Improving the Drought Tolerance in Pistachio (Pistacia vera) Seedlings by Foliar Application of Salicylic Acid

Gesunde Pflanzen - Pistachio (Pistacia vera L.) is an economically important nut crop that is prone to drought stress since it is mainly produced in arid and semi-arid regions. Considering...     

GC/MS法分析囊果碱蓬种子油中脂肪酸组成

用溶剂萃取法获得新疆产囊果碱蓬植物种子油,得油率27.09%.甲酯化后用GC/MS分析其中的脂肪酸组成及其相对含量.检出10种脂肪酸,归一化结果表明:不饱和脂肪酸占95.98%,其中亚油酸占75.40%,油酸占13.09%,α γ亚麻酸占5.70%,棕榈酸占3.88%.     

The Fatty Acid Composition of Plasmopara halstedii and Its Taxonomic Significance

The fatty acid composition of sunflower downy mildew, Plasmopara halstedii, was compared to other parasitic Oomycetes and to pathogenic fungi associated with sunflower by gas chromatographic analysis. P. halstedii revealed a characteristic profile differing from all other samples by the dominance of 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acid. The infraspecific variation between the isolates of sunflower downy mildew was low: no correlation was visible between fatty acid profiles and isolates of different pathotypes or from different geographic origins. Lipids from hyphae, zoosporangia and oospores of the pathogen contained the same fatty acids, though the content of 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acid was significantly lower in oospores. The taxonomic and diagnostic value of the fatty acid profile in P. halstedii is discussed.     

Grain Yield and Qualitative of Rapeseed Genotypes Change in Response to Exogenous Application of Salicylic Acid and Planting Density

Gesunde Pflanzen - A factorial split-plot experiment (2015–17) was carried out in a randomized complete block design with three replications at Karaj, Iran, to investigate...     

干旱区蓖麻生长发育及N、P、K累积规律

为促进蓖麻在西北绿洲灌溉区的推广种植和产量提高,以农风牌蓖麻杂交种作为试验材料,采用田间试验方法,对蓖麻不同生育期各器官干物质累积量和养分含量(N、P、K)进行了研究,同时记录蓖麻各生育期的有效积温,以探讨蓖麻在干旱灌区的生长发育和养分累积规律。结果表明:蓖麻各器官的干物质积累速率均呈慢-快-慢的变化趋势,但峰值的出现时间因器官不同而有所差异,其中,营养器官的干物质积累速率在花期最大,穗在果期;而且从果期开始,蓖麻穗部干物质净积累量的分配率逐渐高于营养器官,并在灌浆期达到顶峰(80%以上)。氮素在蓖麻体内的累积主要在灌浆期前,但磷素的累积到灌浆期仍能保持在很高的水平,而且这一时期蓖麻茎叶中的大量磷、钾素会转运至穗部。此外,蓖麻主穗和一级穗从现蕾到灌浆成熟均需要58 d,所需≥10℃的有效积温分别为924℃和888℃。蓖麻的生长发育及需肥规律表现出一致的趋势,高峰期均在花果期,此时应加强对肥料的管理,在生长发育中后期要特别注意磷、钾肥的追施。     

球孢白僵菌脂肪酸、酯酶、脂肪酶及其与毒力的关系

研究12株球孢白僵菌脂肪酸、酯酶和脂肪酶的产生水平及菌株对马尾松毛虫毒力间的关系。结果表明：酯酶产生水平（E）、脂肪酶产生水平（L）及豆蔻酸百分含量（X）等与白僵菌菌株对马尾松毛虫的毒力（LT50）间存在一定的相关性，其相关方程分别为：LT50=2．0931/（lgE-5．1165）＋0．4091；LT50=-6．68L^2＋31．9886L；LT50=13．5192-8．7042X。     

Liquid Swine Manure Can Kill Verticillium dahliae Microsclerotia in Soil by Volatile Fatty Acid, Nitrous Acid, and Ammonia Toxicity

