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1.
Vitellaria paradoxa or karité is a wild fruit-bearing tree species of sudano-sahelian parklands that plays an important socio-economic role in Sub-Saharan Africa due to the commercial and domestic value of the fruits. Principal constraints of karité fruit production are: long juvenile phase, slow growth, genetic variability and lack of knowledge regarding the cultivation of the species. To address these constraints and to enhance productivity and quality, five methods of grafting (side cleft, top cleft, tongue, chip budding and side veneer), two methods of pre-treatment of scions and rootstocks (washing with 10% sodium hypochlorite to wash off latex and sterilise and a control without washing), and two methods of protection of grafts against desiccation (covering with white plastic sheet and aluminium foil) were tested. The results showed decreasing success of survival of grafts 16 weeks after grafting for the five grafting techniques: side cleft (86.1%), tongue (80.9%), top cleft (78.1%), chip budding (38.1%) and side veneer (20.7%) grafting methods. The results also showed May to be the optimum time for grafting, with high rates of shoot growth and survival of grafts. The average annual growth rate of grafts was 12.6 cm. The pre-treatment of scions with 10% sodium hypochlorite, however, had no significant effect on survival of scions. There was also no significant difference in survival of scions between the two methods of protection of grafts against desiccation (aluminium foil and plastic sheet). Two grafts produced fruits two years after grafting using side veneer grafting.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

2.
Prunus cerasoides has poor regeneration in its natural habitat due to its hard seed coat. The information about maturity time of fruit/seed is scanty and studies on seed germination enhancement lacking. In the present study, the main focus has been given to the physical fruits/seeds attributes which are reliable indicators of maturity and seed pretreatments which help to enhance germination. The fruits/seeds were collected from low and high elevational sites covering the altitudinal range of the species during the period of fruit/seed development (last week of February–mid April) for two consecutive years (2003–2004). The change in fruit colour from dark green to pale red or red was a useful indicator of seed maturity in P. cerasoides. Fruit moisture content between 46.57 ± 0.45% and 56.81 ± 1.14% and seed moisture content between 29.8 ± 1.35% and 34.13 ± 1.50% coincided with maximum germination (41.11 ± 13.96% and 59.99 ± 12.05%) across sites. The removal of seed coat (mechanical treatment) enhanced the germination of seeds to 70 ± 0% at low elevation and 100 ± 0% at high elevation in comparison of control or untreated seeds (germination range between 5.83 ± 0.83% and 31.68 ± 25.02%). Positive correlation existed between seed size and germination (r = 0.280; P < 0.01).  相似文献   

3.
Red flour beetle Tribolium castaneum (Herbst) and rice weevil Sitophilus oryzae (L.) are considered to be the major insect pests in storage. Essential oils from aromatic plants are recognized as proper alternatives to fumigants. Thymus persicus (Ronniger ex Rech. f.) is one of these plants that have medicinal properties and is indigenous to Iran. The essential oil was obtained from aerial parts of the plant and analyzed by GC and GC–MS. Carvacrol (44.69%) and thymol (11.05%) were the major constituents of the oil extracted. In this experiment, fumigant toxicity of the essential oil was studied against T. castaneum, S. oryzae at 27 ± 1°C and 60 ± 5% RH in dark condition. The adult insects were exposed to the concentrations of 51.9, 111.1, 207.4 and 370.4 μl/l air to estimate median lethal time (LT50) values. The fumigant toxicity was increased in response to increased essential oil concentrations. The LT50 values at the lowest and the highest concentrations tested were ranged from 28.09 to 13.47 h for T. castaneum, and 3.86 to 2.30 h for S. oryzae. It was found that S. oryzae adults were much more susceptible to the oil than T. castaneum. After 24 h of exposure, the LC50 values (95% fiducial limit) for T. castaneum and S. oryzae were estimated to be 236.9 (186.27–292.81) and 3.34 (2.62–4.28) μl/l air, respectively. These results suggest that T. persicus essential oil merits further study as potential fumigant for the management of these stored-product insects.  相似文献   

