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1.
Molecular markers in Brassica oilseed breeding: current status and future possibilities 总被引：6，自引：0，他引：6
As PCR techniques have developed over the last 15 years, a wealth of new DNA marker technologies have arisen which have enabled the generation of high‐density molecular maps for all the major Brassica crop species. Molecular markers have also been heavily used in analyses of genetic diversity in Brassica crops. The majority of the work utilizing molecular markers in Brassica oilseed breeding has to date been based on genetic mapping using various DNA marker systems in segregating populations generated for specific investigations of particular traits of interest. For numerous qualitative traits, traditional mapping approaches have led to the development of marker‐assisted selection strategies in oilseed Brassica breeding, and in some cases to map‐based cloning of the responsible genes. For quantitative traits, however, it has become apparent that traditional mapping of quantitative trait loci (QTL) is often not sufficient to develop effective markers for trait introgression or for identification of the genes responsible. In this case, allele‐trait association studies in non‐structured genetic populations represent an interesting new approach, provided the degree of gametic phase disequilibrium between the QTL and the marker loci is sufficient. Because Brassica species represent the closest crop plant relatives to the model plant Arabidopsis thaliana, significant progress will be achieved in the coming years through integration of candidate gene approaches in crop brassicas, using the detailed information now available for the Arabidopsis genome. Integration of information from the model plant with the increasing supply of data from physical mapping and sequencing of the diploid Brassica genomes will undoubtedly give great insight into the genetics underlying both simple and complex traits in oilseed rape. This review describes the current use of available genetic marker technologies in oilseed rape breeding and provides an outlook for use of new technologies, including single‐nucleotide polymorphism markers, candidate gene approaches and allele‐trait association studies. 相似文献
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Dorota Soltys-Kalina Jaros?aw Plich Danuta Strzelczyk-?yta Jadwiga ?liwka Waldemar Marczewski 《Breeding Science》2016,66(2):328-331
Drought tolerance in plants is a complex trait involving morphological, physiological, and biochemical mechanisms. Hundreds of genes underlie the response of plants to the stress. For crops, selecting cultivars that can produce economically significant yields under drought is a priority. Potato (Solanum tuberosum L.) is considered as drought sensitive crop, although cultivar-dependent differences in tolerance have been described. Cultivar ‘Katahdin’ possesses many appropriate characteristics and is widely used for breeding purposes worldwide; it also has enhanced tolerance to drought stress. In this study, we evaluated cv. ‘Katahdin’ and a half-sib family of 17 Katahdin-derived cultivars for leaf relative water content (RWC) and tuber yield under drought stress. The yields of cultivars ‘Wauseon’, ‘Katahdin’, ‘Magura’, ‘Calrose’, and ‘Cayuga’ did not significantly decline under drought stress. Among these five, Wauseon exhibited the lowest reduction in both tuber yield and relative water content under water shortage. The data showed that ‘Wauseon’ is the most attractive cultivar for studies of molecular and physiological processes under drought and for potato breeding due to low yield losses that correspond with high RWC values. This cultivar can serve as a reservoir of potentially useful genes to develop cultivars with enhanced tolerance to this abiotic stress. 相似文献
5.
