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1.
Rice is the principal crop of northeastern region of India, where a considerable range of diversity exists. The germplasm
collection has also unfold the occurrence of large number of rice landraces in the region. Between 1985 and 2002, a total
2639 accessions of rice germplasms including their wild relatives have been collected. Most of these germplasm material have
been conserved in the National Gene Bank, New Delhi following their necessary characterization and evaluation. With the establishment
of the Regional Gene Bank Module with medium-term storage facilities (6–7°C with 40–45% relative humidity) at Barapani, Meghalaya,
the rice germplasm conservation (ex situ) have been initiated in the region. 相似文献
2.
J. Martínez-Castillo L. Camacho-Pérez J. Coello-Coello R. Andueza-Noh 《Genetic Resources and Crop Evolution》2012,59(2):191-204
Genetic erosion has been evaluated at the landrace level in the past, principally because the loss of landraces is believed
to generate erosion at the allelic level; however, few studies had tested this hypothesis in the crop’s centers of diversity
and domestication. Using microsatellite markers, we analyzed for genetic erosion in lima bean (Phaseolus lunatus) landraces over time in samples collected in 1979 and in 2007 in northeast Campeche, in the Yucatan peninsula, Mexico, an
important diversity center and part of the putative domestication area for this crop. We found that the lima bean genetic
pool from 1979 had a higher genetic diversity than the one for the 2007 pool (Nei’s diversity, H = 0.18 and 0.05, respectively). Although this result could not to be explained using a bottleneck analysis, a cluster analysis
showed that the alleles present in 1979 were not the same as those found in 2007, indicating an allelic displacement in the
genetic pool of the lima bean landraces in the last 30 years. This displacement could be due to the introduction of improved
varieties or landraces, resulting in a displacement of local varieties or to changes in the Mayan criteria for selection of
germplasm or both. This study showed that the loss of landraces can generate both quantitative and qualitative changes in
the genetic pool of the domesticated species. Such changes are very important to consider when planning ex situ and in situ programs to conserve crop diversity in their domestication areas. 相似文献
3.
M. W. Farnham E. H. Davis J. T. Morgan J. P. Smith 《Genetic Resources and Crop Evolution》2008,55(6):797-801
A common garden crop grown in the coastal plain region of North and South Carolina (United States) is the non-heading, leafy
green type of Brassica oleracea L. known as collard (B. oleracea L. subsp. oleracea convar. acephala (DC.) Alef. var. viridis L.). Predominantly a fall and winter vegetable in this region, collard is often the only green planting to be found in the
yard or garden of a rural home during these cool seasons. Historically, the traditional collard patch and even commercial
fields were planted with unique varieties perpetuated by individual seed savers, and collectively, the regional diversity
for this crop was probably very significant for well over a century. Genetic erosion of this collard germplasm pool has been
severe in recent decades as commercial hybrids have been adopted by both large-scale producers and home gardeners. Although
a significant number of collard landraces are being perpetuated to this day, existing diversity among landraces still grown
in the region is now in the hands of an aging population of seed savers who maintain germplasm through on-farm preservation.
From 2003 to 2006, we explored the coastal plain region of North and South Carolina in search of collard gardens containing
traditional landraces. Exploration trips were conducted mid-winter to early spring. About 90 samples of collard were obtained
from seed savers during the course of this exploration. Observations of morphological differences of these landraces indicate
that significant diversity exists in this group. Obtained landraces are being deposited into the U.S. plant introduction collection
and will be available for future use. This preserved collection could prove to be an important new source of genes for B. oleracea improvement. 相似文献
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Angela R. Piergiovanni 《Genetic Resources and Crop Evolution》2013,60(1):325-333
The increasing consumers’ request for new speciality wheat derivatives and the possible widening of marketing opportunities is giving to both landraces and old varieties, new chance of on farm survival providing a low cost way to safeguard these important genetic resources. A farmer’s consortium acting in north-western Italy, is attempting the introduction of some old bread wheat landraces in marginal environments of Piedmont and Liguria regions. The reason of this attempt is the local market demand of old bread varieties suitable for the preparation of traditional cakes and biscuits. Three Italian bread wheat landraces, a mixture of durum and bread wheat landraces and three modern varieties were evaluated. The entries were cropped in Val Borbera and Val d’Aveto (Piedmont and Liguria region, respectively) in the same growing season (2009–2010). The high variation of gliadin profile detected within the landraces indicates that all have retained the genetic heterogeneity typical of the old wheat landraces. In consequence of the health-promoting effects of whole grain consumption, eleven nutritional and technological traits of whole flours were investigated. The analysis of collected data revealed appreciable differences among the flours obtained from the landraces and the modern varieties. These differences can be mainly attributed to the intensive breeding carried out on bread wheat in the last century. The results of this study suggest that the old bread wheat landraces could have good chance of survive on farm when their characteristics fulfil the requirements of local communities. 相似文献
8.
