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1.
Roger Leakey Steve Fuller Tony Treloar Lesley Stevenson Denise Hunter Tio Nevenimo Jeffrey Binifa John Moxon 《Agroforestry Systems》2008,73(1):77-87
As part of a feasibility study of the commercialization potential of C. indicum nuts as Agroforestry Tree Products in Papua New Guinea, preliminary characterization studies have examined the tree-to-tree
variation in morphological traits (nut and kernel mass and kernel:nut ratio), as well as nutritional (carbohydrate, fat, protein,
sodium, vitamin E) and medicinal traits (anti-oxidant activity, anti-inflammatory activity and phenolic content) of kernels
from 18 to 72 trees in a small number of different villages of Papua New Guinea (East New Britain Province). There was continuous
variation in these traits indicating opportunities for multiple trait cultivar development targeted at food and pharmaceutical
markets. Certain traits, for example anti-inflammatory activity, in which tree-to-tree variation was highly significant, present
greater opportunities than others, such as saturated:unsaturated fatty acid ratio. This intraspecific variation was greater
within populations than between populations. The data presented has allowed the development of a strategy to domesticate C. indicum for cultivation in homegardens and cocoa–coconut agroforests, using a participatory approach aimed at the production of agroforestry
tree products (AFTPs) to empower small-holders and enhance their livelihoods and income. 相似文献
2.
3.
An understanding of the inter-relationships between the traits characterising tree-to-tree variation in fruits and kernels
is fundamental to the development of selected cultivars based on multiple trait selection. Using data from previously characterised
marula (Sclerocarya birrea) trees in Bushbuckridge, South Africa and North Central Region of Namibia, this study examines the relationships between
the different traits (fruit pulp, flesh/juice mass, and nut shell and kernel mass) as a means to determine the opportunities
to develop cultivars. Strong and highly significant relationships were found between fruit mass and pulp mass in trees from
South Africa and Namibia, indicating that size is a good predictor of fruit pulp production. However, fruit size is not a
good predictor of nut or kernel production, as there were weak relationships between fruit and nut and/or kernel mass, which
varied between sites and landuses. Generally, the relationships between fruit mass and kernel mass were weaker than between
fruit mass and nut mass. Relationships between kernel mass and shell mass were generally weak. The lack of strong relationships
between fruit and kernel mass does, however, imply that there are opportunities to identify trees with either big fruits/small
nuts for pulp production, or trees with large kernels in relatively small fruits for kernel oil production. However, within
fruits from the same tree, nuts could contain 0–4 kernels, indicating that even in trees with an inherent propensity for large
kernels, improved pollination may be required to maximise kernel mass through an increase in kernel number. Finally, the relationships
between percentage kernel oil content and the measured morphological traits were also very weak. The conclusions of these
results are that there is merit in identifying different combinations of traits for the selection of trees producing either
pulp or kernels. Consequently, fruit and kernel ‘ideotypes’ are presented as guides to the selection of elite trees for cultivar
development. These results have important implications for the domestication of the species as a producer of fruits or kernels
for food/beverages or cosmetic oils. 相似文献
4.
5.
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
6.
New initiatives in agroforestry are seeking to integrate into tropical farming systems indigenous trees whose products have
traditionally been gathered from natural forests. This is being done in order to provide marketable products from farms that
will generate cash for resource-poor rural and peri-urban households. This poverty-alleviating agroforestry strategy is at
the same time linked to one in which perennial, biologically diverse and complex mature-stage agroecosystems are developed
as sustainable alternatives to slash-and-burn agriculture.
One important component of this approach is the domestication of the local tree species that have commercial potential in
local, regional or even international markets. Because of the number of potential candidate species for domestication, one
crucial first step is the identification of priority species and the formulation of a domestication strategy that is appropriate
to the use, marketability and genetic potential of each species.
For most of these hitherto wild species little or no formal research has been carried out to assess their food value, potential
for genetic improvement or reproductive biology. To date their marketability can only be assessed by their position in the
local rural and urban marketplaces, since few have attracted international commercial interest. To meet the objective of poverty
alleviation, however, it is crucial that market expansion and creation are possible, hence for example it is important to
determine which marketable traits are amenable to genetic improvement. While some traits that are relatively easy to identify
do benefit the farmer, there are undoubtedly others that are important to the food, pharmaceutical or other industries that
require more sophisticated evaluation.