Drought and salt tolerances are complex traits and controlled by multiple genes, environmental factors and their interactions. Drought and salt stresses can result in more than 50% yield loss in Upland cotton (Gossypium hirsutum L.). G. barbadense L. (the source of Pima cotton) carries desirable traits such as tolerance to abiotic and biotic stress along with high fiber quality. However, few studies have been reported on mapping quantitative trait loci (QTL) for abiotic stress tolerance using a permanent bi-parental population in multiple tests. The transfer of drought and salt tolerance from Pima to Upland cotton has been a challenge due to interspecific hybrid breakdown. This issue may be overcome by using introgression lines with genes transferred from Pima to Upland cotton. In this study, four replicated tests were conducted in the greenhouse each for drought and salt tolerance along with another test conducted in a field for drought tolerance using an Upland recombinant inbred line population of TM-1/NM24016 that has a stable introgression from Pima cotton. The objectives of the study were to investigate the genetic basis of drought and salt tolerance and to identify genetic markers associated with the abiotic stress tolerance. A total of 1004 polymorphic DNA marker loci including RGA-AFLP, SSR and GBS-SNP markers were used to construct a genetic map spanning 2221.28 cM. This population together with its two parents was evaluated for morphological, physiological, yield and fiber quality traits. The results showed that drought under greenhouse and field conditions and salt stress in the greenhouse reduced cotton plant growth at the seedling stage, and decreased lint yield and fiber quality traits in the field. A total of 165 QTL for salt and drought tolerance were detected on most of the cotton chromosomes, each explaining 5.98–21.43% of the phenotypic variation. Among these, common QTL for salt and drought tolerance were detected under both the greenhouse and field conditions. This study represents the first study to report consistent abiotic stress tolerance QTL from multiple tests in the greenhouse and the field that will be useful to understand the genetic basis of drought and salt tolerance and to breeding for abiotic stress tolerance using molecular marker-assisted selection in cotton. 相似文献
6.
E. M. Agbicodo C. A. Fatokun S. Muranaka R. G. F. Visser C. G. Linden van der 《Euphytica》2009,167(3):353-370
This review presents an overview of accomplishments on different aspects of cowpea breeding for drought tolerance. Furthermore
it provides options to enhance the genetic potential of the crop by minimizing yield loss due to drought stress. Recent efforts
have focused on the genetic dissection of drought tolerance through identification of markers defining quantitative trait
loci (QTL) with effects on specific traits related to drought tolerance. Others have studied the relationship of the drought
response and yield components, morphological traits and physiological parameters. To our knowledge, QTLs with effects on drought
tolerance have not yet been identified in cowpea. The main reason is that very few researchers are working on drought tolerance
in cowpea. Some other reasons might be related to the complex nature of the drought stress response, and partly to the difficulties
associated with reliable and reproducible measurements of a single trait linked to specific molecular markers to be used for
marker assisted breeding. Despite the fact that extensive research has been conducted on the screening aspects for drought
tolerance in cowpea only very few—like the ‘wooden box’ technique—have been successfully used to select parental genotypes
exhibiting different mechanisms of drought tolerance. Field and pot testing of these genotypes demonstrated a close correspondence
between drought tolerance at seedling and reproductive stages. Some researchers selected a variety of candidate genes and
used differential screening methods to identify cDNAs from genes that may underlie different drought tolerance pathways in
cowpea. Reverse genetic analysis still needs to be done to confirm the functions of these genes in cowpea. Understanding the
genetics of drought tolerance and identification of DNA markers linked to QTLs, with a clear path towards localizing chromosomal
regions or candidate genes involved in drought tolerance will help cowpea breeders to develop improved varieties that combine
drought tolerance with other desired traits using marker assisted selection.
相似文献
7.
Tianxiao Chen Yajun Zhu Kai Chen Congcong Shen Xiuqin Zhao Sergey Shabala Lana Shabala Holger Meinke Gayatri Venkataraman Zhong-Hua Chen Jianglong Xu Meixue Zhou 《Journal of Agronomy and Crop Science》2020,206(2):202-213
Salt stress is an ever-present threat to rice production worldwide. Rice salinity tolerance is complex, both genetically and physiologically. The success and effectiveness in selecting salt-tolerant rice variety require the identification of QTL for the tolerance and closely linked molecular markers. In the present study, a RIL population consisting of 148 lines, derived from a cross between IR29 (salt-sensitive) and Pokkali (salt-tolerant), was used to identify new QTL for salt tolerance and investigate the relationships between salt stress caused injury and the changes in different physiological and morphological traits at the seedling stage. 14,470 high-quality SNP markers generated by the Rice 56K SNP array were converted to 1,467 bin markers for linkage mapping. A high-density genetic linkage map covering 1,680.9 cM was constructed, with the physical to genetic distance ratio being 222 Kb/cM. In total, 23 QTL for different salt tolerance indices were identified, including the previously reported Saltol which is currently used in breeding programmes. Three QTL for salt injury score (SIS) were located on chromosomes 1, 4 and 12, all being closely related to the long-distant Na+ transport from roots to shoots. These QTL showed additive effects, thus can be effectively used in breeding programme to pyramid various tolerance genes. 相似文献
8.
