Analysis of genetic diversity in Piper nigrum L. using RAPD markers

RAPD analysis was conducted in 22 cultivars of P. nigrum(black pepper) from South India and one accession each of P. longum and P. colubrinum. Twenty-four primers generated 372 RAPD markers of which 367 were polymorphic. Jaccard's similarity between pairs of accessions ranged between 0.11 and 0.66 with a mean of 0.38. Among P. nigrum cultivars, the similarity ranged between 0.20 and 0.66 and the mean was 0.42. The existence of wide genetic diversity as revealed in the present study is supported by earlier reports of extensive inter- and intrapopulation morphological variability in pepper cultivars from South India. UPGMA dendrogram and PCO plot revealed P. colubrinum to be most distant of the three species. Genetic proximity among P. nigrum cultivars could be related to their phenotypic similarities or geographical distribution. Greater divergence was observed among landraces than among advanced cultivars. Landraces grown in southern parts of coastal India and those grown in more northern parts were grouped in separate clusters of the dendrogram.     

Effects of biosolarization as methyl bromide alternative for <Emphasis Type="Italic">Meloidogyne incognita</Emphasis> control on quality of soil under pepper

The Adenosine triphosphate (ATP) content, dehydrogenase, phosphatase, urease, and β-glucosidase activity decreased after manure amendment plus solarization (biosolarization), but they recovered after cropping, reaching levels higher than or similar to those before the biosolarization. However, these biochemical parameters decreased and did not recover with time in the methyl bromide (MeBr) treatment. Potential negative soil effects were assayed by measuring, ecotoxicity (Vibrio fisheri luminescence), germination index, electrical conductivity, and heavy metals content. Biosolarization did not negatively affect these parameters, while MeBr application irreversibly decreased the germination index and ecotoxicity. Higher-quality pepper production (extra and first class) were observed with biosolarization but not with MeBr, but no differences were found for pepper yield. Biosolarization gave a Meloidogyne incognita (M. incognita) incidence similar to that of MeBr application.     

Competition for Nitrogen Between Thorn Apple and Tomato and Pepper

The effect of emergence time of the weed Datura stramonium (thorn apple) on tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.) was evaluated in a greenhouse experiment. The closer emergence of the weed was to that of the crops, the greater was the weed's growth, seed production, and nitrogen (N) uptake. As a result, growth, fruit yield, and N uptake of the crops was reduced. Shoot N content was reduced in tomato, as was fruit N content in pepper. There was competition by the weed with the crops for N, even when weed emergence was as late as the beginning of flowering. This competition, and the damage it caused, was always more severe with respect to pepper than tomato, irrespective of weed emergence time. The earlier the emergence of Datura stramonium, the fewer were the number of fruits produced by either crop. Average fresh fruit weight in tomato was also reduced. In pepper, the average fruit weight was reduced only when the weed emerged up to the four-leaf stage of the crop. The drop in pepper fruit yield caused by weed emergence up to the four-leaf stage of the crop could be due to competition for light by the weed, in addition to competition for N. Tomato competed better against the weed than did pepper.     

生物有机肥对田间蔬菜根际土壤中病原菌和功能菌组成的影响

利用实时荧光定量PCR方法对田间条件下连作番茄和辣椒施用生物有机肥(BOF)和常规施肥(CK)的根际土壤微生物中青枯病原菌和功能菌群(固氮菌和荧光假单胞菌)的数量进行定量研究.结果表明:与CK相比,BOF处理的番茄和辣椒产量分别提高了26.0％和19.9％,青枯病发病率分别降低了41.5％和44.7％,番茄和辣椒植株根际土壤固氮菌数量分别增加了23.5％和25.8％、荧光假单胞菌数量分别增加了29.5％和20.2％、病原菌数量分别减少了73.2％和90.1％.生物有机肥能够调控根际微生物区系的组成,降低土传病害的发病率,促进作物健康生长;实时荧光定量PCR方法能够快速准确地检测根际土壤中功能微生物种群数量变化.     

钙盐诱导下土壤锰和铁的释放及其对胡椒的生物有效性

Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO₃)₂ decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P< 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil > albic soil > yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.     