Zhiyuan Xiong Shujie Zhang Yunyue Wang Brian V. Ford-Lloyd Min Tu Xin Jin Yue Wu Huanxin Yan Xiao Yang Ping Liu Bao-Rong Lu 《Genetic Resources and Crop Evolution》2010,57(6):891-902
Indica–japonica variation represents the most significant genetic differentiation in Asian cultivated rice (Oryza sativa L. subsp. indica Kato or subsp. japonica Kato). Understanding the differentiation and distribution patterns of cultivated rice along altitude gradients will facilitate strategic utilization and conservation of rice germplasm from mountainous regions. In this study, we analyzed 203 varieties and 14 wild accessions of rice collected from localities across an altitude gradient between 450 and 2,350 m above sea level in Yunnan, China, applying the “InDel molecular index” developed recently. Results from PCA of the InDel data demonstrated significant genetic differentiation of rice varieties from Yunnan into indica and japonica types. A few cultivars and nearly all wild rice accessions showed only moderate or no differentiation. Further analyses demonstrated a clear distribution pattern of the rice varieties in the mountainous region: indica varieties were grown across the entire altitude gradient in the sampling areas, but most japonica varieties were found above 1,400 m. These results clearly indicated that indica rice could be cultivated in areas at much higher altitudes than those categorized by the traditional methods. The knowledge opens a new dimension for introducing indica rice varieties to mountainous regions at higher altitudes and for selecting rice germplasm in these regions. In addition, the pattern of significant indica–japonica differentiation in rice varieties from Yunnan suggested the exotic origin of cultivated rice, which did not support the hypothesis that Yunnan is a part of the center of origin of rice, although it is certainly one of the centers of genetic diversity for rice. 相似文献
9.
Li-zhi Gao 《Genetic Resources and Crop Evolution》2003,50(1):17-32
As one of important original centers of Asian cultivated rice Oryza sativa L., China is abundant in genetic resources of rice and its wild relatives. They are not only useful for mountainous farmers to cope with heterogeneous microclimates, but also of extremely significance for rice genetic improvement programs in the future. Unfortunately, the combination of new conditions, including rapid population growth, new agricultural technology and swift economic & cultural changes produces a new environment. As a result, most of wild populations have disappeared, and others are at the edge of the extinction. Moreover, widespread adoption of high-yielding rice varieties (HYVs) have led to biological impoverty of rice germplasms, as local rice varieties are abandoned for modern varieties. These processes, known as genetic erosion, are generally summarized as two types in Chinese rice genetic resources. Based on our recent studies on the conservation of Chinese rice biodiversity, this paper reviews the biodiversity, ethnobotany and genetic erosion of rice and its wild relatives in China. Finally, some suggestions for the ways to enhance efforts to conserve rice genetic resources, including investigation of genetic erosion, studies on population genetics and conservation genetics using molecular approaches, settings of in situ & ex situ conservation priorities, significance of ethnobotanical knowledge for taking in situ conservation, and necessities of extensive participation in the conservation activities, are given. 相似文献
10.
