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1.
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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Tiny Motlhaodi Mulatu Geleta Stephen Chite Moneim Fatih Rodomiro Ortiz Tomas Bryngelsson 《Genetic Resources and Crop Evolution》2017,64(3):599-610
Cultivated sorghum [Sorghum bicolor (L.) Moench] is an important food security crop in the semi-arid regions of the world including Asia and Africa. Its genetic diversity is contained mostly in traditional varieties and modern cultivars used by farmers. In this study, agro-morphological traits and molecular markers were used to assess genetic diversity in 22 accessions of cultivated sorghum from five countries (Botswana, Namibia, Swaziland, Zambia and Zimbabwe) in the Southern African Development Community (SADC) region. The study revealed a significant variation among 22 accessions in both qualitative and quantitative morphological traits, indicating the accessions’ promising potential as breeding material. For molecular analysis, 11 microsatellite primer-pairs were used, and generated a total of 70 alleles across 20 accessions. Analysis of molecular variance revealed a high level of genetic variation; 67 % among the accessions and 10 % among the five countries. The patterns of genetic diversity and the relationships observed in this study should provide insights for genetic resource conservation and utilization of sorghum germplasm in the SADC region. 相似文献
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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
6.
Eleven accessions of an under-utilized legume, Mucuna pruriens (L.) DC. var. utilis (Wall. ex Wight) Baker ex Burck (velvet bean) were collected from four districts of South India and their agronomic characters
were evaluated. The vegetative growth characters such as the germination percentage, plant height, number of leaves and branches
per plant were recorded. The yield based characters such as the number of clusters/plant (4–14), number of flowers/cluster
(3–15) and the fertility index (66–91%) were observed. The seed yield reaches 2.9–6.9 t/ha. The number of seeds per pod, seed
weight and the seed recovery percentage were also calculated. The level of diversity in the agrobotanical traits of velvet
bean observed in the present study could be of interest in a breeding programme. 相似文献
7.
K. M. McCormick Robert Michael Norton H. A. Eagles 《Genetic Resources and Crop Evolution》2009,56(5):651-661
Fenugreek (Trigonella foenum-graecum L.) is a minor crop in the Wimmera region of south-eastern Australia. Limited studies have been in the past and these have been
on few accessions. This paper describes the use of quantitative and qualitative analyses to determine the main traits associated
with seed yield of fenugreek and to identify accessions suitable for commercial production. Phenotypic correlation analysis
and simple graphical analysis on a population of fenugreek accessions grown in 1998 and 1999 were used to determine important
traits associated with yield. Traits important for yield were early vigour, growth habit, flowering date, end of flowering
date, biomass at late flowering and harvest index. Yield per plant and seed weight were also important. Other traits considered
important for commercial success included machine harvestability, and bacterial blight resistance. Four accessions (A150118,
A150147, A150265, and A150292) were selected as cultivars for commercial release. Although all originating from latitudes
>30°, the accession were from different locations and were highly diverse in plant type and phenotypic characteristics. This
diversity could be exploited in future breeding programs. 相似文献
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Alireza Pour-Aboughadareh Mostafa Mahmoudi Mohammad Moghaddam Jafar Ahmadi Ali Ashraf Mehrabi Seyed Siamak Alavikia 《Genetic Resources and Crop Evolution》2017,64(3):545-556
