mg L^?1 Put proved to be more effective in improving proline and Ca²⁺ content and restricting accumulation of Na⁺ ions in leaf tissues.     

DETERMINATION OF FOLIAR SAMPLING CONDITIONS AND STANDARD LEAF NUTRIENT LEVELS TO ASSESS MINERAL STATUS OF LOQUAT TREE

Loquat [Eriobotrya japonica (Thunb.) Lindl.] is a minor fruit-tree species which is grown commercially in the Mediterranean region. Given the current increase in loquat cultivation, there is a need to define basic crop-management procedures in order to obtain high yields and optimal fruit quality. The aim of this work was to develop a routine for loquat farmers to follow, in order to know the nutritional status of trees in order to establish a rational fertilization regime, and to correct nutrient deficiencies as soon as possible. This paper reports three experiments aimed at establishing: 1) leaf type, 2) time of leaf sampling and 3) the standard leaf nutrient levels as a function of maximum yield. Results indicate that the summer flush leaves could be the most representative of nutritional status. Thus, the most appropriate time to sample leaves for analysis is in summer (beginning of August to the end of September), taking mature 3–4 month old leaves.     

EFFECTS OF SALINITY AND SOIL ZINC APPLICATION ON GROWTH AND CHEMICAL COMPOSITION OF PISTACHIO SEEDLINGS

The effects of four salinity levels [0, 1000, 2000, and 3000 mg sodium chloride (NaCl) kg^?1 soil] and three zinc (Zn) levels [0, 5, and 10 mg kg^?1 soil as zinc sulfate (ZnSO₄.7 H₂O)] on growth and chemical composition of pistachio seedlings (Pistacia vera L.) cv. ‘Badami’ were studied in a calcareous soil under greenhouse conditions in a completely randomized design with three replications. After 26 weeks, the dry weights of leaves, stems and roots were measured and the total leaf area determined. Salinity decreased leaf, stem, and root dry weights and leaf area, while this effect diminished with increasing Zn levels. Zn fertilization increased leaf, stem and root Zn concentrations, leaf potassium (K) concentration, and stem and root sodium (Na) concentrations, while decreased leaf Na concentration, and stem and root K concentrations. Salinity stress decreased leaf, stem, and root Zn concentrations, and leaf K concentration, while salinity increased leaf, stem and root Na concentrations, and stem and root K concentrations. Proline accumulation increased with increasing salinity levels, whereas the reverse trend was observed for reducing sugar contents. Zn application decreased proline concentration but increased reducing sugar contents. These changes might have alleviated the adverse effects of salinity stress.     

THE EFFECTS OF NITROGEN SOURCE AND CONCENTRATION ON THE GROWTH AND MINERAL COMPOSITION OF PRIVET

Abstract

Sodium (Na) movement between plants and humans is one of the more critical aspects of bioregenerative systems of life support, which NASA is studying for the establishment of long‐term bases on the Lunar or Martian surface. This study was conducted to determine the extent to which Na can replace potassium (K) in red beet (Beta vulgaris L. ssp vulgaris) without adversely affecting metabolic functions such as water relations, photosynthetic rates, and thus growth. Two cultivars, Ruby Queen and Klein Bol, were grown for 42 days at 1200 μmol mol^?1 CO₂ in a growth chamber using a re‐circulating nutrient film technique with 0%, 75%, 95%, and 98% Na substitution for K in a modified half‐strength Hoagland solution. Total biomass of Ruby Queen was greatest at 95% Na substitution and equal at 0% and 98% Na substitution. For Klein Bol, there was a 75% reduction in total biomass at 98% Na substitution. Nearly 95% of the total plant K was replaced with Na at 98% Na substitution in both cultivars. Potassium concentrations in leaves decreased from 120 g kg^?1 dwt in 0% Na substitution to 3.5 g kg^?1 dwt at 98% Na substitution. Leaf chlorophyll concentration, photosynthetic rate, and osmotic potential were not affected in either cultivar by Na substitution for K. Leaf glycinebetaine levels were doubled at 75% Na substitution in Klein Bol, but decreased at higher levels of Na substitution. For Ruby Queen, glycinebetaine levels in leaf increased with the first increase of Na levels and were maintained at the higher Na levels. These results indicate that in some cultivars of red beet, 95% of the normal tissue K can be replaced by Na without a reduction in growth.     

矿质营养对绿萍生长的影响

近年来,稻田养萍在我国福建、浙江、广东、广西及江苏等省发展很快,并已在中、晚稻田中获得了养萍成功经验.但养萍过程中的施肥技术,至今尚未得到很好的解决.本文试图探讨绿萍生长与矿质营养的关系,以便为其合理施肥提供根据.     

