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W. H. Ntundu S. A. Shillah W. Y. F. Marandu J. L. Christiansen 《Genetic Resources and Crop Evolution》2006,53(2):367-378
A field experiment was conducted in Tanzania for two seasons to assess the genetic diversity of bambara groundnut landraces
based on morphological characters. One hundred accessions collected from a wide range of agricultural zones in the country
were evaluated in a 10 × 10 triple lattice block design at Maruku station in Bukoba, Tanzania. For the qualitative characters
evaluated, considerable morphological variations were observed for growth habit, pod shape and pod colour. Quantitative morphological
characters such as peduncle length, number of leaves per plant, terminal leaflet width, terminal leaflet length, petiole length,
plant spread, plant length, pod width, seed length, seed width, number of pods per plant, shelling percentage and days to
50% flowering showed significant variation among accessions for the two test seasons. Multivariate analysis for 15 quantitative
morphological traits that showed significant variation indicated that the first four PCs with eigenvalues ≥1 accounted for
63.0 and 65.0% of the total variance among the accessions during the two test seasons, respectively. The most important loadings
for PC1 and PC2 for the two seasons were terminal leaflet width, terminal leaflet length, petiole length, plant spread, plant
height and pod length, pod width, seed length, seed width, numbers of pods per plant. Cluster analysis grouped bambara groundnut
accessions into three major groups with respect to their geographic origins. Based on this present study, bambara groundnut
landraces from Tanzania displayed a considerable diversity for morphological and agronomic traits useful for germplasm management
and utilization into crop improvement. 相似文献
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H. D. Upadhyaya K. N. Reddy C. L. L. Gowda Sube Singh 《Genetic Resources and Crop Evolution》2007,54(6):1167-1184
The pigeonpea core collection developed at ICRISAT genebank consists of 1,290 accessions from 53 countries. The core collection,
which includes selected lines in extra early, early, medium and late maturity groups was evaluated for 18 qualitative and
16 quantitative characters during the 2004 rainy season, to assess the phenotypic diversity and determine the relative importance
of different characters in evaluating pigeonpea germplasm accessions. The four maturity groups differed significantly for
all characters under study. The medium maturity group showed significantly higher mean number of primary, secondary and tertiary
branches, number of racemes, pod bearing length, pods per plant, shelling percent and plot seed yield. Late maturity group
showed significantly higher mean for leaf size, plant height, pod length, seeds per pod and 100-seed weight, indicating this
group as a good source of vegetable pigeonpea. Significant positive correlations were found between number of secondary branches
and pods per plant in extra early group (r = 0.756), late maturity group (r = 0.776) and entire core (r = 0.728) and between number of racemes and pods per plant in all maturity groups and entire core. Principal coordinate and
principal component analysis showed that seven qualitative and nine quantitative traits were important in explaining multivariate
polymorphism. The Shannon–Weaver diversity index (H′) varied for different maturity groups and traits. Phenotypic diversity, averaged over all the 16 characters, increases from
extra early group (0.36 ± 0.04) to late maturity group (0.42 ± 0.04) suggesting that medium and late maturity groups have
greater diversity compared to extra early and early maturity groups. 相似文献
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Ajaz A. Malik V. K. Vashisht Kuldeep Singh Abhishek Sharma D. K. Singh Hira Singh A. J. Monforte James D. McCreight Narinder P. S. Dhillon 《Genetic Resources and Crop Evolution》2014,61(6):1189-1208
We report here the first broad genetic characterization of farmer-developed landraces of melon (Cucumis melo L.) from the Indo-Gangetic plains of India, an area overlooked in previous melon genetic diversity analyses of Indian melon germplasm. Eighty-eight landraces from three melon Groups in two subspecies (C. melo subsp. agrestis Momordica Group, and C. melo subsp. melo Cantalupensis Group and Reticulatus Group) were collected from the four agro-ecological regions (six sub-regions) of two northern states of the Indo-Gangetic plains of India, Uttar Pradesh and Uttarakhand. Significant differences were found among the landraces and eight USA Reticulatus Group reference cultivars for 18 plant and fruit