A.P. Rodiño M. Santalla I. Montero P.A. Casquero A.M. De Ron 《Genetic Resources and Crop Evolution》2001,48(4):409-417
Common bean (Phaseolus vulgarisL.) is a traditional crop in Portugal, where farmers growvarieties selected and maintained by themselves. A collection of 88landraces of common bean was evaluated for 17 quantitative andqualitative traits and the biochemical marker phaseolin to displaythe degree of variation of this germplasm. Agronomic data weresubjected to cluster analysis and several groups were identified,with three groups clustering most of the landraces. Regardingphaseolin variation the C and T banding patterns are the mostfrequent ones, so the origin of the Portuguese beans is thus probablythe Andean region of South America. These results give informationabout the origin, diversity and breeding value of the Portuguesegermplasm, that could be useful to widen the genetic base ofcurrently cultivated bean varieties in Europe. 相似文献
11.
Temporal variation of diversity in Italian durum wheat germplasm 总被引：1，自引：0，他引：1
Giovanni Figliuolo Mariarosaria Mazzeo Ivana Greco 《Genetic Resources and Crop Evolution》2007,54(3):615-626
The aim of this work is to analyse the temporal change of genetic diversity in Italian durum wheat germplasm. The germplasm
deployed in this study (158 accessions), belonging to 5 different historical classes, was characterised for its microsatellite
and gliadin markers. The level of genetic diversity (He), based on gliadin and SSR markers results – on average – greater in indigenous landraces present in Italy before 1915, with
the exception of pure line material which had been selected from landraces (showing highest level of heterozigosity for gliadin
markers). Genotypes obtained from crosses or mutagenesis (referring to the 1950–1960 period) along with those resulting from
crosses between CIMMYT lines and old materials (1970s and beyond) were also genetically more diverse. Forty-nine percent of
indigenous landraces were genetically heterogeneous. Nine out of 53 landrace accessions were able to capture 4 different SSR
private alleles. It is speculated that the reduction of allele richness is an indicator of the genetic erosion of the pre-breeding
germplasm and it is pointed out that the implementation of appropriate methods of genetic conservation of this germplasm is
a priority for breeding and food safety. 相似文献
12.
Edurne Aguiriano Magdalena Ruiz Rosario Fité Jose M. Carrillo 《Genetic Resources and Crop Evolution》2006,53(8):1543-1552
In this work gliadin proteins were used to analyse the genetic variability in a sample of the durum wheat Spanish collection
conserved at the CRF-INIA. In total 38 different alleles were identified at the loci Gli-A1, Gli-A3, Gli-B5, Gli-B1, Gli-A2 and Gli-B2. All the gliadin loci were polymorphic, possessed large genetic diversity and small and large differentiation within and
between varieties, respectively. The Gli-A2 and Gli-B2 loci were the most polymorphic, the most fixed within varieties and the most useful to distinguish among varieties. Alternatively,
Gli-B1 locus presented the least genetic variability out of the four main loci Gli-A1, Gli-B1, Gli-A2 and Gli-B2. The Gli-B1 alleles coding for the gliadin γ-45, associated with good quality, had an accumulated frequency of 69.7%, showing that the
Spanish germplasm could be a good source for breeding quality. The Spanish landraces studied showed new gliadin alleles not
catalogued so far. These new alleles might be associated with specific Spanish environment factors. The large number of new
alleles identified also indicates that durum wheat Spanish germplasm is rather unique. 相似文献
13.
N. P. S. Dhillon R. Ranjana Kuldeep Singh I. Eduardo A. J. Monforte M. Pitrat N. K. Dhillon P. P. Singh 《Genetic Resources and Crop Evolution》2007,54(6):1267-1283
Diversity among 36 snapmelon landraces, collected from 2 agro-ecological regions of India (9 agro-climatic sub-regions), was
assayed using RAPD primers, morphological traits of plant habit and fruit, 2 yield-associated traits, pest and disease resistance
and biochemical composition (TSS, ascorbic acid, titrable acidity). Typical differences among accessions were observed in
plant and fruit characteristics and snapmelon germplasm with high titrable acidity and possessing resistance to downy mildew,
Cucumber mosaic virus, Zucchini yellow mosaic virus, Papaya ringspot virus, Aphis gossypii and Meloidogyne incognita was noticed in the collection. RAPD based grouping analysis revealed that Indian snapmelon was rich in genetic variation
and region and sub-region approach should be followed across India for acquisition of additional melon landraces. Accessions
of var. agrestis and var. momordica clustered together and there was a separate cluster of the accessions of var. reticulatus. Comparative analysis of the genetic variability among Indian snapmelons and an array of previously characterized reference
accessions of melon from Spain, Israel, Korea, Japan, Maldives, Iraq, Pakistan and India using SSRs showed that Indian snapmelon
germplasm contained a high degree of unique genetic variability which was needed to be preserved to broaden the genetic base
of melon germplasm available with the scientific community.
