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1.
S. De Smedt K. Alaerts A. M. Kouyaté P. Van Damme G. Potters R. Samson 《Agroforestry Systems》2011,82(1):87-97
We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed
along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was
partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp + seed and total weight, and between pulp
and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between
trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that
there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties,
e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably
increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: >100 g). The same might be true
for seed production (mean: 71 ± 2 g, best 5%: >150 g). Also the ratio between pulp and seed weight can be an important fruit
characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two
fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp
weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability
in traits of baobab fruit in Mali, offering opportunities for cultivar selection. 相似文献
2.
Jan Svejgaard Jensen Jules Bayala Haby Sanou Adama Korbo Anders Ræbild Sié Kambou Abasse Tougiani Henri-Noël Bouda Anders Søndergaard Larsen Charles Parkouda 《New Forests》2011,41(3):317-335
The Baobab tree (Adansonia digitata L.) is a key multipurpose species for the African region. In the recent years there has been an extended commercial interest
for different A. digitata products. As a spectacular African key species there has been a growing interest from NGO′s and various research groups.
A research group, focussing on the following countries Burkina Faso, Mali and Niger, has participated in a concerted research
action with cross counter disciplinary cooperation between plant physiology, population genetics, tree breeding, food science,
and socioeconomics. This paper presents a review and the way knowledge gaps are being addressed using the above mentioned
approach. The overall work was initiated in 2005–2006 when a large collection of A. digitata seeds was carried out in 15 African countries. Fourteen populations were selected in Burkina Faso, Mali, and Niger including
more than 400 superior trees, and many of the trees have been selected along with farmers in a participatory process. Studies
have been initiated in all countries on geographic variation of growth, adaptive and phenological traits. This includes studies
in the nursery, establishment of international provenance series, seed orchards and studies of gene flow and phylogeographic
variation with various markers. Specific nursery trials have been established in order to study provenance and progeny performance
related to drought stress. Several stress related characteristics are being measured. Preliminary observations showed large
morphological variation between African provenances of A. digitata. Food properties of plant parts have been studied within and between populations. This includes studies of total biomass
production, vitamin A, B1, B2, and various minerals. The influence of stress will be related to these parameters. Fruits,
which are rich in sugar and vitamin C, are used as an ingredient in juice and other foods. Seeds can be used directly as food
ingredient or in fermented condition (Maari). The fermentation process was previously poorly described. Therefore, the microorganisms
associated with Baobab seeds fermentation have been identified and a starter cultures for control production has been proposed.
The efficiency of dissemination of superior A. digitata trees depends on vegetative propagation. Various grafting methods are currently being tested in cooperation with farmers.
Micropropagation is tested as well as a method for clone propagation. The accumulated knowledge will be applied for a domestication
strategy of A. digitata in Burkina Faso, Mali and Niger. The outcome from this study will be guidelines for protection and management of the germplasm
of A. digitata resources. 相似文献
3.
A study was conducted to determine the effects of electrostatic field (ESF) treatment on seed germination and seedling growth
of Sorbus pohuashanesis. The experiments were arranged by uniform design computed by the Data Processing System (DPS), including three levels of
seeds soaking time, four levels of ESF intensity and four levels of ESF treatment time, with 12 treatments. Ten seeds were
used in each treatment with three replicates. Seed vigor, seed germinating ability, emergence rate of seedling, survival rate
of seedling, and seedling height and diameter, as well as the change in activities of superoxide dismutase (SOD), soluble
protein contents, total chlorophyll contents, soluble total sugar contents in leaves of S. pohuashanensis seedlings were measured after ESF treatments. The experiment results show that ESF treatment could improve the water absorption
ability of dry seeds of S. pohuashanensis, resulting in fast germination at room temperature under light conditions. Combined treatment of ESF with cold stratification
could increase seed germination percentage significantly (to 42.20%), promote seedling height growth, affect leaf SOD activity,
and could raise contents of total chlorophyll, soluble protein, and total soluble sugar in leaves. Seed soaking time had a
significant effect on seed relative electroconductivity, seed germination under light, SOD activity, soluble protein content
and total soluble sugar content of seedling leaves. ESF intensity exerted a moderate effect on these indexes. ESF treatment
time only had significant effect on total chlorophyll contents, no evident effect on other indexes. 相似文献
4.