生物质炭介导生防微生物抑制辣椒疫霉的作用

生物质炭可有效防控土传病害,筛选并鉴定出生物质炭介导下的生防微生物,可为研究生物质炭防病机理和强化生物质炭防病效果提供理论依据。本研究首先进行秸秆生物质炭防控辣椒疫病盆栽试验,利用定量PCR和平板计数明确生物质炭在防控辣椒疫病时可富集的已知生防微生物,再通过选择性培养基初筛和定殖复筛筛选出生物质炭可富集的潜在生防微生物菌株,最后研究各菌株在土壤中对辣椒疫霉的抑制作用。结果表明,秸秆生物质炭使根际辣椒疫霉数量显著降低95.1%、辣椒疫病发生率显著降低91.1%,并使具有生防功能的木霉菌、青霉菌、曲霉菌、芽孢杆菌、假单胞菌和鞘氨醇单胞菌数量显著增加2.22倍、4.09倍、3.89倍、2.45倍、1.45倍和1.30倍。通过平板初筛得到可能被生物质炭富集的22株潜在生防菌株。定殖复筛剔除部分假性生物质炭介导菌株,获得可明确被生物质炭富集的2株木霉菌、3株青霉菌、2株曲霉菌、3株芽孢杆菌、3株假单胞菌、3株链霉菌和2株鞘氨醇单胞菌。木霉菌（TR1和TR3）、青霉菌（PE1）、曲霉菌（AS1和AS2）、芽孢杆菌（BA1、BA2和BA3）、假单胞菌（PS1和PS3）、链霉菌（ST1、ST4和ST5）13个菌株可显著削减土壤辣椒疫霉数量。其中,所有木霉菌和曲霉菌菌株（TR1、TR3、AS1和AS2）及芽孢杆菌（BA1和BA2）、假单胞菌（PS1和PS3）和链霉菌（ST1）9个菌株与生物质炭具有显著的协同抑制辣椒疫霉效果。因此,防控辣椒疫病时,木霉菌、曲霉菌、芽孢杆菌、假单胞菌和链霉菌是生物质炭介导下的主要防病微生物。     

不同辣椒品种混种根系互作对产量及根际氮转化的影响

以不同辣椒品种薄皮椒(Capsicum annuum)、线椒(Capsicum frutescens)为试验材料,采用盆栽方式,通过分析同种种植或混种(交叉及同行)模式下两种辣椒的产量、生物量、氮素积累量及根际土中氮形态和含量的变化,探究同种或混种辣椒根系互作对氮吸收积累的影响.结果表明,两种辣椒混合种植的果期茎叶干物...     

Olfactory response of Myzus persicae (Homoptera: Aphididae) to volatiles from leek and chive: Potential for intercropping with sweet pepper

Abstract

Odour-mediated effects of leek Allium porum and chives Allium schoenoprasum (Alliaceae) on the host searching behaviour of the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) were studied. In an olfactometer, odour of the host plant sweet pepper Capsicum annuum L. (Solanaceae) was significantly attractive, whereas odour of chives was significantly repellent. Combined odour of sweet pepper and chives was neither attractive nor repellent. When sweet pepper plants were exposed to volatiles from chives for five days, their odour subsequently became repellent to M. persicae. An extract of leek plants was significantly repellent to aphids in the olfactometer, as were sweet pepper plants sprayed with this extract. Because both leek and chives can disrupt host finding by the aphid, both plants have potential for intercropping with sweet pepper. If successful in the field, such a system could bring economic benefits for farmers in the wet zone of Sri Lanka and other parts of the world.     

Effects of different mulching practices on the photosynthetic characteristics of hot pepper (Capsicum annuum L.) in a greenhouse in Northwest China

Mulching is considered a desirable management technology for improving and stabilizing agricultural crop production. The aim of the present study was to evaluate the effect of different mulching practices on hot pepper (Capsicum annuum L.) performance in terms of leaf photosynthetic capacity, photosynthetic light response (PLR) curves, and growth parameters, under greenhouse conditions. Consequently, field experiments were conducted during the 2011 and 2012 growing seasons in Northwest China using four types of mulching practices (without mulch; wheat straw mulch; plastic film mulch; and combined mulch with plastic film and wheat straw). The results showed that mulching increased the leaf net photosynthesis rate, stomatal conductance to water vapor, intercellular CO₂ concentration, water-use efficiency, and transpiration rate. Mulching significantly affected the PLR curves, and important parameters (such as the apparent quantum yield, maximum net photosynthetic rate, light compensation point, and light saturation point) were all improved under combined mulching conditions when compared with other mulching practices. Therefore, it is inferred that hot pepper leaf photosynthetic capacity and light-use efficiency were significantly improved under combined mulching, and thereby the combined mulching is recommended for hot pepper cultivation in greenhouses due to working well to facilitate soil condition (moisture and temperature), plant growth, and marketable photosynthetic characteristics.     