traits: no. of primary branches per plant, days to marketable maturity, sex expression, fruit shape, flesh colour, netting, no. of fruit per plant, fruit weight, shelf life, total soluble solids (°Bx), ascorbic acid (mg/100 g), titratable acidity (%), fruit length and diameter, seed cavity length and diameter, flesh thickness, and resistance to Cucumber mosaic virus. The three melon groups differed significantly for 10 of the plant and fruit traits. Cantalupensis Group and Reticulatus Group accessions were andromonoecious, and the Momordica Group was monoecious. Neighbour-joining (NJ) tree and factorial correspondence analysis (FCA) of simple sequence repeat loci also revealed a high level of genetic variability in this germplasm. The 96 melon genotypes clustered into five groups in the NJ tree analysis: the 16 Indian Reticulatus Group accessions and eight USA reference cultivars formed a distinct group; and the 60 Cantalupensis Group accessions clustered in four other groups with the 12 Momordica Group accessions in a distinct subgroup of one of the Cantalupensis groups. The FCA plot largely confirmed the NJ tree with three distinct groups, one for each melon group. The close affinity of the Indian and USA Reticulatus melons was not unexpected, but it is not clear whether it was inherent in the group and maintained as Reticulatus melons moved from India through Central Asia and Europe to North America, or the result of recent intercrossing of Indian landraces with the USA-derived cultivars and selection for a broad range of Reticulatus type melons. 相似文献
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Hari D. Upadhyaya K. N. Reddy C. L. L. Gowda S. N. Silim 《Genetic Resources and Crop Evolution》2007,54(8):1787-1795
Pigeonpea germplasm accessions collected from low (<500 m), medium (501–1000 m), high (1001–1500 m) and very high elevation
zones (>1500 m) of Kenya were evaluated for 15 agronomic traits and seed protein content at ICRISAT, Patancheru, India. There
were significant differences (P < 0.001) among elevation zones for the number of primary and secondary branches, days to 75% maturity, pod length, seeds per
pod, 100-seed weight and seed yield. Mean values indicated that the accessions from low elevation zone were significantly
different from those collected in higher elevation zones for early flowering and maturity, number of primary branches, pod
length, number of pods per plant, seeds per pod, 100-seed weight, seed yield and harvest index. None of the accessions collected
in Kenya belonged to extra early (<80 days to 50% flowering) and early (80–100 days to 50% flowering) maturity groups, as
defined by time to flowering at Patancheru, India. Mean diversity index based on all characters indicated that accessions
from the low elevation zone are more diverse than those from the higher elevation zones. Frequency distribution for trait
extremes indicated that the accessions from the low elevation zone were early to flower and mature, short statured, produced
more primary and secondary branches with high pod bearing length, long pods, more pods per plant, more seeds per pod, a high
seed yield and harvest index. Accessions from the very high elevation zone were late flowering, with a large number of tertiary
branches, large seeds and a high shelling percentage and could be a source for cold tolerance and the breeding of vegetable
types. Results suggest that the elevation of collection sites is therefore a very important determinant of variation patterns
of pigeonpea in Kenya. 相似文献
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The variability of 14 landraces belonging to a Madrilean village historically specialized on melon cultivation, Villaconejos,
was evaluated based on 58 quantitative and qualitative morphological traits. These landraces were compared to a reference
array composed of 14 accessions which represented the main varieties cultivated in Spanish fields. Individual data related
to plant, fruit, seed and phenology have been analysed using a multivariate analysis. This analysis showed intra- and inter-varietal
diversity, as emphasized the most discriminant morphological traits in order to define similarities. Villaconejos accessions
were morphologically distinct from the reference accessions (RA). Only the landraces belonging to Piel de Sapo market class
showed common morphological affinities with the RA, grouping with them. The majority of Villaconejos traditional varieties
clustered in five different groups, with no RA within, showing distinctive morphological singularities not described previously.
Two of these groups showed some particularities in fruit traits, which are appreciated as quality marks for Spanish consumers.