Tissue culture-derived variation in crop improvement 总被引：30，自引：3，他引：30
S. Mohan Jain 《Euphytica》2001,118(2):153-166
Tissue culture generates a wide range of genetic variation in plant species which can be incorporated in plant breeding programmes.
By in vitro selection, mutants with useful agronomic traits, e.g. salt or drought tolerance or disease resistance, can be isolated in
a short duration. The successful use of somaclonal variation is very much dependent on its genetic stability in the subsequent
generations for which molecular markers such as RAPDs, AFLPs, SSRs and others can be helpful. The potential of somaclonal
variation has yet to be fully exploited by breeders, even though a few cultivars have been developed in crops such as Brassica juncea, rice and others.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Brassicaceae crops display strong hybrid vigor, and have long been subject to F1 hybrid breeding. Because the most reliable system of F1 seed production is based on cytoplasmic male sterility (CMS), various types of CMS have been developed and adopted in practice to breed Brassicaceae oil seed and vegetable crops. CMS is a maternally inherited trait encoded in the mitochondrial genome, and the male sterile phenotype arises as a result of interaction of a mitochondrial CMS gene and a nuclear fertility restoring (Rf) gene. Therefore, CMS has been intensively investigated for gaining basic insights into molecular aspects of nuclear-mitochondrial genome interactions and for practical applications in plant breeding. Several CMS genes have been identified by molecular genetic studies, including Ogura CMS from Japanese radish, which is the most extensively studied and most widely used. In this review, we discuss Ogura CMS, and other CMS systems, and the causal mitochondrial genes for CMS. Studies on nuclear Rf genes and the cytoplasmic effects of alien cytoplasm on general crop performance are also reviewed. Finally, some of the unresolved questions about CMS are highlighted. 相似文献
10.
Hao Wang Liyan Liang Shuo Liu Tingting An Yan Fang Bingcheng Xu Suiqi Zhang Xiping Deng Jairo A. Palta Kadambot H. M. Siddique Yinglong Chen 《Journal of Agronomy and Crop Science》2020,206(6):711-721
Maize (Zea mays L.) is susceptible to salinity but shows genotypic variation for salt tolerance. How maize genotypes with contrasting root morphological traits respond to salt stress remains unclear. This study assessed genotypic variation in salinity tolerance of 20 maize genotypes with contrasting root systems exposed to NaCl for 10 days (0, 50 mM or 100 mM NaCl, added in four increments every other day from 14 days after transplanting, DAT) in a semi-hydroponic phenotyping system in a temperature-controlled greenhouse. Considerable variation was observed for each of the 12 measured shoot and root traits among the 20 genotypes under NaCl treatments. Salt stress significantly decreased biomass production by up to 54% in shoots and 37% in roots compared with the non-saline control. The 20 genotypes were classified as salt-tolerant (8 genotypes), moderately tolerant (5) and salt-sensitive (7) genotypes based on the mean shoot dry weight ratio (the ratio of shoot dry weight at 100 mM NaCl and non-saline control) ± one standard error. The more salt-tolerant genotypes (such as Jindan52) had less reductions in growth, and lower shoot Na+ contents and higher shoot K+/Na+ ratios under salt stress. The declared salt tolerance was positively correlated with shoot height, shoot dry weight and primary root depth, and negatively correlated with shoot Na+ content at 100 mM NaCl. Primary root depth is critical for identifying salt responsiveness in maize plants and could be suggested as a selection criterion for screening salt tolerance of maize during early growth. The selected salt-tolerant genotypes have potentials for cultivation in saline soils and for developing high-yielding salt-tolerant maize hybrids in future breeding programmes. 相似文献
11.