This paper presents the current thinking and strategies of ICRAF in this new area of work and draws on examples from our program.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
Ard G. Lengkeek Alice Muchugi Mwangi Caroline A. C. Agufa Joseph O. Ahenda Ian K. Dawson 《Agroforestry Systems》2006,67(3):293-300
It is possible that current tree domestication practices undertaken by farmers reduce the genetic base of tree resources on
farms, raising concerns regarding the productivity, sustainability and conservation value of agroforestry ecosystems. Here,
we assessed possible changes in genetic variation during domestication in the important and heavily utilised timber species,
Vitex fischeri Gürke (syn. Vitex keniensis), by comparing geographically proximate forest and farm material in central Kenya. Employing RAPD analysis, a total of 104
polymorphic markers revealed by five arbitrary primers were scored in a total of 65 individuals, 32 from forest and 33 from
farmland. Despite concerns of possible genetic erosion, forest and farm stands did not differ significantly in levels of genetic
variation, with H values of 0.278 and 0.269, respectively. However, Mantel tests did reveal greater geographically related associative genetic
structure among individuals in farm rather than forest material, with r
M values of 0.217 and 0.114, respectively. A more detailed analysis of structure suggested this could be due to local variation
in origin of some on-farm trees. Implications of data for the genetic management of V. fischeri stands during farmer-led tree domestication activities are discussed. At present, there appears little reason to reject on-farm
V. fischeri as a source of germplasm for future on-farm planting or for conservation purposes, although this situation may change and
will require monitoring. 相似文献
8.
Hiromi Mizunaga Shizuo Sako Yuri Nakao Yoshitaka Shimono 《Journal of Forest Research》2005,10(6):481-486
The refugee population of Fagus crenata in the Takakuma Mountains, Kyushu, Japan, represents the southern limit of this species' distribution area. Because this
population is the most exposed to the global warming effect, records of this population are likely to provide useful information
on the response of this species to global warming. The aim of this study was to record the present status of this valuable
population, enabling judgment of its sustainability. The density of successive F. crenata trees and saplings was low regardless of the coverage of dwarf bamboo. Moreover, the proportion of empty nuts observed was
considerably high, suggesting to be the likely major factor limiting recruitment of saplings or successors in this population.
Radial growth of F. crenata was shown to have been decreasing for the past 50 years, and there was a significantly negative correlation with the warmth
index. The decreasing growth rate and poor regenerative ability caused by the high proportion of empty nuts suggest the possibility
that this population will degrade further in the future, possibly being replaced by shrubs and small tree species. 相似文献
9.
Akira Ueda 《Journal of Forest Research》2000,5(1):21-29
A study of pre- and post-dispersal damage to the nuts of two beeches,Fagus crenata Blume andF. japonica Maxim., which masted simultaneously, was performed on a single site in Japan. Most insect damage to the nuts before dispersal
resulted from boring by lepidopteran larvae, and the level of attack was markedly higher onF. crenata than onF. japonica. Early nut growth ofF. crenata allowed these borers to act as the first attackers on the nuts. Conversely, late nut growth ofF. japonica delayed the attack of borers, and foliage feeders acted as the first attackers instead, chewing on nuts from the outside.
The low level of borer attacks on the nuts ofF. japonica in mast years was thought to have been caused by foliage feeders decreasing the amount of food resource available for later
attack by borers in lean years. This could then lead to a subsequent depression of the population of borers in mast years.
The proportion of nuts damaged by moth larvae was independent of the density of nuts for both beech species. Caching by vertebrates
was thought to be the most important factor in post-dispersal damage because the density of nuts of both beech species on
the forest floor in March was half the level measured using seed traps in the previous year. However, post-germination damage
caused by a fungus was also an important factor. The survival rate of the nuts (including current-year seedlings) in the year
after dispersal was independent of the density of dispersed sound nuts in the previous year for both beech species, with the
exception of one set of observations (forF. japonica in July).
This research was supported in part by a grant from the Japanese Ministry of Agriculture, Forestry and Fisheries. 相似文献
10.