4.
A study was carried out to assess the growth, flowering and fruiting of stecklings (rooted cuttings), grafts and seedlings of Allanblackia floribunda in Cameroun. Thirty-one individuals of each plantlet type were planted in May 2006. Height, collar and crown diameters were recorded in September and October, while flowering and fruiting were recorded each month from January to December. In 2014, the trees with the greatest height were those from seeds (6.98 ± 0.25 m), followed by those from grafts (1.65 ± 0.23 m) and cuttings (1.09 ± 0.21 m). Grafts started flowering and fruiting 3 years after planting, while seedlings started flowering and fruiting after four and 6 years, respectively. Stecklings still had not flowered 8 years after planting. Fruit weight and length from seed-origin trees are about seven times higher than grafts. Correlations between height and crown diameter were significant and positive irrespective of the nature of the planting material. In conclusion, grafts fruited earlier, while seedlings grew faster and had greater yields than grafts and stecklings of A. floribunda.  相似文献   

5.
Thirty-four plant essential oils were screened for their acaricidal and oviposition deterrent activities against two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae), in the laboratory using a leaf-dip bioassay. From initial trials, sandalwood and common thyme oils were observed to be the most effective against TSSM adult females. Subsequent trials confirmed that only sandalwood oil was significantly active (87.2 ± 2.9% mortality) against TSSM adult females. Sandalwood oil also demonstrated oviposition deterring effects based on a 89.3% reduction of the total number of eggs on leaf disks treated with the oil. GC–MS analysis revealed that the main components of the sandalwood oil were α-santalol (45.8%), β-santalol (20.6%), β-sinensal (9.4%), and epi-β-santalol (3.3%). A mixture of α- and β-santalol (51.0:22.9, respectively) produced significantly higher mortality (85.5 ± 2.9%) and oviposition deterrent effects (94.7% reduction in the number of eggs) than the control. Phytotoxicity was not shown on rose shoots to which a 0.1% solution of sandalwood oil was applied.  相似文献   

6.
Acorn production patterns and the annual evolution of water relations parameters of Quercus ilex ssp. ballota (Desf.) Samp. in a dehesa (an open woodland forest) subject to various soil treatments (ploughing, ploughing + sowing, control) were studied in southwest Spain from June 2006 to December 2008. The effects of soil water holding capacity and effective soil depth on soil and plant water status and acorn production were also investigated. Water parameters showed significant differences between the ploughing treatment and the control, and there were also significant temporal differences. Xylem water potential ranged from −3.4 ± 0.1 to −0.7 ± 0.2 MPa, and cuticular transpiration was 62.4–192.9 mmol H2O kg−1 s−1. Acorn production did not differ significantly according to soil treatment, and showed large intra-specific variability. Individual values ranged from 0 to 1,220 g m−2 (fresh weight). Positive relationships were found between xylem water potential, cuticular transpiration and relative water content measured at midsummer, and acorn production during the three studied years. These results suggest that climatic conditions and soil water availability have a strong influence on plant water status, and therefore on acorn development during summer. The results also reflect the ability of this species to adapt to the Mediterranean climate by preserving water during dry periods, which to a large extent can be attributed to stomatal closure at high relative water content levels, and low cuticular transpiration during these periods.  相似文献   

7.
The aphidophagous ladybird beetle, Hippodamia variegata (Goeze), is an important predator in many agricultural ecosystems. However, information on the influence of the prey’s host plant species on its life history characteristics is still absent in the literature. Therefore, five host plant species of Aphis gossypii Glover, viz. Cucumis sativus L., Cucurbita pepo var. medullosa L., Cucurbita moschata var. melonaeformis Poiret, Cucumis melo var. cantalupensis L. and Lagenaria siceraria var. gourda Standl., were selected to study the influence of the prey’s host plant species on the development, survival, reproduction and life table parameters of H. variegata in the laboratory at 25°C. The results showed that all of A. gossypii from five host plant species used were acceptable for the growth, development and reproduction of H. variegata. However, the suitability of aphids from various host plants was different for this ladybird beetle. The complete pre-imaginal development was longest (14.51 ± 0.17 days) when reared with aphids on C. melo var. cantalupensis and shortest (12.60 ± 0.11 days) on L. siceraria var. gourda. Total immature survival from egg to adult was highest (58.97%) on L. siceraria var. gourda and lowest (44.06%) on C. melo var. cantalupensis. Based on the intrinsic rate of increase as an index of suitability of prey host plant species on the population increase of H. variegata, the suitability in decreasing order was: L. siceraria var. gourda > C. moschata var. melonaeformis > C. pepo var. medullosa > C. melo var. cantalupensis > C. sativus. This study offered opportunities for better understanding the tritrophic interactions of the plant–aphid–predator relationship.  相似文献   

