尖叶木樨榄作砧木嫁接油橄榄的研究

本文就云南、四川两省采用尖叶木樨榄(Olea ferrugineaRoyle.)作砧木嫁接油橄榄(Olea europaea L.)二十余年的试验观察,报道尖叶木樨榄在我国的分布及其生物学特性,系统总结尖叶木樨榄作砧木对油橄榄生长发育及开花结实的影响。试验结果表明:尖叶木樨榄作砧木具有种子出苗率高,嫁接繁殖容易,提早油橄榄开花结实年龄,增强油橄榄对酸性红壤的适应性,增强油橄榄对干旱环境和对某些病害的抗性等优点。此砧木已在我国西南部油橄榄适生区应用于生产性栽培。     

Symptom-based diagnosis of Huanglongbing (citrus greening) disease by PCR in sweet orange (Citrus sinensis Osbeck) and acid lime (Citrus aurantifolia Swingle)

Huanglongbing (HLB), previously known as citrus greening disease, is one of the most destructive diseases of citrus and responsible for the decline of citrus orchards in Andhra Pradesh (AP) and other citrus growing areas in the country. Polymerase chain reaction (PCR) amplification of 1160 bp fragment of 16S rDNA of HLB was observed in mottling symptoms, yellow vein symptoms, symptoms mixed with both citrus yellow mosaic virus and citrus greening and zinc deficiency-like symptoms; however, no amplification was observed in iron deficiency like symptoms. As the disease shows a variety of symptoms in infected trees, PCR detection could be useful for resolving confusion in identification of HLB between actual deficiency and deficiency like symptoms caused by HLB. In acid lime the midrib and veins of the leaves with both mottling and yellow vein symptoms were suitable for isolation of DNA and used as a template in the PCR test.     

Detection and Identification of Aster Yellows (16SrI) Phytoplasma in Peach Trees in Jordan by RFLP Analysis of PCR-Amplified Products (16S rDNAs)

Aster yellows phytoplasma were detected, for the first time, in peach trees in Al‐Jubiha and Homret Al‐Sahen area. Leaves of infected trees showed yellow or reddish, irregular water‐soaked blotches. Discoloured areas become dry and brittle and the dead tissues dropped out. Under severe infections, leaves fall down and fruits dropped prematurely. Phytoplasmas were detected from all symptomatic peach trees by polymerase chain reaction (PCR) using universal phytoplasmas primers P1/P7 followed by R16F2/R2. No amplification products were obtained from templates of asymptomatic peaches. PCR products (1.2 kb) used for restriction fragment length polymorphism analysis (RFLP) after digestion with endonuclease AluI, HpaII, KpnI and RsaI produced the same restriction profiles for all samples, and they were identical with those of American aster yellows (16SrI) phytoplasma strain. This paper is the first report on aster yellows phytoplasma affecting peach trees in Jordan.     

Arbuscular mycorrhizal fungus <Emphasis Type="Italic">Rhizophagus irregularis</Emphasis> influences key physiological parameters of olive trees (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) and mineral nutrient profile

In this study, we hypothesized that colonization of olive trees (Olea europaea L.) with the arbuscular mycorrhizal fungus Rhizophagus irregularis could modify the profiles of rhizosphere microbial communities with subsequent effects on nutrient uptake that directly affects olive tree physiology and performance. In this context, a greenhouse experiment was carried out in order to study the effects of mycorrhizal colonization by R. irregularis on photosynthesis, pigment content, carbohydrate profile, and nutrient uptake in olive tree. After six months of growth, photosynthetic rate in mycorrhizal (M) plants was significantly higher than that of nonmycorrhizal plants. A sugar content analysis showed enhanced concentrations of mannitol, fructose, sucrose, raffinose, and trehalose in M roots. We also observed a significant increase in P, K, Ca, Mg, Zn, Fe, and Mn contents in leaves of the M plants. These results are important, since nutrient deficiency often occurs in Mediterranean semiarid ecosystems, where olive trees occupy a major place.     