Brenda Colleen Clifton-Cardoso Marcelo Schramm Mielke José Roberto De Melo Rondinele Nascimento Querino 《New Forests》2008,35(1):15-31
Dimorphandra jorgei MF Silva (Caesalpinaceae) and Swartzia macrostachya Benth. var. riedelii Cowan (Fabaceae) are tree species from the southern Bahian Atlantic Forest, identified for the restoration of degraded areas.
The objective of this research is to study their seed germination and seedling growth to develop simple methods for seedling
production in small scale nurseries. Because the species have distinct dormancy and germination characteristics, the seeds
were submitted to different treatments. D. jorgei seeds were immersed in hot water, scarified and stored for 12 weeks in the laboratory environment (25°C). S. macrostachya seeds were submitted to different combinations of drying and storage in the laboratory environment or refrigerator (4°C).
Seedlings were submitted to two light treatments for 3 months: partial shade (52% of full sun) and full shade (12% of full
sun). In D. jorgei, the highest germination occurred for scarified seeds (87%) and for seeds stored for 12 weeks and then scarified (69%). In
S. macrostachya the undried control seeds had the highest germination, followed by that of the refrigeration storage treatment, without predrying
(99% and 97%, respectively). The average values for the growth parameters were greater in full shade for D. jorgei, while S. macrostachya seedlings showed greater growth rates in partial shade. Two months growth is recommended before D. jorgei seedlings are of the sufficient size and leaf number for field planting. On the other hand, a period of 4 months is recommended
for S. macrostachya, due to its relatively slow growth. 相似文献
5.
For improving seed germination of Prosopis koelziana and Prosopis juliflora, different treatments of seeds were conducted, including scarification with sulfuric acid 98% for 10 and 15 min, sandy paper,
hot water for 5 and 10 min, potasium nitrate 0.1%, gibberellic acid at 250 mg·L−1 and 500 mg·L−1 and combinational treatment of scarification with gibberellic acid of 250 mg·L−1 and 500 mg·L−1. The results show that scarifications with sandy paper and sulfuric acids 98% were the most effective treatments on breaking
seed dormancy and seed germination induction. Scarification with sulfuric acid 98% for 15 min was the best treatment. According
to the positive effect of scarification and lack of reaction of seeds against KNO3 and gibberellic acid, the kind of seed dormancy was determined as exogenous. 相似文献
6.
Nursery practice using microbial inoculants was performed to find out the efficacy of the inoculants on seed germination and
seedling growth of sissoo (Dalbergia sissoo Roxb.). Microbial inoculants or effective microorganisms (EM) are a mixture of many different beneficial microorganisms in
a solution. The seedlings were grown in a mixture of sandy soil and cowdung (3:1) kept in polybags with pouring EM solution
at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) before and after a week of sowing the seeds. Seed germination
rate and growth parameters of seedlings were measured, such as, shoot and root length, vigor index, fresh and dry weight of
shoot and root and total biomass increment. The nodulation status influenced by EM was also observed along with the measurement
of pigment contents in leaves. The highest germination rate (69%) was observed in 2% EM treatment, followed by 67% and 65%
in 1% and 5% EM. The highest shoot length (33.2 cm) was in 2% EM, whereas highest root length (26.3 cm) was in 1% EM. Both
fresh and dry weights from shoot and root, were maximum (4.16 g and 1.57 g; 2.12 g and 0.83 g respectively) in 2% EM and were
significantly (p ≤ 0.05) different from control. Vigor index was highest (4071) in 2% EM, which was significantly (p ≤ 0.05) different from control. Total dry weight increment was highest in 2% EM treatment, followed by 1% and 5% concentrations
of EM. Nodulation number was higher at very low (0.1%) concentration of EM solution but it normally decreased with the increase
of EM concentrations. The contents of chlorophyll a, chlorophyll b and carotenoid were highest (60.11, 17.05 and 42.48 mg·L−1 respectively) in 2% EM treatment and lowest (39.35, 13.55 and 27.29 mg·L−1 respectively) in control treatment. Therefore, low concentration of EM (up to 2%) can be used for getting maximum seed germination
rate and seedling development of Dalbergia sissoo Roxb. 相似文献
7.