Heping Wan Yinke Wei Jiali Qian Yunlei Gao Jing Wen Bin Yi Chaozhi Ma Jinxing Tu Tingdong Fu Jinxiong Shen 《Euphytica》2018,214(10):190
Soil salinization has a major effect on crop yield. Seed germination is a crucial prerequisite for the successful cultivation of rapeseed in saline soils. Limited information is available about rapeseed salt tolerance at germination stage. Here, we carried out an association mapping of salt tolerance QTLs at seed germination stage. We evaluated salt tolerance of 214 rapeseed inbred lines at germination stage, and the 60 K Brassica Infinium® SNP array was used to genotype the association panel. Finally, a total of 110 single nucleotide polymorphisms (SNPs) were associated with three salt tolerance indices and these SNPs were integrated into 44 QTLs. In addition, 56 possible candidate genes were located in or near the genomic region where the above QTLs were mapped. Thus, our results provide valuable information for understanding the genetic control of rapeseed salt tolerance at germination stage and may facilitate marker-based breeding for rapeseed salt tolerance. 相似文献
12.
Genetic analysis of salt tolerance during vegetative growth in tomato, Lycopersicon esculentum Mill. 总被引：1，自引：0，他引：1
M. R. Foolad 《Plant Breeding》1996,115(4):245-250
Breeding for salt tolerance in tomato has been impeded by insufficient knowledge of the genetic control of tolerance. The genetic basis of salt tolerance during vegetative growth was investigated by growing a salt-tolerant (PI174263) and a salt-sensitive tomato cultivar (UCT5) and their F1, F2 and backcross progeny in saline solutions with electrical conductivity of 0.5 (control) and 20 dS/m (salt-stress). The relative salt-tolerance of each generation was determined as the percentage of growth (i.e. dry matter production) under salt-stress relative to growth under control conditions. In all generations, shoot growth was significantly reduced by salt stress. The reduction was largest in UCT5 (56.1%) and smallest in the F1 (27.4%), followed by PI174263 (32.3%). Analysis of the absolute and relative growth under salt-stress indicated that genes contributing to vigour might be different from genes conferring tolerance. Generation means analyses of the absolute and relative growth indicated that the majority of the genetic variation among generations were due to simple (additive and dominance) genetic effects; nonallelic interactions, although significant, were far less important. Partitioning of the total genetic variance by weighted least-square regression analysis and variance component analysis indicated that 88% or more of the variation was due to additive genetic effects. A moderate estimate of narrow sense heritability (0.49 ± 0.09) was obtained for shoot DW under salt-stress treatment. The results indicate that tomato salt-tolerance during vegetative growth can be improved by breeding and selection. 相似文献
13.
Estimation of salt tolerance in Andrographis paniculata accessions using multiple regression model 总被引：1，自引：0，他引：1
The complexity and polygenic nature of the salt tolerance trait in plants needs to develop a multiple indicator in the screening process. The mentioned issue led us to carry out an experiment to identify tolerant genotypes through multiple parameters in Andrographis paniculata. For this purpose, the 40-days seedlings were grown in different salinity levels (control, 4, 8, 12 and 16?dS?m?1) on Hoagland??s medium. The results indicated that salinity had a significant effect on the morphological, physiological and biochemical traits. All measured morphological traits, and chlorophyll, K+ and Ca2+ content were significantly decreased with increasing salinity levels, while proline and Na+ content increased. The present exploration revealed that, salt tolerance index (STI), using the multiple regression model, demonstrated a more stable trend than the single variable assay (total dry weight). Furthermore, STI based on multiple regression analysis gives an accurate definition of salt-tolerant individuals. Under salt stress, tolerant accessions had high STI and produced higher proline, K+ and Ca2+, and lower Na+ content than sensitive accessions. Cluster analysis based on related traits to STI, indicated high similarity in each group. These outcomes can be utilized to evaluate the salt tolerance threshold in the species and may have a great advantage over conventional methods. Probably, our upshots can be applied in the next breeding programs to develop salt-tolerant varieties. 相似文献
14.