Detection of a 16SrXII phytoplasma associated with sugarcane yellow leaf syndrome in India

Phytoplasma strain was detected in leaves of sugarcane in India exhibiting symptoms of yellowing of midribs. A phytoplasma characteristic 1.2 kb rDNA PCR product was amplified from DNAs of all diseased samples but not in healthy sugarcane plants tested using phytoplasma universal primer pairs P1/P7 and f5U/r3U. Restriction fragment length polymorphism (RFLP) analysis of amplified 16S rDNA indicated that diseased sugarcane was infected by phytoplasma. The 16S rDNA sequence of the Indian sugarcane yellow leaf phytoplasma (SCYLP) showed the closest identity (99%) to that of SCYLP in Cuba identified as Macroptilium lathyroides (AY725233), which belongs to 16SrXII (Stolbur group). This is the first record of the detection of SCYLP, and identification of the 16SrXII group of phytoplasma associated with yellow leaf syndrome (YLS) in India.     

Characterization of a Phytoplasma Associated with Pear Decline in Iran

Symptoms of pear decline (PD) were observed in several pear growing regions of Iran. Pear trees with typical symptoms of PD from Estahban (Fars Province) were examined for phytoplasma infection using polymerase chain reaction (PCR) assay. Graft inoculation of healthy pear trees with scions from diseased trees resulted in production of PD symptoms and transmission of phytoplasma as verified by PCR. Target DNA was amplified from symptomatic pear trees with fO1/rO1, an apple proliferation (AP) group-specific primer pair. Physical and putative restriction fragment length polymorphism (RFLP) analyses of fO1/rO1 primed PCR products showed profiles corresponding to AP group, 16SrX-C subgroup ( Candidatus Phytoplasma pyri). Percent similarity values and phylogenetic analysis of fO1/rO1 primed sequences confirmed that, as a member of AP subclade, Estahban PD phytoplasma has a closer relationship to PD and peach yellow leaf roll phytoplasmas than to AP ( Ca . Phytoplasma mali) and European stone fruit yellows ( Ca . Phytoplasma prunorum) phytoplasmas. This is the first report of PD phytoplasma in the eastern Mediterranean.     

Molecular Identification of a 16SrII‐A Group‐Related Phytoplasma Associated with Cinnamon Yellow Leaf Disease in China

Chinese cinnamon (Cinnamomum cassia Presl), an evergreen tree native to China, is a multifaceted medicinal plant. The stem bark of cinnamon is used worldwide in traditional and modern medicines and is one of the most popular cooking spices. In recent years, cinnamon with pronounced yellow leaf symptoms has been observed in their natural habitat in Hainan, China. Phytoplasmas were detected from symptomatic cinnamon trees via polymerase chain reaction using phytoplasma universal primers P1/P7 followed by R16F2n/R16R2. No amplification products were obtained from templates of asymptomatic cinnamon trees. These results indicated a direct association between phytoplasma infection and the cinnamon yellow leaf (CYL) disease. Sequence analysis of the CYL phytoplasma 16S rRNA gene determined that CYL phytoplasma is a ‘Candidatus Phytoplasma australasiae’‐related strain. Furthermore, virtual restriction fragment length polymorphism pattern analysis and phylogenetic studies showed that CYL phytoplasma belongs to the peanut witches’‐broom (16SrII) group, subgroup A. This is the first report of a 16SrII group phytoplasma infecting cinnamon under natural conditions.     

Observation of eight ancient olive trees (Olea europaea L.) growing in the Garden of Gethsemane

For thousands of years, olive trees (Olea europaea L.) have been a significant presence and a symbol in the Garden of Gethsemane, a place located at the foot of the Mount of Olives, Jerusalem, remembered for the agony of Jesus Christ before his arrest. This investigation comprises the first morphological and genetic characterization of eight olive trees in the Garden of Gethsemane. Pomological traits, morphometric, and ultrastructural observations as well as SSR (Simple Sequence Repeat) analysis were performed to identify the olive trees. Statistical analyses were conducted to evaluate their morphological variability. The study revealed a low morphological variability and minimal dissimilarity among the olive trees. According to molecular analysis, these trees showed the same allelic profile at all microsatellite loci analyzed. Combining the results of the different analyses carried out in the frame of the present work, we could conclude that the eight olive trees of the Gethsemane Garden have been propagated from a single genotype.     

First record of the olive bud mite Oxycenus maxwelli (Keifer) (Acari: Eriophyidae) from Brazil

The mite Oxycenus maxwelli (Keifer) (Eriophyidae) is reported for the first time in Brazil infesting olive trees, Olea europaea. Specimens were found on seedlings at Maria da Fé, state of Minas Gerais, in 2007. Although minor symptoms were not noticed, significant damage to plants were observed. There is no reliable evidence of when the mite could have been introduced. It is believed that the mite occurs since the first introductions of olive trees, around 1820, through vegetative propagating material, but the mite remained unnoticed due to the lack of studies with olive trees in Brazil.     