8.
Aboveground and belowground biomass of 15-year-old under-planted European beech seedlings (Fagus sylvatica L.) in Norway spruce stand were studied along a light gradient in three plots, in the northern part of Slovenia. Differences in soil water content, aboveground and fine root biomass distribution were confirmed between studied plots. Light had significant effect on the total biomass, root-shoot ratio (0.388 ± 0.076 under canopy, 0.549 ± 0.042 in the edge, 0.656 ± 0.047 in the open), specific root length (SRL) of fine beech roots (561.9 ± 42.2 under canopy, 664.3 ± 51.2 in the edge, 618.2 ± 72.8 in the open) and specific leaf area in beech, indicating morphological adjustment to shade. However, SRL of beech fine roots indicated no change between plots. The correlation between total aboveground and root biomass and light below the mature stand canopy was higher in the case of diffuse light intensity. Most fine roots of spruce were concentrated in the top (0–20 cm) soil layer. Beech fine roots under canopy and edge conditions were also concentrated in top (0–20 cm) soil layer and exhibited shift downwards to deeper soil horizons in open plot. Root proportion between beech and spruce changed with light toward beech with increasing light intensity for both fine and coarse roots.  相似文献   

9.
The olive fruit fly, Bactrocera oleae (Gmelin.) (Diptera:Tephritidae) is a pest on olives (Olea europea) in the Mediterranean basin. An olive fruit fly colony was maintained on olives at 24 ± 1°C, 60% RH, and 16:8 h (light:dark) photoperiod with fluorescent lighting. We investigated oviposition behavior, developmental duration and weights of the biological stages, and adult longevity. A single female laid an average of 19 eggs/day and 200–350 eggs in her lifetime. The maximum number of oviposition stings in a single olive was 156.0 ± 5.77, and 28.00 ± 3.62 larvae out of it completed their development, all pupated, and all emergence successfully. Although the development period was similar for larvae and pupae, adult longevity varied. Male and female emergence percentages ranged as 38.7–52.8, and 32–39.9%, respectively. The results are presented in relation to published studies on olive fruit fly rearing.  相似文献   

10.
Susceptibility of 18 alternate host species to Cronartium flaccidum or C. ribicola was tested. Alive test plants were inoculated in the greenhouse and the formation of Cronartium uredinia and telia was followed on the plants for 8 weeks. Cronartium flaccidum formed uredinia and telia on Bartsia alpina and Euphrasia stricta (Orobanchaceae), Nasa triphylla and N. urens (Loasaceae), Nemesia floribunda (Scrophulariaceae), Tropaeolum majus (Tropaeolaceae), Veronica daurica (Plantaginaceae) and Vincetoxicum hirundinaria (Apocynaceae). Single uredinia or telia developed also on N. urens and E. stricta inoculated with C. ribicola. For the first time, Cronartium are reported to sporulate on members of Loasaceae and Scrophulariaceae, N. urens and N. floribunda.  相似文献   

11.
The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest of canola, Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of integrated management of P. xylostella. We investigated the preferences and performance of P. xylostella on nine commercial cultivars of canola, namely Zarfam, RGS003, Adder, Okapi, Opera, Hyola401, Ebonite Option500 and Elite under greenhouse conditions at 23 ± 1°C, 50 ± 5% RH and 14L:10D. In free-choice situation, oviposition was lowest on Opera (23.5) and highest on Zarfam (44.7). In the life table study, fecundity of new generation female moths was lowest on Opera (95.4) and highest on Adder (145.7). Survival from egg to adult was significantly lower on Opera, Option500 and Hyola401 than on other tested cultivars. The intrinsic rate of natural increase (r m) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Zarfam (17.2 days) and longest on Hyola401 (19.9 days) whereas doubling time (DT) was longest on Opera (3.9 days) and shortest on Zarfam (3.0 days). Our results clearly suggest that Opera was the most resistant host among the tested cultivars and has the potential to be used in the integrated management of P. xylostella.  相似文献   