Losses in Nitrogen Uptake by Tomato and Pepper Due to Infestation by the Weed Barnyardgrass

Abstract

Glasshouse experiments showed that the weed “barnyardgrass” (Echinochloa crus‐galli) competes for nitrogen (N) with tomato and pepper crops. Competition was more severe with pepper than with tomato, and greater in both crops the earlier the weed emerged or the longer it grew with the crops. This competition affected growth attributes, fruit yield and its components, and N uptake in both crops. Shoot N content was also affected in pepper. Significant damage to both crops occurred even when weed emergence was as late in the crop growth season as the beginning of flowering.     

Powdery Mildew Resistance in a Collection of Chinese Barley Varieties

One hundred and forty-seven Chinese barley varieties maintained at the Gene Bank of the National Barley Improvement Centre, Zhejiang, and 84 progenies from these varieties were tested at the seedling stage for their reaction to 32 selected pathotypes of Blumeria graminis f. sp. hordei. Eighteen resistance spectra were identified comprising single or combined resistances from eight known (Ml(Bw), Ml(Ch), Mla7, Mla8, Mla9, Mla13, MlaRu4 and Mlg) and six unknown resistance genes. The most frequent gene was Ml(Bw), which was found in 69 varieties and previously detected in only a few European winter barley varieties. The genes Mla8 and Ml(Ch) were also often present, but other resistance genes were rare. After inoculation, considerably fewer pathogen colonies were observed in ‘Aiganqi’ and one line of ‘Tong5’. Twenty varieties were composed of lines with different resistance genes. China is likely to be a region of origin of the genes Ml(Bw), Mla7, as well as three unknown genes found in original landraces and perhaps another three unknown genes detected in cultivars bred in China. The resistances of varieties from the Zhejiang province and those originating from 11 other Chinese provinces were quite different. Unfortunately, none of the varieties are promising sources of resistance to powdery mildew and China does not seem to be a region suitable for identifying such sources.     

RAPD and AFLP assessment of genetic variation in a landrace of pepper (Capsicum annuum L.), grown in North-West Italy

In several regions of Italy as well as other parts of southern Europe, the heterogeneity of the land, the climate and the soil favour the survival in cultivation of a large number of landraces specifically adapted to local conditions. Knowledge on the level and distribution of their genetic variation can help to develop appropriate strategies, in order to suistainably manage in situ these germplasm resources at risk of genetic erosion. C. annuum is an herbaceous diploid species and is considered to be self-pollinating, although different rates of out-crossing have been recorded. We used random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers to assess genetic diversity within and between five populations of a landrace of Capsicum annuum L., grown in a limited area in north-west Italy and locally known as Cuneo pepper. Partitioning the genetic variation with Shannon's diversity index revealed that 41.6% occurred between and 58.4% within populations. Analogous results were obtained when the analysis was based only on RAPD or AFLP markers. However, AFLP was more reliable, since a lower range of variation was observed among primer combinations in detecting the two components of genetic variation. Notwithstanding the rather high level of within genetic variation detected, the five populations were clearly differentiated and differed in the frequency of alleles exclusive and/or present at very low frequencies. Our results show the need for accurate estimation of allele frequencies, in order to identify populations to which priority should be given for dynamic conservation of landraces.     

Use of GIS for Optimizing a Collecting Mission for a Rare Wild Pepper (<Emphasis Type="Italic">Capsicum flexuosum</Emphasis> Sendtn.) in Paraguay

This paper presents an effective method for prioritizing areas within a country for acquisition of germplasm of a crop gene pool for ex situ conservation. The method was applied to the rare wild pepper species, Capsicum flexuosum Sendtn., in south-east Paraguay. A model to prioritize areas for collecting germplasm was constructed by combining (1) a prediction of the species' geographic distribution based on the climate at previous collection points, (2) the distribution of forest margins (the species' natural habitat) and (3) areas accessible by road. The model was then tested in the field by visiting 20 sites having both high and low predicted probability of occurrence of C. flexuosum. Six new populations were found, representing a significant improvement over two previous collecting missions for the species in the same region, undertaken without the use of GIS targeting. Using the most optimistic analysis of model performance, C. flexuosum was found at five out of seven points predicted to harbour the species and not found at four of five points predicted not to harbour the species. The model was then improved by the use of higher resolution climate surfaces. It is recommended that future explorers use more recent and higher resolution satellite images to locate suitable habitats. The method is replicable for different species in different geographic regions and is offered as a means of optimizing efficiency in financially constrained, national plant genetic resources programs.     