ABSTRACT In previous studies, liquid swine manure (LSM) was sometimes shown to reduce Verticillium wilt of potato caused by Verticillium dahliae. We also observed that microsclerotia of this fungus died within 1 day, or between 3 and 6 weeks, after addition of LSM to some acid soils and within 1 week in some alkaline soils. In this study, we demonstrated that a volatile fatty acid (VFA) mixture with an identical concentration of VFAs as that found in an effective LSM reduced germination in an acid soil (pH 5.1) to the same extent as the LSM after 1 day of exposure. Germination was reduced by 45, 75, and 90% in the 10, 20, and 40% ([wt/wt] soil moisture) treatments, respectively, with the latter being equivalent to an application of 80 hl/ha. Addition to this acid soil of 19 LSMs (30% [wt/wt] soil moisture) collected from different producers resulted in complete kill of microsclerotia with 12 manures. Effective manures had a total concentration of nonionized forms of VFAs in soil solution of 2.7 mM or higher. In some acid soils (pH 5.8), addition of LSM (40% [wt/wt] soil moisture) did not kill microsclerotia until 3 to 6 weeks later. Here, a reduction in viability of microsclerotia was attributed to the accumulation of 0.06 mM nitrous acid in the soil solution at 4 weeks. When an LSM was added (40% [wt/wt] soil moisture) to an alkaline soil (pH 7.9) where VFAs are not toxic, microsclerotia germination was reduced by 80% after 1 week. Here the pH increased to 8.9 and the concentration of ammonia reached 30 mM in the soil solution. An ammonium chloride solution having an equivalent concentration of ammonium as the manure was shown to have the same spectrum of toxicity as the manure in assays ranging from pH 7 to 9, both in solutions and above the solutions. At pH 9, the concentration of ammonia reached 18 mM and 100% mortality of microsclerotia occurred. Thus, in acid soils, LSM can kill microsclerotia of V. dahliae by VFA and/or nitrous acid toxicity and in alkaline soils by ammonia toxicity. In order to take advantage of these mechanisms for disease reduction, the manure chemical composition, rate of addition, and soil characteristics need to be determined for each instance of use.     

Whole-Cell Fatty Acid Composition to Characterize and Differentiate Isolates of Rhizoctonia Species Associated with Turfgrass Diseases in Japan

Cellular fatty acids were analyzed to characterize and differentiate 34 isolates of Rhizoctonia species representing binucleate Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB, AG 2-2 LP, R. circinata var. circinata and var. oryzae associated with turfgrass diseases in Japan. Myristic, pentadecanoic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acids were consistently present in varying quantities in all isolates. Heptadecanoic and 9-heptadecenoic acids were present in isolates of Rhizoctonia AG-D (I), AG-D (II), R. solani AG 2-2 IIIB and AG 2-2 LP but not in isolates of R. circinata var. circinata and var. oryzae. Palmitic, oleic and linoleic acids were the major fatty acids found, constituting 88.30-98.37% of the whole-cell fatty acid content. The remaining fatty acids were present in smaller amounts. Isolates within a single group were closely clustered, whereas isolates from different groups were clearly distinguishable based on average linkage cluster analysis of cellular fatty acids. Principal component analysis, based on all fatty acids detected, confirmed the distinct separation of isolates representing the six groups of Rhizoctonia species obtained from turfgrasses. These results suggested that fatty acid analysis is useful for the characterization and differentiation of isolates of Rhizoctonia species associated with turfgrass diseases. Received 21 May 2001/ Accepted in revised form 28 September 2001     

新疆霍城县大、小西沟野果林种子植物组成及资源

新疆伊犁霍城大、小西沟野果林是以野樱桃李群落为主的野果林,共有种子植物60科233属500余种.林区野生植物资源丰富,统计表明:有野生果树38种、食用植物30种、饲用植物60种、蜜源植物111种、观赏植物128种、香料植物50种、药用植物113种.其中包括国家重点保护植物9种;新疆维吾尔自治区重点保护植物9种;中国珍稀濒危保护植物3种.通过多次实地调查分析,阐明了霍城野果林野生果树的分布、繁衍规律和植被、生境状况;综述了植物资源类型和用途及野生樱桃李群系生存的濒危程度.并提出在霍城大、小西沟野樱桃李集中分布区建立自然保护区的建议.     