Genetic erosion in cultivated wheat provides a good reason for studying genetic diversity in crop wild relatives. In the present study, genetic diversity of 32 accessions belonging to T. boeoticum species collected from different parts of Iran were evaluated using 13 morphological traits as well as ten inter-simple sequence repeat primers. Statistical analysis for morphological traits showed significant differences among accessions (except number of fertile tillers and total tillers per plant). In principal component analysis, the first three PCA showed 82.65 % of the total morphological variation. Based on the morphological traits, accessions were separated into two main groups by cluster analysis. In molecular analysis, polymerase chain reactions amplified 105 DNA fragments, out of which, 95 (90.47 %) were polymorphic. From geographic perspective, the accessions sampled from western and southwestern of Iran showed the highest and lowest polymorphism, respectively. However, the maximum values of effective number of alleles (Ne), Nei’s gene diversity (He) and Shannon’s information index (I) was related to accessions collected from NW regions. Also, according to cluster analysis and PCoA plot genetic diversity was not related to geographical distribution. Overall, our results revealed a remarkable level of genetic diversity among studied Iranian T. boeoticum accessions; especially accessions collected from Kermanshah and Lorestan provinces, which can be of interest for future breeding programs. So, conservation of germplasm of these areas is recommended. 相似文献
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A survey was undertaken in two valleys of the Bumthang area in Central Bhutan to study the morphological diversity, farmers’
knowledge, management practices, yield and income generation potential of the neglected Himalayan Pear (Pyrus pashia Hamilton ex D. Don). For this study a total of 148 Pyrus pashia accessions were collected and 103 households interviewed. Three quantitative and 14 qualitative traits such as colour, size,
shape and texture of fruits and tree habit were used for morphological characterization of the accessions. The results demonstrated
a high morphological diversity within the P. pashia trees. Fruit shape varied widely from globose to pyriform, fruit skin colour from light yellow and glossy to brown and dull.
The observed diversity is likely due to the fact that under farmers’ conditions trees are propagated through seedlings rather
than by grafting. None of the characters were specific and correlated with region or altitude. Distinct local cultivars with
specific characters were absent making it impossible to group the pears morphologically. Interviews revealed low numbers of
trees per farmers, lacking marketability of the fruits and farmers’ subsequent preference for improved varieties as major
obstacles for the in situ preservation of biodiversity in P. pashia in this area. 相似文献
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Asfaw Adugna Allison A. Snow Patty M. Sweeney Endashaw Bekele Evans Mutegi 《Genetic Resources and Crop Evolution》2013,60(4):1313-1328
In situ population studies of wild relatives of crops are crucial for the conservation of plant genetic resources, especially in regions with high genetic diversity and a risk of local extinction. Ethiopia is the center of origin for sorghum, yet little is known about the genetic structure of extant wild populations. Using 9 Simple Sequence Repeat loci, we characterized 19 wild populations from five regions, 8 local cultivar populations from three regions, and 10 wild sorghum accessions from several African countries. To our knowledge, this is the most comprehensive study to date of in situ wild sorghum populations in Africa. Genetic diversity corrected for sample size was significantly greater in the wild populations in situ than in local cultivars or the accessions. Approximately 41 % of the genetic variation in the wild plants was partitioned among populations, indicating a high degree of differentiation and potential value for germplasm conservation, and the average number of migrants (Nm) per generation was 0.43. Cluster analyses showed that some wild populations were grouped by geographic region, whereas others were not, presumably due to long-distance seed movement. Four wild populations from disjunct regions formed a unique cluster with an Ethiopian accession of subsp. drummondii and probably represent a weedy race. STRUCTURE and other analyses detected evidence for crop-wild hybridization, consistent with previous molecular marker studies in Kenya, Mali, and Cameroon. In summary, in situ wild sorghum populations in Ethiopia harbor substantial genetic diversity and differentiation, despite their close proximity to conspecific cultivars in this crop/wild/weedy complex. 相似文献
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M. Fergany Balvir Kaur A. J. Monforte M. Pitrat C. Rys H. Lecoq N. P. S. Dhillon S. S. Dhaliwal 《Genetic Resources and Crop Evolution》2011,58(2):225-243
We present here the first comprehensive genetic characterization of melon landraces from the humid tropics of southern India.