Semecarpus kurzii Engl. is an important ethnomedicinal plant used for curing tumours, inflammation, fever and pain, and is also a source of iso ricinoleic acid. During the present investigation, effect of chemical pre-treatments on germination and seedling growth revealed significant differences. Different pre-treatments could improve germination and treatment with KNO3 (9.9 mM) was significantly superior (94%) to the untreated control (76%). Mean daily germination varied among the treatments (0.90–4.14 seeds per day), when compared with 2.27 seeds per day in control. Mean germination time was significantly reduced from 22.14 days (control) to 16.40 days (19.8 mM KNO3) and 17.16 days (1.45 mM GA3). Treatment with KNO3 (19.8 mM) and GA3 (1.45 and 2.90 mM) significantly reduced the time for 50% germination. Treatment with higher concentrations of GA3 and KNO3 exhibited significantly faster germination initiation (11.0 and 12.0 days, respectively) over the control (17.0 days). Seedling vigour index was not improved by pre-treatments. Chemical treatments did not improve shoot growth, collar thickness, or number of seedling leaves; however, root growth was significantly improved over control. Treatment with GA3 (2.90 mM) promoted leaf elongation but reduced leaf width significantly. Treatment with KNO3 and GA3 could be recommended to obtain healthy seedlings for establishing new plantations of this important medicinal plant species. 相似文献
8.
Balbir Singh Rawat Vinod Prasad Khanduri Chandra Mohan Sharma 《林业研究》2008,19(2):125-130
研究赤霉素(GA3),冷湿和温度 对五个种源的印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana)种子萌发的影响.种子被浸泡在GA3 (10 mg(L-1)中24小时,然后在3(5(C温度的条件下冷藏15天.设计4个温度(10(C, 15(C, 20(C 和 25(C)条件来促进种子的萌发.结果表明,浸泡和冷湿处理明显增加种子的萌发率.在10 (C时种子的萌发率最高.总体结果表明,种子被浸泡在GA3 (10 mg(L-1)中24小时,冷湿藏15天,可以有效地促进印度冷杉和长叶云杉的种子萌发.统计数据表明,浸泡处理、温度和种源以及与温度的相互作用都对种子的萌发有明显的影响. 相似文献
9.
The germination of common alder (Alnus glutinosa (L.) Gaertn.) and downey birch (Betula pubescens Ehrh.) seeds is often poor in bare-root nurseries. The effect of a variety of seed coverings and a few seed pretreatments
on seedling emergence was examined in this study in an attempt to address this problem. Seeds of each species were sown in
trays containing nursery soil, covered with grit, gravel, sand, combinations of these coverings, a hydromulch or a sealed
plastic cloche and then incubated for 6 weeks at 17–20°C. The grit combined with sand or gravel, the hydromulch and the cloche
increased seedling emergence when compared with the standard grit. In another experiment, seeds of each species were fully
imbibed (FI) (>50% moisture content, MC), as per standard practice, or adjusted to target MC (TMC) (30–35% MC) levels, and
then chilled to release dormancy. Some seeds of each MC treatment were primed at 20°C for 2 days following chilling, after
which all seeds were evaluated in laboratory tests and a nursery trial. Germination potential of the FI seeds declined in
the lab tests by the second test date, which was reflected in low seedling emergence in the nursery in birch. The primed FI
seeds of alder germinated most rapidly in the nursery, but other effects were not significant. Seedling emergence was better
in the nursery in response to the TMC than the FI pretreatment in birch.
相似文献
Conor O’ReillyEmail: |
10.