AM真菌和施氮量对烟叶生长和部分矿质元素含量的影响

采用土培试验研究了不同施N水平下接种AM真菌摩西球囊霉(Glomus mosseae)对烤烟不同叶位烟叶生长和部分矿质元素含量的影响。结果表明,接种AM真菌提高了烟草根系菌根侵染率,增加了烟叶总干重,其中对下位烟叶效果明显。在低N水平下,接种AM真菌提高了烟叶中N、K、Fe含量,在下位叶表现尤为显著。较高N水平下,提高了P含量,在3个叶位都有体现。Mg含量随施N量增加而提高,但处理与对照间差异不明显。施氮量为0.05~0.2g/kg土时,AM真菌接种效果最佳。     

碳酸盐及甲硫氨酸对抗盐碱水稻根系发育的影响

以12个黑龙江省主要栽培的具有不同抗盐碱性水稻品种和7个碳酸盐抗性突变体品系的种子为材料,分别用0.02%甲硫氨酸或0.2%碳酸钠进行处理,并以0.5%琼脂培养基为对照培养,10d后调查种子根的长度、侧根数量等。结果表明,7个突变体材料经甲硫氨酸和碳酸钠处理后,侧根数和种子根长均比对照有明显的减少;而原品种没有显示出差异。突变体材料吸收碳酸盐量明显减少,抗性得到了提高。12个栽培品种材料经甲硫氨酸处理后,侧根数较对照有明显的减少;大多数种子的根长较对照无明显变化,少数种子根长较对照发生正向式负向变化。经碳酸钠处理后,侧根数和种子根长均明显变少和变短。因此经甲硫氨酸和碳酸钠处理10d后的侧根数和根长的负向极显著变化可成为衡量水稻抗盐碱的一项新指标。     

苹果矮化砧对~(14)C-同化物运输分配的影响

采用14 C示踪方法研究了苹果不同砧木和砧穗组合植株对14 C 同化分配的影响。结果表明 ,矮砧及其嫁接植株的地上部分总干物质分配比例比乔砧及其嫁接植株高 1 4 %和 9 4% ,14 C 同化物分配比例高 1 9 2 %和 1 5 7% ;与乔砧相比 ,矮砧新梢、主干14 C放射比强度都较高 ;矮化中间砧红星新梢的放射性比强度是乔砧红星的 1 78倍 ,矮化中间砧段14 C存留量是相应乔砧植株干段的近 3倍 ,但矮化中间砧段上接口及其上部主干中并未有14 C 同化物积累。因此 ,矮化中间砧对同化物分配的影响并非简单的运输阻滞     

EFFECTS OF MYCORRHIZAL FUNGI ON TOLERANCE CAPABILITY OF CORN GROWN UNDER SALT STRESS CONDITION

A greenhouse experiment was conducted to determine the effect of salinity on the efficacy of two arbuscular mycorrhizal fungi (AMF), Glomus mossea and natural mycorrhiza, of Glomus species, was investigated in terms of growth and nutrition of corn plant (Zea mays L). Plants were grown under different salinity levels imposed by 2.0, 2.5, 3.5, 5.0, 8.0, 12.0 dS m^?1of Hoagland's Solution [sodium chloride (NaCl), sodium sulfate (Na₂SO₄)_, Calcium dichloride (CaCl₂), and magnesium sulfate (MgSO₄) 7:9:3:1 ratio, respectively]. Both types of mycorrhizal fungi did not display significant protection in the host plant against the detrimental effects of the soil salinity. The effect of inoculation on growth varied only with the level of salinity. Maximum root colonization and spore numbers were observed in plants cultivated with low salinity levels. It was found that significant interaction between AMF x Salinity level for calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and manganese (Mn) of shoot, and for Zn and Mn, of root.     

COPPER TOXICITY AND ACCUMULATION IN POTTED SEEDLINGS OF THREE APPLE ROOTSTOCK SPECIES: IMPLICATIONS FOR SAFE FRUIT PRODUCTION ON COPPER-POLLUTED SOILS

A 190-d pot cultivation of three apple rootstock species, Malus hupehensis, M. prunifolia, and M. micromalus, was conducted to investigate tolerance, uptake and accumulation of copper (Cu) in different rootstock species. The calculated soil Cu concentration that reduced plant biomass by 50% decreased in M. hupehensis, M. prunifolia, and M. micromalus. This experiment showed that Cu tolerance of M. hupehensis was superior to the other rootstocks. Copper accumulation proportions in shoots or leaves of M. hupehensis were only 0.7–7.4%, which were the lowest among the three species in both control and Cu treatments, and especially were as low as only 40–50% of those of M. prunifolia. The results indicate that Cu-tolerant low-aboveground-Cu-accumulation rootstocks (i.e., excluder rootstocks) could be a good alternative to produce safe fruits with low Cu concentration on Cu-polluted soils without a complete ban on Cu fungicides.     