Growth, Yield and Blossom-End Rot Incidence in Bell Pepper as Affected by Phosphorus Level and Amino Acid Applications

This study was conducted to examine the possibility of enhancing productivity and reducing blossom-end rot (BER) incidence in bell pepper (Capsicum annumn L.). Four rates of phosphorus application (30, 60, 90 and 120?kg?ha^{? 1} of P₂O₅) were combined with two commercial naturally occurring amino acid stimulants (Amino green and Aminofort). Water was used as a control treatment as well. Plants were sprayed with 500?ppm of solutions three weeks after transplanting. Increasing P application rate increased vegetative growth, fruit yield, fruit quality (fruit size, TSS, acidity and vitamin C.) and nutritional elements content (N, P, K and Ca). However, it was showed that the phosphorus level of 90?kg?ha^{? 1} had no significant differences to the level of 120?kg?ha^{? 1} for most parameters measured. Furthermore, P-applications had a remarkable effect on reducing blossom end rot, probably due to a positive effect on water uptake and Ca acquisition. In addition, positive effects on the vegetative growth parameters, individual fruit weight and number of fruits were showed concerning the amino acid used. Fruit quality in terms of total soluble solids (TSS), total acidity and ascorbic acid contents were also improved compared to control. Aminofort was superior in its effect as Amino green. However, the tested amino acids showed no effect on BER incidence.     

Attenuation of Negative Effects of Saline Stress in two Lettuce Cultivars by Salicylic Acid and Glycine Betaine

Reducing destructive effects of lettuce plants irrigated with saline water was investigated in two field experiments conducted at Ismailia Governorate in 2012–2013 and 2013–2014. Two lettuce (Lactuca sativa L.) cultivars, Great Lakes and Balady, irrigated with saline water (3.22 dS/m) were treated using two levels of salicylic acid (SA) and glycine betaine (GB) as a foliar application (200, 400 ppm and 15, 30 Mm, respectively). Generally, application of SA and GB enhanced growth parameters, i.?e. plant height; root length; number of leaves per plant; plant fresh and dry weight; leaf relative water content (LRWC); membrane permeability (MP); lipid peroxidation (MDA); chlorophyll a, b and carotenoid content in leaf; proline; total soluble sugars (TSS); superoxide dismutase (SOD) and peroxidase (POD) activity; and Na, K, Ca content. GB treatments significantly increased most recorded growth parameters, especially at 30 mM, while this treatment decreased values of MP, (MDA) and Na content in two lettuce cultivars.     

Impact of Exogenous Application of Salicylic Acid on Growth,Water Status And Antioxidant Enzyme Activity of Strawberry Plants (Fragaria vesca L.) Under Salt Stress Conditions