Association of ‘Candidatus Phytoplasma cynodontis’ with Bermuda grass white leaf disease and its new hosts in Qassim province,Saudi Arabia

Typical symptoms of phytoplasma such as whitening of the leaves, shortening of the stolons on Bermuda grass, variegated leaves, yellows, stunting, little leaves and yellows on Giant reed, Cooba and sand olive shrub were observed in Qassim province, Saudi Arabia, during the autumn season of 2015. When tested for phytoplasma by universal primers P1/P7 followed by R16mF2/R16mR2, products of approximately 1400?bp (as expected) were amplified from 16 plants with symptoms but not from symptomless plants. Based on sequencing, phylogenetic analysis and virtual restriction fragment length polymorphism patterns of the 16S rDNA F2nR2 fragments of seven Qassim phytoplasma isolates, bermuda grass isolates 170, 175 and 177, giant reed isolate 180, sand olive isolates 181 and 182 and cooba isolate 185, the associated phytoplasma was identified as a member of ‘Candidatus Phytoplasma cynodontis’ which belong to the 16SrXIV-A subgroup. The 16S rDNA gene sequences of seven Qassim phytoplasma isolates exhibited over 99.2% identity with members of ‘Ca. Phytoplasma cynodontis’ group of phytoplasmas. This is the first report of characterization of ‘Ca. phytoplasma cynodonties’ (16SrXIV) associated with Cynodon dactylon in Saudi Arabia and its new hosts, Dodonaea angustifolia, Arundo donax and Acacia salicia.     

Introducing cultivated trees into the wild: Wood pigeons as dispersers of domestic olive seeds

Animals may disperse cultivated trees outside the agricultural land, favoring the naturalization or, even, the invasiveness of domestic plants. However, the ecological and conservation implications of new or unexplored mutualisms between cultivated trees and wild animals are still far from clear. Here, we examine the possible role of an expanding and, locally, overabundant pigeon species (Columba palumbus) as an effective disperser of domestic olive trees (Olea europaea), a widespread cultivated tree, considered a naturalized and invasive species in many areas of the world. By analyzing crop and gizzard content we found that olive fruits were an important food item for pigeons in late winter and spring. A proportion of 40.3% pigeons consumed olive seeds, with an average consumption of 7.8 seeds per pigeon and day. Additionally, most seed sizes (up to 0.7 g) passed undamaged through the gut and were dispersed from cultivated olive orchards to areas covered by protected Mediterranean vegetation, recording minimal dispersal distances of 1.8–7.4 km. Greenhouse experiments showed that seeds dispersed by pigeons significantly favored the germination and establishment in comparison to non-ingested seeds. The ability of pigeons to effectively disperse domestic olive seeds may facilitate the introduction of cultivated olive trees into natural systems, including highly-protected wild olive woodlands. We recommend harvesting ornamental olive trees to reduce both pigeon overpopulation and the spread of artificially selected trees into the natural environment.     

Larval performance in relation to oviposition site preference in olive kernel moth (Prays oleae Bern., Yponomeutidae,Praydina)

1 The tri‐voltine moth Prays oleae Bern. spends its larval stages on the native olive tree (Olea europaea L. var. sylvestris Brot. and five cultivars, Oleaceae) mining the leaves, the flowers and the fruits in each generation; it seldom switches to other native or introduced confamilial plant species. 2 In this study the pattern of oviposition of the olive moth was examined in olive fields and natural vegetation, in relation to in situ recruitment as an outcome of processes such as density dependence or risk spreading. 3 Larval body size (width of epicranial sclerites) was also examined and compared between host substrates, years and morphological, physiological, ecological and nutritional attributes of the host. 4 The factors influencing the oviposition pattern of the olive moth such as the carbon/nitrogen ratio, number of flowers, branch length and previous leaf damage were ranked differently in different cultivars. 5 ‘Hot spots’, i.e. olive trees or parts of trees receiving a high egg load, were found to be the result of in situ recruitment. 6 Physiological mortality among first instar larvae was significantly negatively correlated with the number of oviposited upon leaves; suggesting that the adult selects for oviposition the best available substrate. 7 As adult moths selected leaves with minimal probability of abscission for oviposition, leaf abscission was not a major mortality factor, although first instar larvae reduced leaf longevity. 8 Host quality did not affect all larval stages in the same way. 9 The more nutritionally poor the substrate, the longer the duration of the larval stage feeding on it. The phenological timing of the insect life stages very closely tracks the phenological phases of its host plant, primarily focusing on the most nutritious host stage in terms of larval performance.     