Fertility variation and effective number of parents were estimated in the 100 individuals from each of three plantation populations (P1, P2 and P3) of the endangered Pinus nigra. subsp. pallasiana var. pyramidata established in the Isparta–Golcuk district in southern Turkey in 1990. Potential relations between cone yield and growth characters (height, diameter at breast height, diameter at base and crown diameter) were also investigated. Large differences were found among populations and within populations for cone production and growth characters. Mean cone production was eight (ranging from 6.5 in P2 to 9.1 in P1) for the three populations. The 10 most productive individuals for cones produced 32% of the total cones in P1, 39% in P2 and 34% in P3; 21, 16 and 6 individuals, respectively did not produce any cones in the populations. According to the correlation analyses, the relation between cone yield and growth characters changed for the populations, while height, diameter at breast height and crown diameter were positively significantly correlated (r = 0.182, 0.135 and 0.209; p ≤ 0.05) with cone production for the three populations. Fertility variation was 1.81 in total of three populations, ranging from 1.72 in P3 to 3.45 in P1). Effective number of parents was 142 (55.2 of number of parents censused; 29%, P1; 49.8%, P2; 58.3%, P3). 相似文献
11.
The problem of salinized soils has become one of the most serious constraints to agricultural and forest productivity. With the purpose of enhancing salt stress tolerance of Populus tomentosa, we transformed this tree species with spermidine synthase (SPDS) genes derived from an apple by an Agrobacterium-mediated method. Four transgenic clones were confu'med by PCR and Southern blot analysis. As well, the expression of introduced SPDS genes was analyzed by real-time quantitative PCR. 相似文献
12.
Pinus densiflora f.umbraculifera, commonly known as utsukushimatsu, is a distinctively shaped form of Japanese red pine whose growth is restricted to a forest
stand in Shiga Prefecture, Japan. The inheritance mode of morphological characteristics of utsukushimatsu was studied to preserve
the genetic resource of this pine. As previously reported, F1 trees grown from open-pollinated seeds harvested from trees inhabiting the native stand showed two phenotypes: one resembling
utsukushimatsu, which produces multiple trunks, and the other resembling normalP. densiflora, which produces one or a few trunks. In the present study, controlled pollination was carried out using F1 and normalP. densiflora trees. Segregation ratios of the two phenotypes observed in the F2 population showed that the morphological characteristics of utsukushimatsu are inherited recessively. This suggests that
the mutation of one gene or a few closely linked genes controls the morphological characteristics of utsukushimatsu. Since
multiple trunk formation of utsukushimatsu might be related to a loss of lateral bud inhibition, it follows that a simple
gene mutation breaks apical dominance inP. densiflora. 相似文献
13.
Robert Brus Dalibor Ballian Peter Zhelev Marija Pandža Martin Bobinac Jane Acevski Yannis Raftoyannis Kristjan Jarni 《European Journal of Forest Research》2011,130(4):657-670
We examined leaf and mature seed cone variation of Juniperus oxycedrus L. subsp. oxycedrus in 12 natural populations across the species range in the Balkan Peninsula. We measured 10 morphological traits from a minimum
of 100 leaves in each of 190 individuals, and two morphological traits from 30–50 seed cones in each of 94 females. High phenotypic
variation was found, but no geographical structure or cline across populations was detected for any of the studied traits.
Mean values of comparable leaf and cone morphological traits did not differ considerably from values reported elsewhere. Gender
dimorphism in leaf morphology was detected, but it was not distributed uniformly throughout the studied area. An ANOVA model
with both nested and crossed effects revealed that the largest proportion of the total variation was, as expected, contained
within populations, partly as among-tree variation (18–47%, depending on the trait) and partly as within-tree variation (33–77%),
which was remarkably high. Gender dimorphism explained only 0–3% of the total variation. Differences among populations (2–23%)
were significant for all studied traits except one; however, PCA showed no clear geographical differentiation of the studied
populations. This lack of phylogeographical structure may be the consequence of repeatedly occurring colonisation-retreat
scenarios and suggests the existence of several small refugial populations scattered over a large part of the Balkan Peninsula
in the Pleistocene. Further research including palaeobotanical and molecular genetic studies will be needed to better understand
the forces that shaped current variation patterns of J. oxycedrus L. subsp. oxycedrus in the Balkan Peninsula. 相似文献
14.
Gudeta W. Sileshi Festus K. Akinnifesi France M. Gondwe Oluyede C. Ajayi Simon Mng’omba Konisaga Mwafongo 《Agroforestry Systems》2011,83(3):361-372
The production of paprika (Capsicum annum L.) under small-scale farm conditions in southern Africa is constrained by low soil fertility and lack of appropriate cultivars.
