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1.
Naturalized cocoa populations originating from the Oyapok and Tanpok basins in French Guiana were studied for their technological
characters (bean count, fat content, purine content) and sensory characters (overall aroma intensity, cocoa flavour, acidity,
bitterness, astringency, fruity or floral tastes, aftertaste, etc.), along with three controls (Amelonado and Ecuadorian varieties).
The bean count in Guianan cocoa was higher than that of the controls, but it generally remained acceptable (below 100). Caffeine
content was much higher than that of the Amelonado control. The overall aroma intensity and cocoa flavour of the chocolates
made with the dry cocoa beans from Guianan trees were statistically superior to those of the industrial reference, the West
African Amelonado. The other criteria studied, particularly the fat content, did not reveal any significant differences from
the controls.
An erratum to this article is available at . 相似文献
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Random amplified polymorphic DNA (RAPD) and isozyme electrophoresis (IE) techniques were used to estimate the level of genetic
diversity in a sample of cacao germplasm existing at the International Cocoa Genebank, Trinidad. Twenty-six cocoa populations
represented by 459 cocoa genotypes were analysed using IE and 22 populations represented by 353 cocoa genotypes were analysed
using RAPD. Despite few differences in the classification of the populations, both techniques revealed three major groups:
the indigenous trees, the cultivated Trinitario and the cultivated trees from Ecuador. Two-thirds of the partitioned diversity
were found within populations and one-third between the populations, with both techniques. 相似文献
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Jorge Cunha Margarida Baleiras-Couto José P. Cunha Jorgete Banza Adelaide Soveral Luís C. Carneiro José E. Eiras-Dias 《Genetic Resources and Crop Evolution》2007,54(5):981-988
Wild populations of Vitis vinifera L.␣have been located in Portugal. Morphological characterization was carried out in three populations located in Alcácer
do Sal, Castelo Branco, and Montemor-o-Novo, and then compared using multivariate discriminant analysis. These populations
were from three different hydrological basins, therefore cross-pollination was not possible. It was verified that in each
population all plants were different. The data suggest that the frequency of female and male plants is rather variable in
wild populations. The morphology of the adult leaf, from the Alcácer do Sal population, had particular features when compared
with Castelo Branco and Montemor-o-Novo populations, which were more homogeneous. The length of teeth compared with width
at the end of the base, and the density of prostrate hairs between and on main veins (lower side) were the variables which
allowed the best discrimination among populations. 相似文献
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The impact of clonality on an endangered tree (Elaeocarpus williamsianus) in a fragmented rainforest
The occurrence and distribution of clonality in the endangered rainforest tree Elaeocarpus williamsianus (Elaeocarpaceae) was investigated using SSR and RAPD analyses for 170 apparent individual trees found across seven sites. The results obtained with the two molecular techniques were in complete agreement in showing that single clones are present in most of the E. williamsianus sites with two genets occurring at the largest and most adequately protected site. In addition, seed production, viability and germinability were determined for four of these populations. Fruit were produced in all four populations tested although sterile fruit were very common. Only two E. williamsianus trees representing different genets within the same site produced viable seed. The overall genetic diversity within E. williamsianus is much lower than expected and thus the potential for sexual reproduction has been significantly diminished. It is concluded that habitat fragmentation removed an existing balance between vegetative and sexual reproduction in this species. Such findings have added urgency to the management of this species which could include a reintroduction program incorporating the collation of all clones within selected sites. 相似文献
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Alessandra Maria Moreira Reis Dario Grattapaglia 《Genetic Resources and Crop Evolution》2004,51(5):529-538
RAPD markers were used to investigate the distribution of genetic variability in a germplasm collection of the dioecious tropical tree Aroeira (Myracrodruon urundeuva) composed of open pollinated maternal half-sib families collected from trees at least 300 meters apart and grouped in nine collection areas throughout its geographical range in Brazil. Open pollinated families from nearby trees from two natural populations were also included in the study. A Principal Coordinate Analysis (PCO) based on genetic similarities estimated with 83 RAPD markers showed no defined clustering among individuals from the same collection areas. However, a matrix correlation test showed low, but significant correlation between genetic and geographic distances (r = 0.17; p < 0.02). An AMOVA showed that 92% of the genetic variation is found within collection areas. Significant variation was found both between regions and between areas within regions although only 3.54 and 4.44% of the variation was found at these levels respectively. An AMOVA on the individuals from the two natural populations resulted in a pattern of distribution congruent to the one found for the collection areas, with 97% of variability within populations. An analysis of 10 open-pollinated half-sib families revealed that between 75% and 89% of the variability is contained within families, suggesting that seeds from one tree represent a significant proportion of the variability found in the population. These results indicate that, either for the establishment of in situ genetic reserves or for ex situ conservation, efforts should be directed to the conservation of several individual trees or collection of open pollinated seed families in a few distant sites. In addition, if resources are available to enlarge the genetic base of the existing collection, expeditions should prioritize collection sites located in areas at significant distances to those already sampled. 相似文献