The genetic diversity among 50 melon landraces collected from 3 agro-ecological regions of southern India (6 agro-ecological
sub-regions) was assessed by variation at 17 SSR loci, morphological traits of plant habit and fruit, 2 yield-associated traits,
pest and disease resistance, biochemical composition (ascorbic acid, carotenoids, titrable acidity) and mineral content (P,
K, Fe, Zn). Differences among accessions were observed in plant and fruit traits. Melon germplasm with high titrable acidity,
higher than average amounts of mineral content and resistance to Cucumber mosaic virus, Zucchini yellow mosaic virus, powdery
mildew (races 1, 2, 3, 5), Fusarium wilt (races 1, 2), Aphis gossypii and leafminer was recorded in the collection. A high level of genetic variability in melon germplasm was suggested by the
SSR analysis. Comparative analysis using SSRs of the genetic variability between Indian melons from north, south, and east
regions and reference accessions of melon from Spain, France, Japan, Korea, Iraq, Zambia showed regional differentiation between
Indian melon accessions and that Indian germplasm was weakly related to the melon accessions from other parts of the world,
suggesting that an important portion of the genetic variability found within this melon collection has not been used yet for
the development of new cultivars. Additional collections of acidulus melon germplasm should be made in southern India and adequate management of this important genetic resource is clearly a
necessity. 相似文献
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A. P. Agre R. Bhattacharjee I. Y. Rabbi O. A. Alaba N. N. Unachukwu M. A. T. Ayenan Y. L. Loko G. J. Bauchet A. Dansi 《Genetic Resources and Crop Evolution》2018,65(2):513-525
Cassava (Manihot esculenta Crantz) is an important food security crop or resource for poor rural communities particularly in Africa. The crop’s ability to produce high yields even under poor conditions and storability of its roots underground for longer periods or until needed makes it a model ‘food security crop’. In Benin Republic, cassava has been recognized as one of the major crop contributing towards dynamic value chains generating incomes for small-holder farmers. The crop is grown all over the country, however, the increased production are mainly recorded from far south and central parts of the country. Genetic improvement of cassava in Benin Republic is limited because of poor knowledge of genetic diversity present within the country. The main objective of this study was to assess the genetic diversity and relationships among elite cassava varieties collected from different regions of Benin using fluorescently labelled simple sequence repeat (SSR) markers and to compare the results with farmer’s knowledge and morphological traits. A total of 96 cultivars collected from major cassava growing areas such as Southern and Central Benin were classified into 24 different groups using farmers’ knowledge, while classification based on 18 morphological traits resulted in five groups. In total, sixteen SSR markers were tested for molecular analysis of the ninety-six cassava varieties. Among the sixteen, twelve SSR markers gave good banding pattern and were used to genotype the varieties. An average of 3.58 and 0.47 for number of alleles and polymorphism information content respectively was observed. The observed heterozygosity (Ho) ranged from 0.23 to 1.0 with an average of 0.66 indicating moderate level of diversity among the cultivars. Based on the proportion of shared alleles and hierarchical clustering, the 96 elite cassava varieties were classified as 74 unique varieties. Principal component analysis and analysis of molecular variance revealed no significant variation between the regions thus, explaining regular exchange of planting materials among cassava farmers across various regions. The moderate level of genetic diversity in famer’s field, revealed in the present study, is a good indication of the need for broadening the genetic base of cassava in Benin Republic and establishing a formal breeding program in the country. 相似文献
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Oz Barazani Einav Mayzlish-Gati Dikla Lifshitz Rivka Hadas Alexandra Keren-Keiserman Sivan Golan Tomer Faraj Alon Singer Andrey Beerman Avi Perevolotsky 《Genetic Resources and Crop Evolution》2017,64(1):1-5