These results indicate that these accessions must be conserved as valuable genetic resources to enrich the Inodorus genetic
bases for future breeding proposes worldwide. Furthermore, it should be considered the opportunity of promoting their cultivation
under the shelter of a Protected Geographical Indication as a high quality melon. Finally, the discovering of such a high
variability presented in a very small area, gives a clue for focusing, with an elevated probability of success, future surveys
in similar ancestral European villages which in the past times, also supplied more populated cities with their farming products. 相似文献
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T. W. Eschholz P. Stamp R. Peter J. Leipner A. Hund 《Genetic Resources and Crop Evolution》2010,57(1):71-84
Between 1930 and 2003 with emphasis on the 1940s maize landraces (Zea mays L. ssp. mays) from all over Switzerland were collected for maintenance and further use in a new Swiss breeding program. The genetic relationship
and diversity among these accessions stored in the Swiss gene bank is largely unknown. Our hypothesis was that due to the
unique geographic, climatic, and cultural diversity in Switzerland a diverse population of maize landraces had developed over
the past three centuries. The aims were to characterize the genetic diversity of the Swiss landraces and their genetic relationship
with accessions from neighbouring regions as well as reviewing their history, collection, and maintenance. The characterization
and grouping was based on analyses with ten microsatellite markers. Geographic, cultural, and climatic conditions explained
a division in two distinct groups of accessions. One group consisted of landraces collected in the southern parts of Switzerland.
This group was related to the Italian Orange Flints. The other group contained accessions from northern Switzerland which
were related to Northern European Flints in particular German Flints. Historic evidence was found for a frequent exchange
of landraces within the country resulting in a lack of region-specific or landrace-specific genetic groups. The relatively
large separation between the accessions, indicated by high F
ST (0.42), might be explained partly by a bottleneck during the collection and maintenance phase as well as by geographical
and cultural separation of north and south of the country. Due to the high genetic diversity, the accessions here are a potential
resource for broadening the European flint pool. 相似文献
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Pigeonpea is an important pulse crop grown by smallholder farmers in the semi-arid tropics. Most of the pigeonpea cultivars
grown to date are selections from the landraces, with a narrow genetic base. With the expansion of the crop to newer areas,
problems of local importance are to be addressed. Hence, an economically feasible and faster germplasm evaluation mechanism,
such as a core collection, is required. This article describes the development of core collection from 12,153 pigeonpea accessions
collected from 56 countries and maintained at ICRISAT, Patancheru, India. The germplasm accessions from 56 countries were
placed under 14 clusters based primarily on geographic origin. Data on 14 qualitative morphological traits were used for cluster
formation by Ward’s method. From each cluster ≈10% accessions were randomly selected to constitute a core collection comprising
1290 accessions. Mean comparisons using Newman–Keuls test, variances’ comparisons by Levene’s test, and comparison of frequency
distribution by χ2-test indicated that the core collection was similar to that of the entire collection for various traits and the genetic variability
available in the entire collection is preserved in the core collection. The Shannon–Weaver diversity index for different traits
was also similar for both entire and core collection. All the important phenotypic associations between different traits available
in the entire collection were preserved in the core collection. The core collection constituted in the present study facilitates
identification of useful traits economically and expeditiously for use in pigeonpea improvement. 相似文献
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Ardeshir B. Damania Luciano Pecetti Calvin O. Qualset Bilal O. Humeid 《Genetic Resources and Crop Evolution》1996,43(5):409-422
Summary A collection of 2,420 accessions derived from single-spike population samples of durum wheat landraces collected in 1984 from 172 sites in 28 provinces in Turkey was evaluated for nine adaptive traits at the ICARDA research station at Tel Hadya, near Aleppo, Syria. Differentiation of these accessions among provinces was found for number of days to heading, maturity, grain-filling days, as well as for plant height, peduncle length, number of spikelets per spike, spike length, awn length, and kernel weight. The first three canonical variables accounted for 90% of the total variance. Canonical analysis also revealed significant correlations to province mean temperatures, altitude, latitude, and length of the growing season, but not with total seasonal rainfall. Eight distinct groups of provinces were identified by cluster analysis. These clusters had both geographical orientation to eastern and western Turkey and to agroecological zonation for clusters having both eastern and western provinces. Accessions were found with high kernel weight, early heading and maturity, and awnless spikes which could be utilized in crop improvement programs targeted at either favorable or stressed environments. 相似文献
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S. Al Khanjari K. Hammer A. Buerkert M. S. Röder 《Genetic Resources and Crop Evolution》2007,54(7):1407-1417
For millennia, wheat (Triticum spp.) has been grown in traditional aflaj-irrigation systems of remote mountain oases in Oman. However, little is known about
the diversity of the ancient landraces used. Given recent reports about the occurrence of novel germplasm in such material,
the objective of this study was to evaluate the genetic diversity of hexaploid wheat (Triticum aestivum L.) landraces in relation to their geographic origin using microsatellites. The collection covered most of the cultivation
areas in northern Oman where wheat landraces are growing. Total genomic DNA was extracted from six pooled plants representing
each accession. A total of 161 wheat accessions were assayed using 35 microsatellite loci in which a total of 305 polymorphic
bands were recorded for the 35 microsatellites. The polymorphic information content (PIC) across the 35 microsatellite loci
ranged from 0.02 to 0.89 with an average of 0.50. A heterozygosity percentage value of 9.09 was determined and the highest
level recorded for accessions from the Batinah district. Rare alleles averaged 1.85 with the highest value being from the
Dakhilia district. The results indicated a significant correlation between gene diversity and number of alleles across districts.