Roger R.B. Leakey Zacharie Tchoundjeu Rognvald I. Smith Robert C. Munro Jean-Marie Fondoun Joseph Kengue Paul O. Anegbeh Alain R. Atangana Annabelle N. Waruhiu Ebenezer Asaah Cecilia Usoro Victoria Ukafor 《Agroforestry Systems》2004,60(2):101-111
Ten fruit and kernel traits were measured in 152 Irvingia gabonensis and 293 Dacryodes edulis trees from 6 villages in Cameroon and Nigeria. Frequency distribution curves were used to examine the range of variation
of each trait of each species in each village and aggregated into national and regional populations. There were differences
between the village sub-populations, with regard to the normality (e.g., mean kernel mass of D. edulis) or skewness (e.g., mean flesh depth of D. edulis) of the distribution curves and in the degree of separation between the individual village populations along the x axis,
resulting in the development of a bimodal distribution in the regional population. For all traits, populations of both species
differed significantly between countries, but only in D. edulis were there significant differences between the Cameroon populations. On the basis of the results of this study, D. edulis can be said to be virtually wild in Nigeria but semi-domesticated in Cameroon, while I. gabonensis is wild in Cameroon and semi-domesticated in Nigeria. These results are discussed with regard to a hypothesis that the range
and frequency of variation in the different populations can be used to identify five stages of domestication. From a comparison
of the frequency distribution curves of desirable versus undesirable traits, and statistically identifyable changes in skewness and kurtosis, it is concluded that as a result of
the farmers’ own efforts by truncated selection, D. edulis is between Stages 2 and 3 of domestication (with a 67% relative gain in flesh depth) in Cameroon, while I. gabonensis in Nigeria is at Stage 2 (with a 44% relative gain in flesh depth). In this study, genetic diversity seems to have been increased,
and not reduced, by domestication.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
11.
12.
世界松籽资源生产利用现状及我国松籽发展对策探讨 总被引:2,自引:1,他引:1
松籽是一种美味的非木质林产品, 全球有30多个松属物种可以生产可食用松籽, 但目前只有5个物种的松籽被用于商业生产。近年来, 国际松籽市场规模在不断扩大, 产品供不应求, 价格居高不下。我国是松籽生产及进出口大国, 年产量在2万t左右, 出口量占世界松籽贸易量的40%以上, 居首位, 但出口的松籽多数原产于俄罗斯。近几年俄罗斯国内消费量在不断增长, 加之俄罗斯远东及西伯利亚生产松籽的森林被大面积地砍伐破坏, 我国不可能长期依赖进口满足国内消费及出口需求。因此, 建议对我国果用松林的经济与生态重要性进行再评估, 并考虑起动相关研究, 挖掘潜力, 对生产松籽的松林实施园艺式高效经营或作为专门产业来管理。 相似文献
13.
L. G. García-Montero C. Pascual A. García-Abril J. García-Cañete 《Agroforestry Systems》2007,70(3):251-258
The Périgord black truffle (Tuber melanosporum Vittad.) can mycorrhize with rockroses (Cistus L.) in Mediterranean forests. These shrubs may be of interest for truffle cultivation as they produce early carpophores,
collaborate in tree mycorrhization and in the survival of Tuber melanosporum mycelium. However, there are very few quantitative studies on truffle production associated with Cistus. For this reason, we have carried out a study on the natural production of Tuber melanosporum associated with Cistus laurifolius L. in central Spain. An Anova test confirmed the existence of significant differences in carpophore production in four habitats,
with and without the presence of C. laurifolius. Twenty-one burns associated with C. laurifolius showed less significant production than the rest. We also confirmed that in 122 burns, Tuber melanosporum was always unequivocally associated with the root base of Quercus L. or Corylus L. trees. Similarly, five truffle-collectors confirmed that they had never found a single burn with carpophore production
associated exclusively with rockroses. It has also been statistically verified that many Cistus die in Tuber melanosporum burns, whereas in old burns with minimum carpophore production, a new colonization of young Cistus has been observed. This study also confirms that C. laurifolius mycorrhizes easily with Tuber melanosporum. We propose that Cistus laurifolius may act as transmitters of Tuber melanosporum, although they do not induce fruiting. Consequently, the commercial cultivation of Cistus laurifolius mycorrhized with Tuber melanosporum for production is not recommended in truffle culture. The results reported substantiate the negative observations in cultivations
of T. melanosporum with other Cistus species. 相似文献
14.