The objective of this study was to determine the growth responses and fruit yields of six cultivars of paprika to organic
and inorganic nutrient sources. The study was conducted in 2007 and 2008 at Chitedze Agricultural Research Station in Malawi.
A combination of six paprika cultivars and four nutrient sources, namely (1) organic input from Gliricidia, (Gliricidia sepium) biomass, (2) inorganic fertilizer, (3) integrated nutrient input (Gliricidia biomass + inorganic fertilizer), and (4) control
(no nutrient input) were compared. Each combination was replicated five times. A split-plot design was used where nutrient
sources formed the main plot and cultivars the sub-plots. Plant height differed due to nutrient source in 2007 and 2008, while
differences due to cultivar were minor. The control plots produced the shortest plants (height < 50 cm), while plots receiving
the integrated nutrient input produced the tallest plants (height > 60 cm). Numbers of branches and fruits per plant differed
due to nutrient source and cultivar during most of the study period. Plants receiving either organic inputs (Gliricidia biomass)
alone or the integrated nutrient input alone had significantly higher stem, leaf and fruit weight compared with the control.
Average fruit yield was lower in control plots than in plots receiving the organic input alone or the integrated nutrient
input. Among cultivars, Papri-King, Papri-Supreme and Papri-Queen produced higher dry fruit yield. The ASTA and RAL colour
rating was within the internationally accepted range for fruit from the treatments. 相似文献
15.
Leucaena leucocephala and Acacia farnesiana are tree species used for several agricultural purposes in the Mediterranean region. The seeds of these species exhibit dormancy,
causing delayed germination. Two experiments were conducted to investigate the effect of pre-sowing treatments (scarification,
hot water, or soaking) on seed germination of L. leucocephala and A. farnesiana. In one experiment, seeds were exposed to three pre-sowing treatments: control, sandpaper scarification, or soaking in 70°C
water for 4, 8, 12, 16, 20, or 24 min. In another experiment, seeds were soaked in 70°C water for 20 min, and then soaked
in water at room temperature for an additional 24, 48, or 72 h or blade scarified. In general, soaking the seeds of the two
species in hot water was more effective in breaking seed dormancy than scarification. Sandpaper scarification was not effective
for either species. Blade scarification increased A. farnesiana seed germination to 56%, indicating that seed dormancy was mainly a consequence of hardseededness.
L. leucocephala seeds collected from Jordan University of Science and Technology (JUST) site and soaked in 70°C water for 20 min and then
soaked for 24, 48, or 72 h had germination rates above 97%. Our results suggest that blade scarification of A. farnesiana seeds and soaking of L. leucocephala seeds in 70°C water for 20 min are effective treatments to break seed dormancy and enhance seed germination of these vital
species. 相似文献
16.
Jatropha curcas L. is being promoted by governments for greening marginal areas for rural development and biodiesel production in sub-Saharan Africa, however large gaps in knowledge on its agronomy and yield potential exist. The effect of duration of storage at room temperature, pre-sowing seed treatment of Jatropha seed and fruit colour harvest index on germination and seedling growth parameters was investigated. There was a significant negative correlation between the duration of storage of Jatropha seed and seed oil content (P < 0.001, r = ?0.99), viability (P < 0.01, r = ?0.93), percent germination (P < 0.05, r = ?0.90) and germination index (P < 0.05, r = ?0.89). The relationship between duration of seed storage and seed oil content and seed germination parameters was best described by quadratic and exponential functions which showed rapid declines in seed oil content and germination parameters in the first 3 years of storage and a slower decline between 3 and 8 years of storage. There was a significant negative correlation between duration of storage and seedling height (P < 0.01, r = ?0.97), stem diameter (P < 0.01, r = ?0.93) and dry weight (P < 0.05, r = 0.91) that was best described by quadratic functions. Seed oil content was significantly and positively correlated to seed viability (P < 0.01, r = 0.96), germination per cent (P < 0.01, r = 0.94) and germination index (P < 0.01, r = 0.93). The relationship between seed oil content and seed germination parameters was best described by exponential functions which showed an exponential increase in seed germination parameters as oil content increased above 30% and smaller increases below 30% oil content. Progressive peroxidation of lipids as seed aged explains the loss of oil from the seed. Peroxidation of lipids produced highly reactive radicals that damaged membranes and proteins reducing seed germination and seedling growth parameters as seed aged. Pre-sowing seed treatments (seed soaking and scarification) produced marginal gains in germination and seedling growth parameters in Jatropha seed stored for 3 months to 8 years. Seeds harvested at the yellow fruit maturity index, 60 days after anthesis (DAA), showed the highest seed germination percent while seed harvested at the black fruit maturity index, 75 DAA, had the highest oil content. Harvesting of Jatropha seed for oil expression is therefore recommended at the black maturity index while harvesting for seed is recommended at the yellow maturity stage. The results of this study indicate that Jatropha seed should be stored for as short a period of time as possible to maximize seed germination, seedling growth and oil yield. 相似文献
17.