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S. C. Debnath 《Genetic Resources and Crop Evolution》2007,54(3):509-517
Forty-three wild cranberry (Vaccinium macrocarpon Ait.) clones collected from four Canadian provinces and five cranberry cultivars were assessed for genetic variability by
using random amplified polymorphic DNA (RAPD)-PCR. Fourteen primers generated 161 polymorphic RAPD-PCR bands. A substantial
degree of genetic diversity was found among the wild cranberry collections. Cluster analysis by the unweighted pair-group
method with arithmetic averages (UPGMA) separated the wild clones and three cultivars into five main clusters, and identified
the two remaining cultivars as outliers. Furthermore, within four clusters, the genotypes tended to form sub-clusters that
were in agreement with the principal coordinate (PCO) analysis. Geographical distribution explained 10% of total variation
as revealed by analysis of molecular variance (AMOVA). The RAPD markers detected a sufficient degree of polymorphism to differentiate
among cranberry clones and cultivars, making this technology valuable for germplasm management and the more efficient choice
of parents in current cranberry breeding programs. 相似文献
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We investigated morphological evidence that might allow wild Pyrus spp. to be distinguished from cultivated material (Pyrus communis L.) in the North-eastern Iberian Peninsula. 134 pear trees were identified in the wild and characterized by 13 quantitative
and 13 qualitative leaf–shoot and fruit traits. The trees were visually classified into two preliminary groups of wild and
cultivated material and discriminant functions, based on a reference collection for allocating individuals to one of the groups,
were constructed. Both classifications were compared with a near-optimal numerical classification (the two-stage Ward-MLM
strategy) using two criteria. The visual assignment of trees allocated 60% of trees to the wild group and 40% to the cultivated
group. The overall discrepancy rate between the field classification and the discriminant analysis was low (17.4%). In general,
wild individuals had smaller leaves, shorter petioles and more rounded and smaller fruits than their cultivated counterparts.
They also had small-to-intermediate petiole widths, thorns on their shoots and straight or convex fruit profiles. However,
the Ward-MLM strategy always formed better groups, in terms of the two criteria used, in all the continuous and categorical
variables, for both leaf–shoot and fruit traits. Likewise, the agreement between classifications (discriminant analysis and
Ward-MLM strategy) was only partial, with some Ward-MLM groups composed of both wild and cultivated material in similar proportions.
This result suggests a limited success in identifying genuine wild individuals based on morphometric data, which can be ascribed
either to poor phenotypic diversity and lack of distinguishing traits among species or to widespread crossability and subsequent
development of hybrid/introgressant populations between wild and cultivated specimens. 相似文献
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Manuel Sanz Javier Pérez Jesús Pascual Javier Machín 《Journal of plant nutrition》2013,36(8):1697-1703
In populations of apple trees (Malus pumila Mill) affected by iron (Fe) chlorosis, the floral analyses permit to establish relationships between the Fe concentration in flowers and the chlorophyll content in leaves at 60 and 120 days after full bloom. The relationships between both parameters were highly significant with correlation coefficients of 0.603*** and 0.872***, respectively. As from previous research with peach trees, these high correlations permitted us to predict at a very early stage, the appearance of the Fe deficiency and its intensity. In our experimental conditions, the first visual symptoms of the Fe chlorosis appear in apple leaves with floral Fe concentrations below 310 ppm in dry matter. 相似文献
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R. Rivero A. Sønsteby O. M. Heide F. Måge S. F. Remberg 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(4):292-302
In order to assess to what degree the ongoing global warming has affected flowering time of apple trees in the Nordic climate, we studied flowering phenology of trees in an orchard in Southern Norway. Correlation analysis of a 70-year (1946–2016) data series for flowering time of the cultivar ‘Gravenstein’ revealed a close relationship of the flowering phenophase with April–May heat accumulation (r?=??0.98). Over the last 50-year period, flowering was advanced by 16 days in response to the temperature rises. Similarly, on average for 12 cultivars of varying earliness, flowering was advanced by 9 days over the latest 30-year period (1986–2016). Furthermore, the interrelationship between various phenological stages and floral morphogenesis of the same cultivars in the years 2013 and 2014 was studied, and related to flower-bud formation. The different stages of floral morphogenesis were identified, presented and used as a basis for assessment of flower-bud development in serial dissections. Floral initiation in spurs of actively growing trees took place in late July, approx. 8 weeks after full bloom, whereas in extension shoots, initiation took place after growth cessation in August, approximately 2 weeks later. Decreasing temperatures in mid-August coincided with the cessation of growth and floral initiation in extension shoots, suggesting that the processes may be causally related. The results show that, in the Nordic climate, the period between blooming and initiation of new floral primordia is considerably shorter than in warmer climates, suggesting that the period is only marginally long for completion of shoot growth, and hence, timely floral initiation. This may be an important reason for the irregular flowering and frequent incidences of alternate bearing in apple trees in the cool Nordic climate. The presented information can be useful for determination of the correct timing of flower and fruit thinning to counterbalance biennial bearing. 相似文献