Budi H. Narendra James M. Roshetko Hesti L. Tata Elok Mulyoutami 《Small-Scale Forestry》2013,12(4):519-538
This paper provides an overview of a tree species prioritization study of underutilized tree species in a participatory tree domestication program for smallholders in Indonesia. The study was conducted in three villages of Nanggung sub-district, Bogor district via farmer surveys, focus group discussion, SWOT analysis and evaluation of markets and germplasm sources. Five priority species were identified: Manglietia glauca, Parkia speciosa, Durio zibethinus, Gmelina arborea and Sandoricum koetjape. These species are promising components of agroforestry systems to enhance smallholder livelihoods and can grow under the low management conditions common in smallholder systems. They represent indigenous and exotic tree types that produce timber, fruit or spices within the domestication continuum. Furthering the domestication and utilization of these species requires the identification and dissemination of available germplasm sources, the dissemination of high-quality germplasm and the development of farmer-friendly propagation and tree management practices. Also, as with most smallholder systems, the marketing practices for the products of these five species require improvement, starting with the production of reliable quantities of high quality tree products. 相似文献
15.
Susceptibility of common tree species in Sweden to Phytophthora cactorum,P. cambivora and P. plurivora
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In Sweden, invasive Phytophthora pathogens have been recognized as a growing threat to urban and production forests, calling for an urgent update of regeneration strategies for infested areas. Stem inoculation tests were performed to test the relative susceptibility of common conifer and broadleaved tree species Pinus sylvestris, Picea abies, Larix x eurolepis, Betula pendula, Quercus robur, Fagus sylvatica, Populus trichocarpa and Tilia cordata to the root pathogens Phytophthora cactorum, P. cambivora and P. plurivora commonly isolated from Swedish soils. Results indicate that all the species tested were susceptible and formed lesions following stem inoculation with all three Phytophthora species, but to varying degrees. Of particular interest are the high levels of susceptibility in P. trichocarpa to all three Phytophthora species compared to other tested tree species. 相似文献
16.
研究了位于印度加瓦尔海平面(950~1100m)上的亚热带森林的再生生长状况。对生长在不同方位(东、西、北、南)研究地的植被进行了定量分析。研究结果表明:宽叶榆绿木(Anogeissus latifolia)的树木、幼树和幼苗层在研究地点的所有方位显生长优势。长叶松(Pinusroxburghii)和毛白杨(Terminalia tomentosa)的树木、小树在研究地点的北部显生长优势。树木层的最高(380株·ha-1)和最低密度(260株·ha-1)分别出现在南坡和北坡。幼树的最高(1790株·ha-1)和最低密度(970株·ha-1)分别出现在东坡和西坡。树木和灌木层的多样性分别为0.846~1.710和1.943-2.847。与其它种的相比较(4%~33%),宽叶榆绿木(Anogeissus latifolia)的相对剪枝强度较高(45%-57%),此种是在北坡中最重要的树种。目前研究表明,如果不合理开采继续进行,宽叶榆绿木(Anogeissus latifolia)就有可能被其他种代替,在树种的成分和森林重建方面会发生剧烈的变化。人类活动的压力,地理方位和土壤营养已引起了树种的成分和森林重建方面的变化。 相似文献
17.
The success of tree plantings in agricultural landscapes within dry and variable rainfall regions is often below expectations.
The aims of this study were to investigate techniques for establishing a local native species (Eucalyptus pauciflora) and an exotic species (E. nitens) in the Midlands of Tasmania, a tree-denuded region that has been grazed for over 100 years in Australia. We established
trials at the Sorrel Springs and Woodland Park properties. We compared six establishment techniques: control; understorey
nurse planting; spot burn; mulch; tree-guard and; self-watering tree-guard. Three months, 1 and 6 years after planting we
measured tree height, health index and mortality. At Sorrell Springs tree-guarded treatments had greater height than other
treatments at year one, but there were no effects of treatment at year six on height, health or mortality. At Woodland Park
mulch, burn and tree-guarded treatments had greater height 1 and 6 years after planting. At year six tree-guarded treatments
had lower mortality than other treatments. At Sorrell Springs height of E. nitens was greater than E. pauciflora at year one but not at year six. At Woodland Park height of E. nitens was generally greater at year six but having almost double the incidence of mortality relative to E. pauciflora. We conclude that expensive tree-guarding is only warranted where high browse pressure is expected and that on such sites
species with tough leaves that are resistant to browsing should be considered. Further that in environments marginal for growing
trees, best practice establishment technique is generally as effective as additional treatments of understorey nurse planting,
spot burning or mulching. 相似文献
18.