The ex situ collection of the Israel Plant Gene Bank (IGB) aims to encompass the rich local flora and its genetic diversity with an emphasis on crop wild relatives. However, to properly establish a core collection, collection efforts must be prioritized and strategized. We previously classified local plant genetic resources into four priority groups that assisted in strategizing the collection activities. The following years of intensive collection activity yielded over 4200 banked accessions. However, these do not necessarily represent the distribution range of the target species for collection (TSC) and consequently, their genetic diversity. To best cover the latter, the collecting area was divided into botanical districts and the magnitude of the collection was determined according to prioritization group, e.g., a wild relative of an agricultural crop with a vast distribution range should be represented by a larger number of banked accessions than one with a smaller range. Continuous evaluation of specific needs shapes the collection scheme of the IGB to maximize collection efforts, better represent the presumed genetic diversity of TSC, and establish its core collection. 相似文献
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S. Boucheffa M. M. Miazzi V. di Rienzo G. Mangini V. Fanelli A. Tamendjari D. Pignone C. Montemurro 《Genetic Resources and Crop Evolution》2017,64(2):379-390
The present work was aimed at assessing the genetic diversity of 42 local cultivars and oleaster genotypes from the area of Bejaia in Algeria. Fifteen highly polymorphic Simple Sequence Repeat markers were evaluated and proved to be very informative, producing a total number of 160 alleles with an average value of 10.7 per locus; the SSRs DCA09 and DCA16 were the most informative, distinguishing 17 and 19 genotypes, respectively. Phylogenetic and population structure analysis split the accessions in two main groups corresponding to most of oleasters and most of traditional varieties, respectively. Interestingly, ten traditional varieties resulted strictly related to the oleasters, indicating hybridization between the two botanical varieties. Genetic parameters and private alleles of groups confirmed this observation and indicated a wide genetic variability in Algerian olive germplasm. The results suggest the need to preserve and characterize this germplasm in order to limit the risk of losing potential important genetic traits present in the crop wild relatives. 相似文献
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Nasab K. Rawashdeh Nasri I. Haddad Mohamad M. Al-Ajlouni Munir A. Turk 《Genetic Resources and Crop Evolution》2007,54(1):129-138
Durum wheat landrace genotypes are disappearing from the main wheat areas in Jordan, because of spreading of new uniform cultivars
and the serious reduction in wheat cultivation. This study was conducted to evaluate genetic diversity in durum wheat landraces
from Jordan and to identify desirable agronomic traits. Landraces were collected from two target areas: Ajloun and Karak.
The collected material was grown under rainfed conditions using an augmented design with five blocks and four repeated check
cultivars. Data were collected for 14 morphological and agronomic traits. Phenotypic diversity index (H′) was estimated, and
the relationships among accessions were measured using cluster analysis and dendrogram similarity matrix. The results revealed
the presence of a wide range of variability among landraces., which possess high levels of variability for biological yield,
fertile tillers, number of seeds per spike, seed weight per spike and weight of 1000 seeds. These landraces must be considered
as a reservoir of genes that plant breeders need in their wheat improvement programs and should be conserved both ex situ and in situ. 相似文献
20.
Phenotypic diversity was assessed for quantitative and qualitative traits in a salt-tolerant subset of the international safflower
(Carthamus tinctorius L.) germplasm collection originating from 11 countries in three regions (Central Asia, Southwest Asia and Africa) of the
Middle East. Phenotypically, the germplasm, among and within regions, was highly variable, especially for rosette- and yield-related
traits. Frequency of desirable variants of seven agronomically important traits ranged from 14% for long rosette period to
50% for no or few spines. Level of population differentiation was high for number of capitula per plant (30%), whereas most
traits partitioned their diversity (82–87%) within populations. Region-specific nonrandom associations among sets of qualitative
traits and the existence of broad morphological and phenotypic diversity in this germplasm were supported by the large number
of log-linear models needed to describe qualitative trait associations, the high number of principal components needed to
account for total variability, and the low discriminatory power of phenotypic traits among germplasm from regions and countries
in the Middle East. These results suggest that adaptation of the species to the wide spatial and temporal variation in the
Middle East resulted in a multitude of ecotypes and in enormous amount of local variation. A multivariate selection criterion
for high biological and seed yield, long rosette period and no or few spines identified five accessions from Southwest Asia
that can be introduced into subsistence farming systems as a multipurpose crop under saline agriculture. 相似文献