12.
Generic or default values to account for biomass and carbon accumulation in tropical forest ecosystems are generally recognized as a major source of errors, making site and species specific data the best way to achieve precise and reliable estimates. The objective of our study was to determine carbon in various components (leaves, branches, stems, structural roots and soil) of single-species plantations of Vochysia guatemalensis and Hieronyma alchorneoides from 0 to 16 years of age. Carbon fraction in the biomass, mean (±standard deviation), for the different pools varied between 38.5 and 49.7% (±3 and 3.8). Accumulated carbon in the biomass increased with the plantation age, with mean annual increments of 7.1 and 5.3 Mg ha−1 year−1 for forest plantations of V. guatemalensis and H. alchorneoides, respectively. At all ages, 66.3% (±10.6) of total biomass was found within the aboveground tree components, while 18.6% (±20.9) was found in structural roots. The soil (0–30 cm) contained 62.2 (±13) and 71.5% (±17.1) of the total carbon (biomass plus soil) under V. guatemalensis and H. alchorneoides, respectively. Mean annual increment for carbon in the soil was 1.7 and 1.3 Mg ha−1 year−1 in V. guatemalensis and H. alchorneoides. Allometric equations were constructed to estimate total biomass and carbon in the biomass which had an R 2aj (adjusted R square) greater than 94.5%. Finally, we compare our results to those that could have resulted from the use of default values, showing how site and species specific data contribute to the overall goal of improving carbon estimates and providing a more reliable account of the mitigation potential of forestry activities on climate change.  相似文献   

13.
Element content and pH value in wood tissues of veneer grade logs of P. serotina Ehrh. were investigated with regard to wood colour variations, measured in the CIEL*a*b* system. The average pH value of heartwood tissue was about pH 4.0 and medium colour parameters of veneer sheets were determined at L* = 73, a* = 9.8, and b* = 23.5. Optical emission spectroscopy (ICP-OES) analyses showed differences in the element contents between two regional forest sites coming from Pennsylvania and West Virginia, USA, respectively. The latter is mainly characterised by higher variations of micro-element content in the transition zone (influencing heartwood formation) and also pH value of wood tissue, which contributes to higher variations in colour response of industrially produced veneer sheets. Investigations under industrial conditions underline the correlation between length and intensity of heat treatment in veneer production and colour development: with increasing duration and temperature of hot water treatment, veneer surfaces become darker and wood colour is intensified (ΔL = 3.6, Δa = 2.1, comparing 12 and 72 h of hot water treatment at 60°C). However, no equalisation of wood colour was achieved by modifying the treatment conditions. Artificial radiation by UV–visible light, quickly and extensively darkens and intensifies wood colour (ΔL = 16, Δa = 3.5, and Δb = 4.0 after 15 h of artificial radiation), but variations in wood colour deriving from different treatment conditions during veneer production, were not reduced.  相似文献   

14.
The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and the onion thrips, Thrips tabaci Lind. (Thysanoptera: Thripidae), are significant field pests of potato in the Ardabil region of Iran. Orius niger (Wolf.) and O. minutus (L.) (Hemiptera: Anthocoridae) are locally the predominant natural enemies of these pests. This study compared the functional responses of O. niger and O. minutus to female mites and second instar thrips larvae across a range of prey densities (5, 10, 20, and 40 prey/arena) under controlled conditions of 24 ± 1°C, 50 ± 5% RH and 16:8 h (L:D). The resulting data were appropriately fit to Type II functional response models in four predator–prey interactions, including: (1) O. niger to second instar thrips larvae (a = 0.009 h−1; and T h = 1.62 h); (2) O. niger to females mites (a = 0.006 h−1 and T h = 1.28 h); (3) O. minutus to second instar thrips larvae (a = 0.008 h−1 and T h = 1.93 h) and (4) O. minutus to females mites (a = 0.01 h−1 and T h = 1.1 h). The number of second instar thrips larvae attacked by O. niger was greater than that by O. minutus (P ≤ 0.01); conversely, the number of females mites attacked by O. minutus was greater than that by O. niger (P ≤ 0.01). These results confirm the potential for both O. niger and O. minutus to make valuable contributions to a biological control program against onion thrips and the two-spotted spider mites infesting potato fields in this region.  相似文献   