Robert Sykes Bob Kodrzycki Gerald Tuskan Kirk Foutz Mark Davis 《Wood Science and Technology》2008,42(8):649-661
Clonal variability among trees has been studied and found to have profound effects on nearly all measured phenotypes. However,
when estimating wood properties it is important to consider variability within the tree. The position in which a tree is sampled
could have a large influence on biomass characterization. We looked at variability in lignin content as height increases and
as the number of rings from the pith increase in Populus species. Seven trees were destructively sampled; subsamples were obtained along a 2.4 m length of each stem and across increment
rings. All samples were analyzed by pyrolysis molecular beam mass spectroscopy to map the variability across sampling heights
and/or ring positions in lignin content. The results of this study indicate that when sampling a tree, there is more variability
from ring to ring than at different heights going up the stem. 相似文献
19.
《Southern Forests》2013,75(2):59-69
Forest tree improvement programs benefit from the emergence of new biotechnological strategies that complement plant developmental biology and discovery of genes associated with complex multigenic traits. Recently, significant progress has been made in the area of plant regeneration via somatic embryogenesis (SE) for economically important tree species (e.g. pines). These advances have opened up new scenarios for deployment of new high-performance clonally replicated planting stock to forest plantations and may also be a valuable tool for the development of efficient gene transfer techniques. Although high rates of plant propagation from axillary shoot proliferation can be achieved easily in many Eucalyptus species, even higher multiplication rates through SE have been recorded in other tree species. If the clonal propagation of Eucalyptus through SE proves to be an effective propagation method, it has the potential to meet the increasing industrial demands for high-quality uniform materials and to rapidly capture the benefits of breeding programs. Since 2002 a reproducible protocol for SE induction from mature zygotic embryos of E. globulus has been available. However, for SE to be useful in E. globulus improvement programs, the frequency of SE initiation, maturation, germination and acclimatisation needs to be improved and controlled. If this technology could be extended to elite germplasm, it would become an economically feasible tool for large-scale production and delivery of improved planting stock. This is one of the greatest current challenges in Eucalyptus tissue culture. In this review we update the most important aspects of SE in Eucalyptus with particular emphasis on E. globulus. We highlight both genetic control and the influence of different environmental factors in the SE process (e.g. medium composition, antioxidants, light and plant growth regulators), from induction to plant acclimatisation in both primary and secondary SE. 相似文献
20.
《Southern Forests》2013,75(3):183-193
Tree bark is commonly used for traditional medicine in southern Africa and further afield. Increasing demand and commercialisation have resulted in the overexploitation of many species, posing a major challenge to forest managers to develop mechanisms for sustainable resource use. An experimental bark harvesting research project was initiated in the southern Cape, South Africa, to inform best practices for bark harvesting based on tree response to bark stripping. The species selected for the study, Ocotea bullata, Curtisia dentata and Rapanea melanophloeos, are much sought after and well represented in southern Cape forests. The treatment entailed removing vertical strips of bark, 1 m in length and of different strip widths, covering the full range of tree size classes ≥10 cm DBH. The treatments were applied during two seasons, winter and summer. Evaluations were done every six months to assess tree response to bark stripping in terms of bark regrowth through phellogen edge and sheet development, and susceptibility to insect and fungal damage. The results show a differential response of tree species in terms of phellogen edge and sheet growth, as well as susceptibility to fungal and insect attack. Rapanea melanophloeos was the most vulnerable to fungal and insect damage and displayed little bark regrowth following wounding. Curtisia dentata showed best bark regrowth through sheet development. Only O. bullata, though, showed adequate bark regrowth (through edge development) to allow for sustainable strip harvesting. Bark regrowth is influenced by season of stripping, although this is difficult to define considering the wide range of environmental and other factors affecting tree response to bark removal. Smaller trees are more vulnerable to bark stripping, especially with a wide strip, with poorer bark regrowth than bigger trees. 相似文献