N. P. S. Dhillon and Ranjana contributed equally to this work and are considered the first authors. 相似文献
14.
Marc Moragues Jorge Zarco-Hernández Ma Angeles Moralejo Conxita Royo 《Genetic Resources and Crop Evolution》2006,53(5):993-1002
The genetic diversity of high and low molecular weight glutenin subunits of 63 durum wheat landraces from different geographical
regions in the Mediterranean Basin was studied using SDS-PAGE. Great variability in glutenin composition was found, with 42
high and low molecular weight glutenin haplotypes, 20 allele combinations at the HMW-GS loci, and 18 at the LMW-GS. All five possible LMW models were detected in all Mediterranean regions. Rare alleles were found at Glu-B1 locus in high frequencies and a priori related alleles to grain quality were also observed. Global genetic diversity index was relatively high (0.67); it ranged
from 0.33 to 0.66. Cluster analysis on the frequency patterns of origins grouped genotypes following a geographical structure.
Rogers’ distance coefficient on frequency pattern for each region of origin showed two germplasm pools with distinct quality
profiles, where South West Asian landraces were very different from the landraces of other Mediterranean areas. The relationship
between different regions of origin is discussed and two possible ways of introduction of wheat in the Iberian Peninsula (N
Africa and SE Europe) are hypothesized. The use of Mediterranean durum wheat landraces as source of genetic variability for
grain quality improvement is highly recommended. 相似文献
15.
Shuichi Fukuoka Tran Danh Suu Kaworu Ebana Luu Ngoc Trinh Tsukasa Nagamine Kazutoshi Okuno 《Genetic Resources and Crop Evolution》2006,53(4):753-761
Phenotypic variation of agronomic characters in aromatic rice (Oryza sativa L.) was analyzed in order to elucidate the genetic diversity of the populations of rice landraces. Thirteen populations in
Namdinh province, in the Red River Delta of Vietnam, were studied in both of farmers fields and an experimental field. Only
small differences were found in agronomic characters among the populations, including populations containing different varieties.
Variations among the populations in the frequency distributions of several characters suggested different degrees of diversity
among the populations even among populations with the same variety name. The phenotypic profiles of farmers fields were different
from those in an experimental field suggesting the environmental differences between them. One variety cultivated in the Myloc
district had different phenotypic characters from the other varieties in the Haihau district more clearly in the experimental
field. Since the small phenotypic variation in each of farm might be due to the genetic drift and selection by the farmers,
on farm conservation of the landraces of rice is considered to be under a force to decrease phenotypic diversity. The present
study suggests that the targeting several farms with different phenotypic profiles contribute to the conservation of regional
genetic diversity of the landraces of rice. 相似文献
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17.
L. Caballero R. J. Peña L. M. Martín J. B. Alvarez 《Genetic Resources and Crop Evolution》2010,57(5):657-665
One hundred lines derived from 14 wheat landraces collected in Mexico were characterized in relation to spike and grain morphology
and HMW-glutenin subunit composition. Up to seven botanical varieties were identified among these materials based in four
morphological traits. The remaining nine morphological traits showed wide variation. The allelic variation at the Glu-1 loci was wide, although showed a clear risk of genetic erosion due to the low frequency of some alleles. These genotypes
could be used as genetic resources to improve important biotic and abiotic traits as well as to widen genetic diversity controlling
the HMW glutenin subunit composition of common wheat. 相似文献
18.