15.
The two-spotted spider mite, Tetranychus urticae Koch, is a very polyphagous pest with a worldwide distribution. In order to appraise population growth parameters of this pest, samples of two-spotted spider mites were taken from soybean (Glycine max) fields of Moghan region, Iran in June 2007 and are reared on bean plants var. Derakhshan (Phaseolus vulgaris) in a growth chamber. The life table parameters of this pest were calculated on three commercial soybean cultivars (Zane, Hach, and L17) and one hybrid (Hob × Will) at 25 ± 1°C, 60 ± 10%RH, and 16 h photophase. The developmental times of immature stages varied from 9.69 on Hach to 9.82 days on L17, whereas the immature survival was 57–79% on Hach and Hob × Will, respectively. On average, there were 65.5, 40.8, 38.8 and 34 eggs produced per female on L17, Hach, Hob × Will and Zane, respectively. The intrinsic rate of natural increase (r m ) for T. urticae on Hob × Will was the highest, whereas the values for r m ranged from 0.211 (females/female/day) on Zane to 0.292 on Hob × Will. Also, jackknife values of other life table parameters such as net reproductive rate (R 0), generation times (T), doubling time (DT), and finite rate of increase (λ) on these cultivars were estimated. Overall, the two-spotted spider mite indicated a better performance on Hob × Will than on the other soybean cultivars.  相似文献   

16.
The methanol (MeOH) extract of Populus ussuriensis Kom. bark was analyzed for antioxidant assessing by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging potential. Among fractions using several solvents, the ethyl acetate (EtOAc) soluble fraction, which showed strong antioxidant activity (IC50 2.02 ± 0.01 μg/ml), was further purified by Thin layer chromatography (TLC) guided Sephadex LH-20 column chromatography. Three known phenolic glucosides, picein (I), salicortin (II), grandidentatin (III), and that of a new, 2-hydroxycyclohexyl-4′-O-p-coumaroyl-β-d-glucopyranoside (isograndidentatin A), were isolated and their structures were elucidated on the basis of physiochemical and spectroscopic methods. This was the first report of the chemical composition of P. ussuriensis bark. Phenolic glucosides III and IV exhibited strong antioxidant activities, with IC50 values 6.73 ± 0.01 and 6.69 ± 0.01 μM, respectively, comparable to the control (α-tocopherol, IC50 6.80 ± 0.01 μM). P. ussuriensis bark EtOAc-soluble fraction and compounds III and IV could be used as biopreservatives in food applications as well as for cosmetic and medicinal preparations, to alleviate oxidative stress.  相似文献   

17.
Fumigant activity of essential oil vapors distilled from Carum copticum C. B. Clarke and Vitex pseudo-negundo Hand I. MZT. was tested against eggs, larvae and adults of Callosobruchus maculatus (F.). Fumigant toxicity was assessed at 27 ± 1°C and 60 ± 5% RH, in dark condition. The influence of different concentrations of the essential oil vapors on egg hatchability, larval and adult mortality was significant. Data probit analysis showed that lethal concentration of the essential oil to kill 50% of the population (LC50) for egg, larvae and adult were found to be 1.01, 2.50 and 0.90 μl/l air of C. copticum oil, followed by 2.20, 8.42 and 9.39 μl/l air essential oil of V. pseudo-negundo, respectively. Between these essential oils, C. copticum was almost more toxic than V. pseudo-negundo on all growth stages of C. maculatus. The present study suggests that essential oils from these medicinal plants may be potential grain protectants as botanical alternative fumigants and could be used in the management of various life stages of C. maculatus.  相似文献   