Irrigation with saline water can act as an alternate water resource and thus plays an important role in saving freshwater resources as well as promoting agriculture. Furthermore, salinity stress is considered one of the major abiotic stress factors, which strongly reduces crop productivity. In this context, the present work was conducted to examine the effect of exogenous salicylic acid (SA) application on salt stress tolerance of strawberry plants. For this purpose, strawberry plants (Fragaria vesca L.), three months old, were treated with three SA concentrations (0?mM, 0.25?mM and 0.5?mM), then subjected to 80?mM NaCl or not. After five weeks of treatment, growth responses, water status, photochemical efficiency and oxidative stress indicators were measured. The obtained results showed that irrigation with saline water negatively affected the growth parameters, the leaf water potential (LWP), the relative water content (RWC), the stomatal conductance (gs) and photochemical efficiency (Fv/Fm). While, the total protein content, the electrolyte leakage (EL), the malondialdehyde (MDA) and the hydrogen peroxide (H₂O₂) contents were increased in stressed plants compared to unstressed ones. Salt stress also leads to the activation of the antioxidant enzymes. However, the exogenous application of SA under salt stress conditions reduced the H₂O₂ accumulation, the electrolyte leakage and the MDA content. It has also improved the growth parameters, the LWP, the RWC, the gs, the Fv/Fm, the protein content and the antioxidant enzyme activities (POD, CAT and SOD) in the treated plants compared to those without SA application. Therefore, the beneficial effect of 0.25?mM SA on Fragaria vesca L. salinity tolerance may provide some practical basis for strawberry cultivation under saline conditions.

     

PEG6000模拟干旱胁迫对铃铛刺和披针叶野决明种子萌发的影响

水是种子萌发的关键因素,种子萌发及幼苗生长直接影响着干旱区植被的分布和多样性。以铃铛刺(Halimodendron halodendron)和披针叶野决明(Thermopsis lanceolata)种子为研究材料,用不同浓度PEG6000模拟干旱胁迫,探讨干旱胁迫对铃铛刺和披针叶野决明种子萌发的影响。结果表明:不同浓度处理均降低了铃铛刺和披针叶野决明种子的发芽率、发芽势、日相对发芽率和平均发芽速率,延缓了种子萌发进程,胚芽和胚根生长也受到抑制。不同浓度处理中,12%是相对高萌发率的浓度,其种子的发芽率、发芽势、日相对发芽率、平均发芽速率、胚根及胚芽长均明显高于其他处理,与对照相近。干旱胁迫对铃铛刺和披针叶野决明种子萌发影响不完全一样,如对胚芽和胚根生长的抑制作用,铃铛刺种子胚芽和胚根作用相近,披针叶野决明则对胚根作用较胚芽明显。     

Transmissibility of Cucumber mosaic virus by Aphis gossypii Correlates with Viral Accumulation and Is Affected by the Presence of Its Satellite RNA

ABSTRACT Satellite RNAs (satRNAs) are associated with Cucumber mosaic virus (CMV) in tomato, most often causing severe epidemics of necrotic plants, and not associated with specific host symptoms. Laboratory studies on virus transmission by the aphid vector Aphis gossypii were performed to better understand the dynamics of field populations of CMV. The presence of satRNAs correlated with lower concentrations of virus in infected plants and with a decrease in the efficiency of transmission from satRNA-infected plants. Both the concentration of virus in CMV-infected tomato and the efficiency of transmission varied more extensively with nonnecrogenic satRNAs than with necrogenic satRNAs. A negative effect of satRNAs on virus accumulation can account, in part, for a decrease in the field transmission and recovery of CMV + satRNAs. Aphids behaved differently and probed less readily on plants infected with CMV + necrogenic satRNAs compared with plants containing non-necrogenic satRNAs. Aphid-mediated satRNA-free CMV infections were observed in test plants when aphids were fed on source plants containing CMV + nonnecrogenic satRNA; no comparable satRNA-free test plants occurred when aphids were fed on source plants containing necrogenic satRNAs. These results indicate that factors associated with transmission can be a determinant in the evolution of natural populations of CMV and its satRNA.     

Infection of Commercial Hybrid Primula Seed by Botrytis cinerea and Latent Disease Spread Through the Plants

ABSTRACT Botrytis cinerea occurred commonly on cultivated Primula xpolyantha seed. The fungus was mostly on the outside of the seed but sometimes was present within the seed. The fungus frequently caused disease at maturity in plants grown from the seed, demonstrated by growing plants in a filtered airflow, isolated from other possible sources of infection. Young, commercially produced P. xpolyantha plants frequently had symptomless B. cinerea infections spread throughout the plants for up to 3 months, with symptoms appearing only at flowering. Single genetic individuals of B. cinerea, as determined by DNA fingerprinting, often were dispersed widely throughout an apparently healthy plant. Plants could, however, contain more than one isolate.     