The morphology of charcoals was investigated by scanning electron microscopy. Charcoal of Quercus variabilis was prepared in an electric furnace under nitrogen gas atmosphere at 400, 600, 800 and 1,000°C. Charring temperature greatly affects the structure of charcoal. In charcoal prepared at 400°C, most of the morphological characteristics remained relatively unchanged with the exception of the cell-wall layering. The cell walls appeared homogenous and glass-like. Above 400°C, there was an increase in cell-wall thinning and volumetric shrinkage with an increase in the charring temperature. These two factors were responsible for most of the observed changes in structure. Fracture surfaces became increasingly rough and disrupted. Vessel elements were increasingly distorted and tyloses disintegrated with increases in temperature. Parenchyma cells exhibited greater shrinkage except at the pits. This resulted in the appearance of distinctive small protuberances over the surface of the parenchyma cells. Rhomboidal calcium crystals were found to be abundant at all the temperatures studied, but at 800 and 1,000°C the crystals had a sponge-like appearance. 相似文献
18.
A germination experiment of pre-treated seeds of Melia azedarach was conducted in the nursery of Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Matured seeds of
Melia azedarach were collected from healthy trees of National Botanical Garden, Bangladesh and were treated with five pre-sowing treatments
(control, immersion in cold water, immersion in hot water, scarification with sand paper, and immersion in concentrated H2SO4) on seed germination. Results revealed that the germination rates of pre-sowing treated seeds were significantly increased
compared to those in control, except for cold water treatment. The highest germination success (80%) was found in scarification
with sand paper, followed by 74% and 69% in immersion in H2SO4 and hot water treatment, respectively. Germination started on 8–11 days and completed on 20–21 days of the germination period
in all cases. Analysis of variance showed the significance difference in germination success among the treatments but no significance
difference in germination period among the treatment. Hot water treatment may be recommended on seed germination of the species
in rural Bangladesh. 相似文献
19.
Maman?Turjaman Yutaka?Tamai Hendrik?Segah Suwido Hester?Limin Joo Young?Cha Mitsuru?Osaki Keitaro?Tawaraya
Trees of the family Dipterocarpaceae are the dominant trees in Southeast Asian tropical forests where they play an important ecological role and are also important commercially. An experiment was conducted to determine the effect of ectomycorrhizal fungi on the growth of dipterocarp species in peat soils. Seedlings of Shorea pinanga were inoculated with spores of two ectomycorrhizal fungi, Pisolithus arhizus and Scleroderma sp. were grown in pots containing sterilized peat soil for 7 months. The percentage of ectomycorrhizal colonization on S. pinanga exceeded 86%. Colonization of S. pinanga roots by ectomycorrhizal fungi resulted in increased shoot height, stem diameter, number of leaves, and shoot fresh and dry weight. Survival rates of S. pinanga were greater for inoculated seedlings than control seedlings. These results suggest that inoculation of ectomycorrhizal fungi can improve the early growth of S. pinanga grown in tropical forests and that this technique will accelerate the rehabilitation of degraded dipterocarp forests. 相似文献
20.
Akram Taghizadeh Saroukolai Saeid Moharramipour Mohammad Hadi Meshkatalsadat 《Journal of pest science》2010,83(1):3-8
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