18.
Lymantria dispar (Lep., Lymantriidae), an important forest defoliator, is host for a variety of entomopathogenic microsporidia. These are obligate intracellular parasites that completely depend on resources provided by the hosts. The microsporidia infecting L. dispar differ in the host tissues that become infected as well as in virulence, with presumably different effects on host physiology. Endoreticulatus schubergi infects the midgut tissue of the host; its virulence is low. We studied the effects of infection with E. schubergi on carbohydrate and lipid levels in the L. dispar host larva. Trehalose titer in the hemolymph increased with larval age. There were no significant differences between infected and uninfected hosts. Glycogen content of the host tissue also increased with age. Levels of this storage carbohydrate were significantly lower in infected larvae at a late stage of infection when insects were either full grown larvae prior to pupation (57.4 ± 5.7 and 36.4 ± 5.2 μg/mg in uninfected controls and infected hosts, respectively) or prepupae (53.2 ± 3.4 vs. 34.7 ± 4.7 μg/mg). Lipid levels in host tissue likewise increased over time and were slightly but not significantly lower in infected L. dispar at a late stage. The results suggest that L. dispar larvae are able to compensate for most of the loss of nutrients to the developing microsporidia. Differences between these findings and the effects of infection with the virulent microsporidium, Vairimorpha disparis, that infects the host’s fat body and causes severe depletion of nutrients in L. dispar larvae are discussed.  相似文献   

19.
An efficient regeneration protocol for rapid mass propagation and uptake of heavy metals in Albizia lebbeck (L.), a fast growing, medicinally as well as economically important timber yielding tree was developed. Nodal segments derived from a 20-year-old tree were cultured on MS (Murashige and Skoog) medium supplemented with 10 μM 6-Benzyladenine (BA) and 1 μM α-Naphthalene acetic acid (NAA) showed optimum shoot regeneration frequency (76.6%), number of shoots (23.2 ± 0.28) per explant and shoot length (2.86 ± 0.08 cm) after 10 weeks of culture. After standardizing a reliable protocol for micropropagation, effects of ZnSO4 (0.06–0.48 mM), CuSO4 (0.02–0.2 mM) and CdCl2 (0.0001–0.001 mM) on shoot morphogenesis were also assessed. The regenerated shoots maintained on maintenance medium (MS + 10.0 μM BA + 1.0 μM NAA) containing ZnSO4 (0.06 mM) showed maximum response in terms of shoot number (24.5 ± 0.83) and length (5.9 ± 0.05 cm) after 10 weeks of culture. Proline content showed an increasing trend while chlorophyll (a and b) content exhibited decreasing trend with an increased metal concentrations compared to MM cultures, and maximum increase in proline and decrease in chlorophyll content was recorded in cultures grown on Cd-enriched medium. Best rooting was accomplished on half strength MS medium with 2.0 μM IBA and ZnSO4 (0.06 mM). The plantlets thus obtained were successfully hardened and transferred to greenhouse with 75% survival rate and exhibited normal morphological characteristics compared to donor plant.  相似文献   

20.
In vitro propagation technique of Balanites aegyptiaca, a multipurpose woody tree was studied. Nodal segments including axillary bud from mature tree were used as an explant and their morphogenetic potential was tested on MS media with various concentrations (2.5–15.0 μM) of 6-benzyladenine (BA), Kinetin, and Thidiazuron alone or in combination with different concentrations (0.5–2.5 μM) of α-naphthalene acetic acid (NAA). Nodal segments showed axillary bud proliferation in almost all media tried. MS medium containing 12.5 μM BA alone was effective for inducing multiple shoots (5.0 ± 0.22) with an average shoot length (3.7 ± 0.26 cm) in 67% of cultures. A better shoot differentiation and elongation was achieved in a combined treatment of BA (12.5 μM) and NAA (1.0 μM). Half strength MS medium supplemented with Indole-3-butyric acid (IBA) gave the best result for rooting. The maximum frequency of root formation (68%), number of roots (5.3 ± 0.32) and root length (4.1 ± 0.38 cm) was obtained on half strength MS medium containing 1.0 μM IBA. The regenerated plantlets were potted and acclimatized successfully in a growth chamber and then moved to the greenhouse.  相似文献   

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