Effect of Pseudomonas putida and inorganic fertilizer on growth and productivity of habanero pepper (Capsicum Chinense Jacq.) in greenhouse

The habanero pepper is widely used in a variety of commercial food products. The increase in the cultivation area of the habanero pepper has increased the use of agricultural inputs, mainly inorganic fertilizers, which have high economic costs and cause negative effects to the soil and water. In recent years, the use of beneficial soil microorganisms has been studied as an alternative to inorganic fertilizers. In the present study, the effect of three strains of Pseudomonas putida on the growth and productivity of King Pakal hybrid habanero pepper with limited inorganic fertilizer in a greenhouse. It was found that a reduction of inorganic fertilizer application of 25% with P. putida rhizobacteria strains increased or maintained growth and productivity of King Pakal hybrid habanero pepper. Before these rhizobacteria can be used in the field, results will first need to be confirmed under more natural conditions.     

喀斯特槽谷区不同林草恢复模式下土壤入渗特征

为研究不同林草恢复模式对喀斯特槽谷区坡面的水土保持效应,采用野外调查和室内分析相结合的方法,对比分析了喀斯特槽谷区顺、逆向坡面不同林草模式(林地、花椒地、灌草地)下的土壤理化性质和入渗特征。结果表明:(1)顺、逆向坡面下林地容重最小,孔隙度最好,含水率和有机质含量最高,其次是花椒地和灌草地;顺向坡土壤有机质含量显著高于逆向坡(P<0.05),但其他理化指标间差异不显著(P>0.05)。(2)顺、逆向坡面下花椒地入渗曲线较陡峭,而林地、灌草地相对较缓;灌草地入渗率最先趋于稳定(20min左右),而花椒地和林地入渗率在30min左右开始缓慢下降,直到75min以后渐渐趋于稳定;各林草恢复模式下土壤入渗能力均为林地>花椒地>灌草地(P<0.05)。(3)入渗模型中,Horton模型拟合效果最好(R2>0.712),模拟稳定入渗率与实测值间的回归方程决定系数R2高达0.9789。(4)研究区土壤稳定入渗率与总孔隙度、非毛管孔隙度、饱和含水量及pH均呈正相关,而与有机质呈负相关,其中总孔隙度对土壤入渗性能影响最大,有机质影响最小;利用上述指标建立的多元线性回归方程可精确预测土壤稳定入渗率。研究结果可为喀斯特槽谷区坡面植被恢复选择及土壤入渗性能评估提供理论参考。     

叶面喷施含Bacillus amyloliquefaciens SQR9 复合微生物液体肥料的肥效研究

研究叶面喷施含BacillusamyloliquefaciensSQR9复合微生物液体肥料在辣椒和白菜上的应用效果,以期开发出根际有益微生物新的应用模式和新的叶面肥产品。以辣椒和白菜为供试材料,设以下6个处理评估肥料效果:喷施清水处理(CK)、喷施与复合微生物液体肥料等养分的化肥处理(CF)、喷施含化肥+氨基酸+糖蜜的水溶肥处理(T1)、喷施含化肥+氨基酸+糖蜜+微量元素的水溶肥处理(T2)、喷施含化肥+氨基酸+糖蜜+SQR9的水溶肥处理(T3)和喷施含化肥+氨基酸+糖蜜+微量元素+SQR9的复合微生物液体肥料处理(T4)。盆栽试验结果表明,与其他5个处理(CK、CF、T1、T2、T3)相比,T4处理在各项促生指标上虽未全部达到显著性差异,但其更能够促进辣椒和白菜的生长,提高其生物学性状。可培养微生物数量上,新型含菌株SQR9复合微生物液体肥料的喷施,增加了叶际芽孢杆菌的数量;与喷施清水对照(CK)和与复合微生物液体肥料等养分的化肥处理(CF)相比,其他4个处理(T1、T2、T3、T4)对辣椒和白菜叶际可培养微生物数量影响更大,而喷施含Bacillus amyloliquefaciens SQR9复合微生物液体肥料(T4)的影响更为明显。叶面喷施含Bacillus amyloliquefaciens SQR9复合微生物液体肥料可有效促进辣椒和白菜的生长。     

Plant growth and fruit quality of two pepper cultivars under different potassium levels of nutrient solutions

Potassium (K) is a major nutrient element that has effects on growth, yield, and quality production of agricultural crops. In the present study, the effects of various K concentrations in a nutrient solution including 150, 235, 300, 400, or 500 mg K L^?1 were evaluated on two pepper cultivars; chili pepper (Capsicum annuum Avicolare) and bell pepper (California Wonder) under greenhouse conditions. Hoagland's formula was used for preparation of nutrient solutions. The vegetative growth parameters including plant height, leaf area, SPAD value, and shoot fresh weight were significantly increased by 300 mg L^?1 K in both cultivars. The highest yield and fruit quality parameters including fruit length/diameter ratio, fruit dry matter percentage, fruit vitamin C, total soluble solids, and titratable acidity in chili pepper and bell pepper were obtained under application of 300 and 400 mg K L^?1 in nutrient solution, respectively. In either cultivar there was increase in leaf K, nitrogen, and zinc concentrations, while in bell pepper calcium was reduced by higher K levels in the nutrient solution. The results indicate that for better growth and quality production of pepper, higher levels of K in nutrient solutions can be beneficial.     