Masahiko Ishida Masakazu Hara Nobuko Fukino Tomohiro Kakizaki Yasujiro Morimitsu 《Breeding Science》2014,64(1):48-59
Unique secondary metabolites, glucosinolates (S-glucopyranosyl thiohydroximates), are naturally occurring S-linked glucosides found mainly in Brassicaceae plants. They are enzymatically hydrolyzed to produce sulfate ions, D-glucose, and characteristic degradation products such as isothiocyanates. The functions of glucosinolates in the plants remain unclear, but isothiocyanates possessing a pungent or irritating taste and odor might be associated with plant defense from microbes. Isothiocyanates have been studied extensively in experimental in vitro and in vivo carcinogenesis models for their cancer chemopreventive properties. The beneficial isothiocyanates, glucosinolates that are functional for supporting human health, have received attention from many scientists studying plant breeding, plant physiology, plant genetics, and food functionality. This review presents a summary of recent topics related with glucosinolates in the Brassica family, along with a summary of the chemicals, metabolism, and genes of glucosinolates in Brassicaceae. The bioavailabilities of isothiocyanates from certain functional glucosinolates and the importance of breeding will be described with emphasis on glucosinolates. 相似文献
15.
Grain legumes being affordable sources of proteins, vitamins and essential micronutrients are key to human nutrition worldwide. However, frequent drought episodes present serious threat to grain legume production worldwide. Advances in legume omics in concert with evolving phenotyping and breeding techniques hold great promise to improve drought response of these crops. These resources could underpin prebreeding efforts to expedite discovery and deployment of novel drought tolerance traits into elite backgrounds. Fast-track transfer of traits that confer drought tolerance using marker technologies has been demonstrated in grain legumes like chickpea. However, complex genetic architecture of drought tolerance demands embracing more efficient tools like genomic selection (GS) for accelerated trait improvement. Recent studies on GS for addressing complex traits like drought tolerance have yielded encouraging results in these crops. Recently, speed breeding (SB) protocols have also been optimized for the improvement of long-day/day-neutral grain legumes. Efficacy of SB protocols with regard to complex traits awaits further evidences though. There remains immense scope for integrating SB with GS and gene editing to deliver drought-tolerant cultivars. 相似文献
16.
Yasir Serag Alnor Mohammed Amin Elsadig Eltayeb Hisashi Tsujimoto 《Breeding Science》2013,63(4):407-416
Aluminum (Al) toxicity is the key factor limiting wheat production in acid soils. Soil liming has been used widely to increase the soil pH, but due to its high cost, breeding tolerant cultivars is more cost-effective mean to mitigate the problem. Tolerant cultivars could be developed by traditional breeding, genetic transformation or introgression of genes from wild relatives. We used 30 wheat alien chromosome addition lines to identify new genetic resources to improve wheat tolerance to Al and to identify the chromosomes harboring the tolerance genes. We evaluated these lines and their wheat background Chinese Spring for Al tolerance in hydroponic culture at various Al concentrations. We also investigated Al uptake, oxidative stress and cell membrane integrity. The L. racemosus chromosomes A and E significantly enhanced the Al tolerance of the wheat in term of relative root growth. At the highest Al concentration tested (200 μM), line E had the greatest tolerance. The introgressed chromosomes did not affect Al uptake of the tolerant lines. We attribute the improved tolerance conferred by chromosome E to improved cell membrane integrity. Chromosome engineering with these two lines could produce Al-tolerant wheat cultivars. 相似文献
17.