Qiyi Lei Jiangju Zhou Wenhua Zhang Jing Luo Kainian Wu Chunlin Long 《Genetic Resources and Crop Evolution》2018,65(3):775-786
Panicle traits are the most intuitive and representative features of rice germplasm resources that have been utilized in the determination of its identity, genetic diversity, yield, and quality. Based on the approaches of ethnobotany, cultural anthropology and plant morphology, we analyzed the panicle traits of 95 traditional Kam fragrant glutinous rice landraces according to folk classification in Qiandongnan Prefecture of Guizhou Province in the past 10 years. A total of 95 Kam fragrant glutinous rice landraces were tested, of which 91% consisted of those with awns, and landraces with awn lengths of 2–6 cm comprised 62%. The coefficient of variation (CV) of awn color, husk color and Grain color was more than 50%, thereby indicating extensive morphological variations among the traditional Kam fragrant glutinous rice landraces. The average Shannon–Wiener value (diversity index, H′) for panicle qualitative traits was 0.50, which was significantly higher than that of quantitative traits (0.22), thereby indicating a relatively higher degree of genetic diversity among qualitative traits. Cluster analysis of panicle morphological traits showed that 95 Kam fragrant glutinous rice landraces could be divided into five categories, using the Euclidean distance of 0.68 as threshold. Each cultivar manifested unique panicle traits. The present study on the morphological diversity of Kam fragrant glutinous rice landraces provided basic information that may be utilized for the conservation and sustainable use of Kam fragrant glutinous rice landraces. 相似文献
19.
Ambiguity exists about the level of genetic diversity represented by farmer crop varieties, how it develops over time and
how it relates to the diversity comprised by formal varieties. As part of an interdisciplinary technological/sociological
study on farmer management of gene flow, upland rice (Oryza sativa L.) and late millet (Pennisetum glaucum (L.) R.Br.) from The Gambia were investigated for morphological and molecular variation. The goal of these analyses was to
obtain insight into the level of crop genetic diversity of farmer’s materials planted in several case study villages in The
Gambia. For both crops, samples were collected from villages and various research institutes. Based on variety names, different
rice and millet varieties were expected to be used in different villages. In fact, there was a large overlap in genetic diversity
for both crops, masked by the use of synonyms. The considerable similarity in rice genetic diversity between villages most
likely results from the exchange of varieties between farmers. For millet this seems the result of development of varieties
from the same gene pool. Some farmer varieties of rice, however, are apparent hybrid forms between the species O. sativa and O. glaberrima Steud., and farmer varieties in general displayed higher levels of genetic diversity than formal varieties. This indicates
that, for rice, genetic diversity develops in farmers’ fields and may have potential use in formal breeding programs. 相似文献
20.
Zeng Yawen Shen Shiquan Li Zichao Yang Zhongyi Wang Xiangkun Zhang Hongliang Wen Guosong 《Genetic Resources and Crop Evolution》2003,50(6):567-577
Yunnan is one of the largest centres of genetic ecological diversity and the richest area for elite germplasm of rice (O. sativa L.) resources in the world. Its indigenous rice average diversity index of six ecological groups are, in turn, javanica (1.2319) > aman (1.1738) > communis (1.1726) > nuda (1.1618) > aus (1.1371) > boro (0.9889), and there are great differences between indica (1.1454) and japonica (1.2081). The indigenous rice in Yunnan can be divided into 58 varieties, almost the total number found in China, and the cultivars account for 8.6% of the total cultivars in China. A great difference in ecological diversity index of rice resources between prefectures or counties in Yunnan province also exists, with the southwest part (Lincang, Xishuangbanna, Dehong, Simao) and southeast part (Wenshan) having been found to be the largest centre of genetic diversity, as their average genetic diversity index ranges from 1.2735 to 1.2036, especially. The average diversity index of the Cangyuan, Gengma, Zhenkang, Yongde, Yingjiang, Jinghong, Menghai, Shuangjiang, Ruili, Longchuan, Mojiang, Wenshan and Guangnan counties, in particular, have an average diversity index ranging from 0.8 to1.0. On the contrary, in Diqing, Dongchuan, Kunming, Lijiang, Qujing, Chuxiong, it is comparatively low, i.e., 0.7843–1.1075. Differences in the ecological diversity index of rice resources between rice regions are small, only 1.1322 to 1.2849. 相似文献