The Distribution of <Emphasis Type="Italic">Perilla</Emphasis> Species

Perilla (Lamiaceae) contains one tetraploid species, P. frutescens (L.) Britt. and three diploid species, P. citriodora (Makino) Nakai, P. hirtella Nakai and P. setoyensis G. Honda. Tetraploid species have been traditionally cultivated in Asia for their seed oil and for their fragrant leaves that are used as medicine or as a garnish for fish. The center of diversity is still obscure. To conserve the genetic resources, it is important to know the diversity of the tetraploid species. The three diploid species, which are possible parents of the tetraploid species, are all believed to be indigenous to Japan. Their distribution in China and Korea was clarified on the basis of herbarium and field surveys. The tetraploid species is assumed to have originated somewhere around the mid-to downstream area of the Changjiang River. Though Perilla is not cultivated as often in these areas as in northern China, Korea, the Himalayan region, or Myanmar, these areas should also be important for the conservation of genetic resources of tetraploid Perilla crops because of the expected high genetic diversity.     

烟粉虱取食对不同抗虫性辣椒品种营养物质和抗性物质的影响

为了探讨烟粉虱取食对辣椒体内营养物质和抗性物质的影响,选择抗虫辣椒品种(‘新一代三鹰椒’、‘新苏椒五号’)和感虫品种(‘苏椒13号’、‘苏椒15号’)各2个,每株辣椒分别接烟粉虱成虫0头(对照)、30头(低密度)、60头(中密度)和120头(高密度),取食24 h后测定辣椒叶片中叶绿素、可溶性糖、可溶性蛋白以及酚类、黄酮类化合物含量。结果发现,低密度的烟粉虱取食后,辣椒叶片叶绿素含量显著上升,随着虫口密度的提高,叶绿素含量有所下降,但仍高于对照;感虫辣椒品种的叶绿素含量增加幅度高于抗虫品种。低密度和高密度的烟粉虱取食后,辣椒叶片中可溶性糖含量出现明显下降趋势,抗虫品种的下降幅度大于感虫品种。低密度和中密度的烟粉虱取食后,辣椒叶片中可溶性蛋白含量显著下降,但高密度烟粉虱取食后辣椒叶片中可溶性蛋白含量明显上升;抗虫品种的变化幅度明显高于感虫品种。烟粉虱取食后,叶片中酚类化合物含量明显上升,感虫品种的上升幅度较抗虫品种上升幅度大;随着虫量的增加,辣椒叶片中酚类化合物含量呈明显上升趋势,但高密度烟粉虱取食后酚类化合物含量出现明显下降趋势。烟粉虱取食后,感虫辣椒品种‘苏椒15号’叶片中黄酮类化合物含量明显上升;其他3个品种在中等以下密度的烟粉虱取食时,黄酮类化合物与对照差异不显著,但在高密度烟粉虱取食时,黄酮类化合物明显高于对照。研究表明,烟粉虱取食可引起辣椒营养物质和抗性物质含量向着有利于提高抗虫性的方向改变,但不同虫口密度下不同辣椒品种的改变幅度不同。研究结果为进一步揭示寄主植物与烟粉虱之间的防御和反防御机制提供了基础。     

Effects of humic acid and Ca(NO3)2 on nutrient contents in pepper (Capsicum annuum) seedling under salt stress

This study was carried out in order to determine the effects of calcium nitrate (Ca(NO₃)₂) and humic acid (HA) applications on nutrient uptake of pepper seedling under salt stress in a plant growth room. Before sowing Demre variety of pepper seeds, 60?mM NaCI was added to each 300?cm³ pot. The experiment was ended at eighth week after the sowing. Applications of HA significantly affected K, Ca, Fe, Mn, Zn (p?p?3)₂ applications did not show a significant effect on Fe and Cu contents of pepper seedling. However, Ca(NO₃)₂ applications significantly affected N and P contents (p?<.05) and K, Ca, Mn, and Zn contents (p?相似文献