ALUMINUM EFFECTS ON GROWTH,PHOTOSYNTHESIS, AND MINERAL NUTRITION OF CACAO GENOTYPES

A solution culture experiment was conducted in a greenhouse with two cacao genotypes (Catongo and Theobahia). Plants were subjected to seven aluminum (Al) concentrations and Al effects on growth, photosynthesis, and mineral content were assessed. Inter-genotypic differences for F_o, F_m and F_v fluorescences, as well as for F_v/F_m, were observed with increasing Al concentrations. There was a decreasing of F_o, F_m, F_v and F_v/F_m for the Catongo. Increasing Al concentration decreased photosynthetic rate, stomatal conductance and leaf transpiration rate, however, inter-genotypic differences in these parameters were not observed. The Al-treatments decreased content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in different plant parts, with the exception of K content in stems of Theobahia and in leaves of both genotypes. Theobahia showed higher tolerance to Al phytotoxicity, manifested mainly in the higher levels of Al in the growth medium. Inter-genotypic differences were observed in the growth and mineral nutrition.     

两广地区不同植被类型与土壤性质的关系

我国热带和亚热带地区幅员辽阔,自然地理条件较为复杂;在热带和亚热带所特有的生物气候因子影响下,土壤向着富铝化的方向进行,造成大面积的红壤、黄壤和砖红壤,后者在广东的南部分布尤广。尽管这些土壤占据着华南相当大的面积,但对其生成发育、特别是发生学上的生物化学过程、植被对土壤性质的影响等方面的研究工作,虽然近年已有论著涉及^[1]。     

淋洗对盐胁迫下大豆生长和矿质营养基因型差异的研究

植物质外体是由细胞壁的纤维素和微晶体空间以及充满空气的细胞间隙组成 ,约占植物体积 5 %的空间。很久以来 ,质外体被认为是无生命的 ,与有生命的原生质相比很少引起研究者的兴趣 ,直到 80年代中期 ,由于研究技术的发展和研究的深入[1 ] ,对质外体的认识才发生根本性的转变 ,     

SOME DELETERIOUS EFFECTS OF LONG-TERM SALT STRESS ON GROWTH,NUTRITION, AND PHYSIOLOGY OF GERBERA (GERBERA JAMESONII L.) AND POTENTIAL INDICATORS OF ITS SALT TOLERANCE

Tolerance of gerbera (Gerbera jamesonii L.) to long-term sodium chloride (NaCl) salt stress was evaluated by subjecting plants to 0, 10, 20, 30 and 40 mM NaCl levels for ten weeks. Increased NaCl led to a significant decrease in leaf and stem biomass. Salt stress significantly affected sodium (Na⁺), potassium (K⁺) concentrations in leaves, stems and roots leading to sharp declines in K⁺/Na⁺ ratios. Magnesium concentrations in stems and roots also showed significant declines. Adverse effect of salt stress on chlorophyll content was also significant. Proline seemed less effective in osmotic adjustment under long-term high salt stress. Switching from vegetative to reproductive growth phase was crucial for certain physiological functions. Leaf Na⁺ concentration showed significant correlation with important traits. These data suggest that NaCl threshold level in irrigation water for gerbera is around 10 mM. Leaf fresh weight, chlorophyll content and leaf K⁺/Na⁺ ratio are promising indicators of salt-sensitivity of gerbera.     

冷诱导基因转录因子CBF1的组成型表达对植物的抗寒性及生长发育的影响

通过农杆菌介导法将玉米泛素启动子(Pubi)调控的CBF1基因以及CaMV35启动子调控的GUS基因一起转化烟草,研究了冷诱导基因的转录因子CBF1(CRT/DRE binding factor 1)对植物抗寒性及生长发育的影响。结果表明:CBF1的组成型表达增强了冷敏感植物的抗寒性;在表型上使植株矮壮,叶片着生密集,叶色深绿,叶厚度增加;促进侧枝生长,延长营养生长期,推迟花期;对植株的结实性无明显影响。植株抗寒能力以及表型变化程度与CBF1的表达强度相关。因此,利用CBF1基因进行植物遗传改良时应根据物种的应用特点采用合适的表达调控策略。     

长期定位施肥对非石灰性潮土粘土矿物组成及主要理化性质的影响

土壤粘土矿物中层状硅酸盐与氧化物共存及晶质和非品质共存。土壤中含钾的粘土矿物主要有水云母、蛭石和绿泥石等。这些粘土矿物影响土壤钾素的固定和释放，进而影响土壤钾的生物有效性。有研究表明，土壤中的层状硅酸盐矿物彼此之间存在着一种相互演变的关系。例如在云母风化初期，通常会出现水化云母，在钾比较丰富的条件下，就会出现伊利石；水化云母进一步风化并释放出更多的钾以后，则形成蛭石和蒙脱石。相反，蛭石和蒙脱石在吸收了钾离子并脱水后，也可以向伊利石及云母类矿物转变。