The correlation coefficient between these two variables over the 35 loci was 0.657, whereby correlation coefficients of 0.718,
0.706, 0.657 and 0.651, respectively, were found for the Batinah, Dhahira, Dakhilia and Sharqia materials. Genetic distances
indicated that all landraces were closely related. The cluster analysis discriminated most of the landraces accessions. However,
it failed to achieve region-specific groupings of landraces. The present study demonstrated the presence of high diversity
in Omani landraces and also indicated the effectiveness of microsatellites to describe it. 相似文献
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Morphological spike diversity of Omani wheat 总被引:2,自引:2,他引:0
S. Al Khanjari A. A. Filatenko K. Hammer A. Buerkert 《Genetic Resources and Crop Evolution》2008,55(8):1185-1195
Little is known about the diversity of field crops in Oman. The objective of this study therefore was to characterize wheat
accessions from this country using individual spikes collected from different wheat cultivation areas. The phenotypic assessment
of 15 qualitative and 17 quantitative characters showed variations among Omani wheat landraces. The standardized phenotypic
diversity index (H′) was with 0.66 higher for quantitative characters than for qualitative characters (0.52) in tetraploid
wheats and with 0.63 and 0.62, respectively, in hexaploid wheats. Overall, the morphological data revealed a surprisingly
high diversity among landraces and showed that simple morphological characters can be used for an effective characterization
of diversity in Omani wheat. 相似文献
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Gemechu Keneni Mussa Jarso Tezera Wolabu Getnet Dino 《Genetic Resources and Crop Evolution》2005,52(5):539-549
An experiment was conducted in 2001 at Holetta and Kulumsa, Ethiopia, to study the extent and pattern of genetic diversity
in Ethiopian field pea (Pisum sativum L.) landraces. One hundred forty-eight germplasm accessions were grown in an alpha lattice design with 2 replications. Data
on 12 traits were collected and analyzed. Differences among the accessions were significant for most of the traits (except
number of seeds/ pod) at each location even though differences pooled over location were mostly non-significant. The accessions
were grouped into five clusters of different sizes. Accessions from the southern part of the country (Arsi) distributed overall
clusters while those from the northern half (North and South Wello, North Gonder and North Shewa) fell into clusters C1 to C3. Cumulative effects of a number of characters dictated differentiation of the accessions into clusters. There was no definite
relationship between geographic diversity and genetic diversity as overlapping was encountered in clustering pattern among
accessions from different parts of the country. Accessions from different regions might have similar genetic background and
those from the same origin might also have different genetic background. Therefore, geographic diversity should not necessarily
be used as an index of genetic diversity and parental selection should be based on a systematic study of genetic diversity
in a specific population. Genetic distances among most of the clusters were significant that crosses between parents selected
out of them are expected to generate desirable genetic recombination. Selection should also consider the special advantages
of each cluster and each accession within a cluster. Future germplasm collection, conservation and breeding efforts should
focus not only on inter-regional diversity but also on intra-regional diversity. 相似文献