Recovery of Pseudomonas savastanoi pv. savastanoi from symptomless shoots of naturally infected olive trees.

Seasonal dynamics of Pseudomonas savastanoi pv. savastanoi (Psv) on stems and leaves from symptomless shoots of naturally infected olive trees was monitored in Spanish olive orchards. Data inferred from the comparison between washing of leaves and dilution-plating versus leaf printing of individual leaves suggested that Psv population sizes varied by over several orders of magnitude, among leaves sampled concurrently from the same shoot. We did not find significant differences between leaves and stems, in respect to the number of samples where Psv was isolated or detected by PCR, showing that Psv colonizes both leaves and stems. The frequencies of Psv isolation and average populations were highly variable among field plots. No correlation between Psv populations and those of non-Psv bacteria in any plant material or field plot was observed. However, where both Psv and yellow Pantoea agglomerans colonies were isolated a positive correlation was found. In a selected field plot, dynamics of Psv over three years showed significant differences between summer and the rest of seasons. The highest Psv population occurred in warm, rainy months, while low numbers were generally found in hot and dry months.     

Levels of free and conjugated indole-3-acetic acid in ethylene-treated leaves and callus of olive

Changes in levels of free and conjugated indole-acetic acid (IAA) resulting from ethylene treatment were examined in leaves and callus of olive ( Olea europea var. Manzanillo) by electron capture gas chromotography and by isotope dilution analysis. In both olive leaves and olive tissue cultures, the level of free IAA did not change much after the exposure to ethylene, but the levels of bound IAA increased almost three times in comparison with untreated controls. This is the first report of changes in endogenous, bound auxin accompanying ethylene treatment.     

13. Lake Saloio (Nazaré, western Portugal)

The possible impact of altitude and the related microclimatic conditions on the total production of fruiting branches, inflorescences, flowers and pollen grains of olive trees Olea europaea was analysed. A total of 90 Picual cultivar trees, the most extensive olive cultivar in the Iberian Peninsula, were studied for a three-year period (2007–2009). The study shows that production of flowers and pollen grains in a cultivar of the olive tree varies according to the microclimate. Our study also indicates that the olive trees frequently can have up to half a million flowers per tree. Moreover, the total flower production differs between years and study areas. In the Picual cultivar, the average production of pollen grains per anther is usually more than 60?000 grains. The total production of pollen per tree is around 72?000 million on average. The most favourable microclimatic conditions for reproduction in olive trees are found in years and olive growing areas with low temperature and high precipitation records during the months prior to flowering of the olive trees. We hypothesise that olive trees tend to increase their pollen production rate as altitude increases, which can be interpreted as a reproductive strategy to ensure fertilisation.     

Ethylene evolution from various developing organs of olive (Olea europaea) after excision

Ethylene evolution from leaves, stems, inflorescences and fruits of the olive plant ( Olea europaea L.) cv. Manzanillo was studied at various stages of their development. Mature non-growing organs, particularly leaves, have a constant, low, and uniform rate of ethylene evolution. Ethylene evolution from detached mature olive leaves was constant during the first 12 h after excision. Leaves on shoots maintained in vitro kept a constant rate of ethylene evolution for at least the first 5–6 days. Leaf injury significantly increased ethylene evolution. Ethylene evolution from injured and non-injured control leaves could be markedly inhibited aminoethoxyvinylglycine (AVG) applied to the leaves or fed to the shoot. The use of excised olive shoots and leaves as an in vitro model system for studies of induced metabolic processes such as abscission and developing water stress was suggested.     