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《CATENA》2003,50(2-4):401-414
Gullied and ungullied catchments in four areas of deeply weathered saprolite in the Middle Veld of Swaziland can be successfully separated (p<0.01) using discriminant analysis based on area and slope of their basin heads. The discriminant scores for the catchments indicate that those on the Manzini land system differ in their behaviour from those on the Lobamba land system. No differences exist within each land system with respect to land use when the basins are classified as arable, rangeland or mixed. The discriminant functions indicate that gullies on the Lobamba land system have developed by Hortonian overland flow whereas those on the Manzini land system should be attributed to subsurface processes. Since no evidence exists for subsurface activity, it is suggested that gullying on the Manzini land system has been more active and, though initiated by overland flow, has developed to a stage where seepage at the base of the saprolite is now the main process. Erosion control measures should be based on dense ground vegetation to reduce flow velocity on the Lobamba land system and deep-rooted vegetation with high evapotranspiration rates to reduce flow volumes on the Manzini land system. 相似文献
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S. N. Raina P. S. Ahuja R. K. Sharma S. C. Das P. Bhardwaj R. Negi V. Sharma S. S. Singh R. K. Sud R. K. Kalia V. Pandey J. Banik V. Razdan D. Sehgal T. H. Dar A. Kumar S. Bali V. Bhat S. Sharma B. M. Prasanna S. Goel M. S. Negi P. Vijayan S. B. Tripathi B. Bera M. Hazarika A. K. A. Mandal R. R. Kumar D. Vijayan S. Ramkumar B. R. Chowdhury S. S. Mandi 《Genetic Resources and Crop Evolution》2012,59(7):1527-1541
The most important evolutionary event in the success of commercial tea cultivation outside China in ~30 countries came about by the origin of India hybrid tea in India, derived from the extensive spontaneous hybridization that took place between the Assam type tea growing in the forest regions of Assam, North-East India and China type tea introduced from China in ~1875 to many regions of North-East India. The release of an enormous pool of vigorous and highly variable plants of India hybrid tea in North-East India was a significant step forward for the origin and evolution of tea as a highly successful crop plant. The 1,644 accessions and clones of India hybrid tea, representatives of known 15 morphotypes, were screened by 412 AFLP markers amplified by 7 AFLP primer pair combinations. All the 412 genetic loci were polymorphic across the 1,644 accessions and clones. The analysis was done with distance (PCoA and NJ) methods, and the STRUCTURE (Bayesian) model. Both PCoA and NJ analysis clustered 1,644 tea accessions and clones into six major groups with one group in each, constituted mostly by China hybrid, Assam China hybrid and Assam hybrid morphotypes, of distinct genetic identity. No group was exclusive for any particular morphotype. The accessions and clones belonging to morphotypes, Assam type, Assam hybrid, China hybrid and China Cambod were distributed in all the groups. It is the Assam type/Assam hybrid morphotypes which exhibit much broader genetic variability than in China type/China hybrid/Cambod type/Cambod hybrid morphotypes. The STRUCTURE analysis inferred 16 populations (K = 16), for which the greatest values of probability were obtained. Nine of the 16 clusters were constituted by the tea accessions and clones of ‘pure’ ancestry. The remaining clusters were of ‘mixed’ ancestry. This analysis provides evidence that the accessions and clones of the same morphotype are not always of same genetic ancestry structure. The tea accessions and clones obtained from outside North-East India shared the same groups (distance method) and clusters (STRUCTURE model) which were constituted by North-East India accessions. The present study also demonstrates very narrow genetic diversity in the commercial tea clones vis-à-vis the profound genetic diversity existing in the tea accessions. These clones were distributed in hardly two of the six groups in NJ tree. The identified 105 core accessions and clones, capturing 98% diversity, have their origin from almost all groups/subgroups of NJ tree. 相似文献
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Abstract. To assess the effect of different land uses on soil properties, five land use types (fallow, Gmelina , arable, secondary forest and cocoa plots) on a sandy loam Alfisol (Typic Kandiudalf) were compared in terms of surface (0–15 cm) soil pH, exchangeable acidity, K, Ca and Mg, extractable P, total N, organic matter, gravimetric moisture, temperature and bulk density. There were significant differences ( P ≤ 0.05- P ≤ 0.001) between the land use types for all the properties except exchangeable acidity and moisture. All the land use types differed significantly from each other in at least four properties. Fallow and secondary forest differed in nine properties, fallow and cocoa in seven and fallow and Gmelina in six. In terms of the number of properties with high variability (CV ≥ 35%), the order was arable, secondary forest and cocoa (4) > Gmelina (3) > fallow (1). 相似文献