Linghe Zeng James A. Poss Clyde Wilson Abdel-Salam E. Draz Glenn B. Gregorio Catherine M. Grieve 《Euphytica》2003,129(3):281-292
The use of physiological characters as selection criteria in salt tolerance breeding requires the identification of the contribution
each individual character makes to salt tolerance. Rice genotypes were evaluated for salt tolerance in terms of grain yield
and physiological characters. Plants of twelve genotypes were grown in sand tanks in a greenhouse and irrigated with Yoshida
nutrient solution. Sodium chloride and calcium chloride (5:1 molar ratio) were added at two concentrations to give moderate
(4.5 dS m-1) and high (8.3 dS m-1) salinity treatments. One set of plants was harvested at 635 °Cċd (accumulative thermal time) after planting to determine LAI and mineral ion concentrations. Another set of plants was
allowed to grow to maturity. High genotypic diversity for LAI and shoot ion contents was observed. LAI contributed the most
to the variation of the grain yield under salt stress. Significant
correlations between LAI and yield components in both salt-tolerant and-sensitive genotypes further confirmed the significant
contribution of LAI to grain yield. K-Na selectivity increased with increasing salinity. Conversely, Na-Ca selectivity decreased
with increasing salinity. Significant correlations were identified between grain yield and both Na-Ca and K-Na selectivity.
Highly significant (p<0.001) correlations were identified between Na-Ca selectivity and the rankings among genotypes for grain yield. Thus, Na-Ca
selectivity could be one salt tolerance component and an useful selection criterion in screening for salt tolerance.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
Absence of a genetic relationship between salt tolerance during seed germination and vegetative growth in tomato 总被引：10，自引：0，他引：10
Two approaches were used to determine the relationship between salt tolerance during seed germination and vegetative growth in tomato. First, F4 progeny families of a cross between a breeding line, ‘UCT5’ (salt sensitive at all developmental stages), and a primitive cultivar, ‘PI 174263’ (salt tolerant during germination and vegetative growth), were evaluated in separate experiments for salt tolerance during germination and vegetative growth. There were significant differences among the F4 families in both the rate of seed germination and the plant growth (dry matter production) under salt stress. There was, however, no significant correlation between the ability of seeds to germinate rapidly and the ability of plants to grow under salt stress. In the second approach, selection was made for rapid germination under salt stress in an F2 population of the same cross and the selected progeny was evaluated for salt tolerance during both germination and vegetative growth. The results indicated that selection for salt tolerance during germination significantly improved germination performance under salt stress; a realized heritability estimate of 0.73 was obtained. Selection for salt tolerance during germination, however, did not affect plant salt tolerance during vegetative growth; there was no significant difference between the selected and unselected progeny based on either absolute or relative growth under salt stress. Obviously, in these genetic materials, salt tolerance during germination and vegetative growth are controlled by different mechanisms. Thus, to develop tomato cultivars with improved salt tolerance, selection protocols that include all critical developmental stages would be desirable. 相似文献
19.
Analysis of Water Supply of Plants Under Saline Soil Conditions and Conclusions for Research on Crop Salt Tolerance 总被引：1，自引：1，他引：0
U. Schleiff 《Journal of Agronomy and Crop Science》2008,194(1):1-8
Abstract In the dry areas of the world there is an increasing pressure to apply low quality brackish waters for plant irrigation (agriculture, horticulture, landscape greening). Consequently there is a demand to improve salt tolerance of conventional crops and to develop adequate irrigation techniques too. The efforts in the past decades to approach the understanding of salt stress mechanism by focusing on biochemical and physiological research were disappointing with respect to progress for crop growth and yields under saline soil conditions. However, it is generally agreed by all disciplines involved in research for crop salt tolerance that under saline soils conditions the reduced water supply of crops is the most critical growth factor. The paper presents some model calculations and field investigations that demonstrate the effect of root water uptake on the salinity of the root surrounding soil fraction (rhizospheric soil). It is shown that root hair length and rhizospheric soil volumes are factors most relevant for understanding crop salt tolerance, when growing in soils. It is postulated that short root hairs contribute to a lower salt tolerance (onions), whereas long root hairs enhance water uptake from saline soils and crop salt tolerance (rape). As interactions between roots and soil contribute to the salt tolerance of crops under field conditions, it is doubtful that selection for salt tolerant varieties and breeding for salt tolerance under conditions of water and flow culture experiments is very efficient. Breeding for more salt-tolerant crops and brackish irrigation techniques should consider root morphology and soil/root contact zone. 相似文献