Identification and Characterisation of Xanthomonas campestris pv. campestris Strains from Tanzania by Pathogenicity Tests, Biolog, rep-PCR and Fatty Acid Methyl Ester Analysis

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), is a major disease constraint to cabbage production by smallholder farmers in Africa. Variability exists within the pathogen, and yet differentiation of Xcc strains from other closely-related xanthomonads attacking crucifers is often difficult. The Biolog system, fatty acid methyl ester analysis using microbial identification system (MIS), rep-PCR and pathogenicity tests were used to identify and characterise Xcc strains from Tanzania. Great diversity was observed among Xcc strains in their Biolog and rep-PCR profiles. Specific rep-PCR genomic fingerprints were linked to some geographical areas in the country. Most of the Xcc strains were clustered in two groups based on their fatty acid profiles and symptom expression in cabbage although some deviant strains were found. Each of the methods allowed a degree of identification from species, pathovar to the strain level. Biolog and MIS identified all Xcc strains at least to the genus level. Additionally, Biolog identified 47% of Xcc strains to the pathovar and 43% to strain level, whereas MIS identified 43% of the strains to pathovar level. In the absence of a database, the utility of rep-PCR for routine diagnosis of strains was limited, although the procedure was good for delineation of Xcc to the strain level. These findings indicate the existence of Xcc strains in Tanzania that are distinct from those included in Biolog and MIS databases. The limitations noticed warrant continued improvement of databases and inclusion of pathogenicity testing, using universally susceptible cultivars, as an integral part of strain identification.     

Sporulation of Bremia lactucae Affected by Temperature, Relative Humidity, and Wind in Controlled Conditions

ABSTRACT The effects of temperature (5 to 25 degrees C), relative humidity (81 to 100%), wind speed (0 to 1.0 m s(-1)), and their interactions on sporulation of Bremia lactucae on lettuce cotyledons were investigated in controlled conditions. Sporulation was affected significantly (P < 0.0001) by temperature, with an optimum at 15 degrees C, and by relative humidity (RH), with sporulation increasing markedly at RH >/= 90%. There was a significant effect of exposure time in relation to temperature (P = 0.0007) but not to RH. In separate experiments, both RH and wind speed significantly (P < 0.0001) affected the number of cotyledons with sporulation and the number of sporangia produced per cotyledon. No sporulation was observed at wind speeds of >0.5 m s(-1), regardless of RH. In still air, the number of sporangiophores produced per cotyledon increased linearly with RH from 81 to 100% (P = 0.0001, r = 0.98). Histological observations indicated that sporulation may be affected by stomatal aperture in response to RH, as more closed stomata and correspondingly fewer sporangiophores were present at lower RH. These results are important for understanding the mechanism of RH effects on sporulation and for predicting conditions conducive to downy mildew development.     

Effects of Two Triazole Seed Treatments,Triticonazole and Triadimenol,on Growth and Development of Wheat

The triazole fungicides, triadimenol and triticonazole, applied as seed treatments at various rates on spring wheat, affected plant growth, shoot development, and root axis production. The main growth regulatory effects were reductions in lengths of the coleoptile, the first leaf and the subcrown internode. A marked effect on tiller appearance occurred with high rates of triadimenol. Modification of root-system development included a reduction in the number of seminal roots, increased outgrowth of roots associated with the coleoptilar node, and a reduction of roots at the first foliar node (correlated with reduced production of Tiller 1). Seed treatment effects on both shoot and root development illustrated the close relationship between these plant structures. Both fungicides induced both beneficial and deleterious effects on wheat growth and development, but the magnitude of deleterious effects was less with triticonazole than with triadimenol.