Induction of growth inhibition and differentiation of human leukemia HL-60 cells by a Tunisian gerboui olive leaf extract

Cancer protection associated with the consumption of olive products is well established, but not for leukemia. The protective effects of olive (Olea europaea L.) leaves were investigated by incubating human promyelocytic leukemia HL-60 cells with olive leaf extracts (OLEs) from seven principal Tunisian olive varieties, namely, Chemchali, Chemlali, Chétoui, Gerboui, Sayali, Zalmati and Zarrazi. The results showed significant growth inhibition of HL-60 cells incubated for 48 h with a 100-fold dilution of each OLE which had been obtained by incubating 10 g of dried leaves in 100 ml of 70% ethanol for one week with subsequent ultrafiltration. DNA fragmentation was observed in the cells incubated for 19 h with a 100-fold dilution of the Chemchali, Chemlali and Zalmati extracts. The results of a nitroblue tetrazolium (NBT) assay revealed NBT reduction, a differentiation marker, by the OLE-treated cells after an overnight incubation. The Gerboui extract showed the highest NBT reduction ability at more than 90%. An HPLC analysis revealed the presence of apigenin 7-glucoside in the extract, which was found in subsequent experiments to be responsible for the Gerboui extract-mediated cell differentiation.     

Molecular identification of Greek olive (Olea europaea) cultivars based on microsatellite loci

Olea europaea is one of the oldest species of domesticated trees. We used microsatellite markers for fingerprinting and for evaluation of genetic similarity and structure of 26 Greek olive cultivars, which cover most of the olive cultivation regions of Greece, including previously undescribed denominations from northern Greece. Eighty-one alleles were revealed with six SSR loci that were selected as most informative of 10 SSR primers that were initially investigated. The number of alleles per locus varied from 7 to 20 (mean, 13.5). Heterozygosity ranged from 0.240 at locus DCA-3 to 0.826 at locus UDO99-9, with a mean value of 0.600. Analysis of 104 trees representing 26 denominations (four trees per denomination) revealed 26 distinct SSR profiles, indicating 26 olive cultivars; no intracultivar variability was observed. Genetic and geographic distances were not significantly correlated, based on the Mantel test. These SSR loci allowed unequivocal identification of all the cultivars and will be useful for future breeding and olive germplasm management efforts.     

Induction of Growth Inhibition and Differentiation of Human Leukemia HL-60 Cells by a Tunisian Gerboui Olive Leaf Extract

Cancer protection associated with the consumption of olive products is well established, but not for leukemia. The protective effects of olive (Olea europaea L.) leaves were investigated by incubating human promyelocytic leukemia HL-60 cells with olive leaf extracts (OLEs) from seven principal Tunisian olive varieties, namely, Chemchali, Chemlali, Chétoui, Gerboui, Sayali, Zalmati and Zarrazi. The results showed significant growth inhibition of HL-60 cells incubated for 48 h with a 100-fold dilution of each OLE which had been obtained by incubating 10 g of dried leaves in 100 ml of 70% ethanol for one week with subsequent ultrafiltration. DNA fragmentation was observed in the cells incubated for 19 h with a 100-fold dilution of the Chemchali, Chemlali and Zalmati extracts. The results of a nitroblue tetrazolium (NBT) assay revealed NBT reduction, a differentiation marker, by the OLE-treated cells after an overnight incubation. The Gerboui extract showed the highest NBT reduction ability at more than 90%. An HPLC analysis revealed the presence of apigenin 7-glucoside in the extract, which was found in subsequent experiments to be responsible for the Gerboui extract-mediated cell differentiation.     

Occurrence and identification of aster yellows related phytoplasma in Gladiolus in Poland

In 1996–1998 on Gladiolus plants cultivated in Poland severe symptoms were observed. The symptoms included chlorosis of the youngest leaves, yellowing and malformation of flower spices, flower discoloration and virescence. The affected corms kept in cold storage developed premature multiple sprouts weak and pale in color. Their root formation was strongly inhibited. Electron microscopy examination of the ultra-thin sections of the leaves and roots of diseased plants showed necrosis and collapsing of sieve tubes and companion cells, reduction of phloem and xylem strands as well as decrease of the number and diameter of xylem vessels. Numerous polymorphic bodies were observed in the phloem and parenchyma cells of affected gladioli. PCR amplification using universal phytoplasma primers rU3 and fU5 directed to ribosomal sequences and RFLP analysis of the amplified rDNA were used to identify the phytoplasma causing yellow disease in Poland. Specific product of about 880 bp was obtained, providing evidence of phytoplasma infection. RFLP analysis of the PCR product done with restriction enzyme AluI showed that the diseased gladioli were infected by phytoplasma very similar or identical with American aster yellows phytoplasma.