Molecular diversity and genetic structure of modern and traditional landrace cultivars of wheat (Triticum aestivum L.)

2010 ◽  
Vol 61 (3) ◽  
pp. 222 ◽  
Author(s):  
Harsh Raman ◽  
B. J. Stodart ◽  
Colin Cavanagh ◽  
M. Mackay ◽  
Matthew Morell ◽  
...  

Wheat is one of the most important cereal crops of the world. In order to achieve continued genetic gain in wheat improvement programs, an assessment and utilisation of genetic diversity in a wide range of germplasm are required. The Australian Winter Cereal Collection (AWCC, Tamworth) holds over 33 000 accessions of wheat. In this study, we scanned the genome of 1057 accessions of hexaploid common wheat (Triticum aestivum L.) originating from different geographic regions of the world, with 178 polymorphic DArT™ markers. These accessions comprised modern cultivars (MCs), advanced breeding lines (BLs), and landrace cultivars (LCs). Our results indicate that the LCs had higher polymorphic information content (PIC values) than the MCs and BLs. Cluster and principal coordinate analysis based on genetic distance matrices enabled classification of the 1057 accessions into 12 subgroups. The structure of subgroups appeared to be geographically determined and was generally consistent with pedigrees. Molecular analyses revealed that LCs have unique alleles compared with MCs and BLs, which may be useful for the genetic improvement of wheat.

Author(s):  
Ali Hussain Al Lawati ◽  
Saleem Kaseemsaheb Nadaf ◽  
Nadiya Abubakar Al Saady ◽  
Saleh Ali Al Hinai ◽  
Almandhar Almamari ◽  
...  

Oman is endowed with enormous diversity of important food crops that have global significance for food security and has ancient history of cultivation of bread wheat (Triticum aestivum L.) with its divergent landraces, which are useful in crop improvement. 55 indigenous Omani accessions conserved at the USDA were evaluated in the winter season (November to April) of the years 2017-2018 and 2018-2019 on loamy soil under sprinklers in augmented design with 5 check varieties in 5 replications following crop husbandry practices as per national recommendations using 9 quantitative (descriptors) and 6 qualitative traits (anthocyanin pigmentation on plant parts). The data on traits were subjected not only for PC values and D values after varimax rotation through Kaiser normalization in Principal Component Analysis (PCA) but also for Agglomerative Hierarchical Clustering (AHC). The results indicated that indigenous bread wheat accessions were significantly different (p>0.05) for all the quantitative traits except number of tillers. The multivariate analyses led to formation of four diverse clusters from PCA analyses corresponding to four quadrants of bi-plot graphs and three clusters from AHC analysis corresponding to main clades of dendrogram. The parents were selected from common accessions of distinct clusters in all the multivariate analyses for hybridization for improving characters of growth for higher yield or productivity with pigmentation on one or two plant parts useful for DUS test of varieties. The indigenous bread wheat landraces / accessions were genetically diverse and have potential for use in national crop improvement programs for earliness and higher grain productivity with distinct identification markers.


2008 ◽  
Vol 88 (5) ◽  
pp. 997-1013 ◽  
Author(s):  
C. J. Willenborg ◽  
R. C. Van Acker

This review summarizes the biological and ecological factors of hexaploid wheat (Triticum aestivum L.) that contribute to trait movement including the ability to volunteer, germination and establishment characteristics, breeding system, pollen movement, and hybridization potential. Although wheat has a short-lived seedbank with a wide range of temperature and moisture requirements for germination and no evidence of secondary dormancy, volunteer wheat populations are increasing in relative abundance and some level of seed persistence in the soil has been observed. Hexaploid wheat is predominantly self-pollinating with cleistogamous flowers and pollen viability under optimal conditions of only 0.5 h, yet observations indicate that pollen-mediated gene flow can and will occur at distances up to 3 km and is highly dependent on prevailing wind patterns. Hybridization with wild relatives such as A. cylindrica Host., Secale cereale L., and Triticum turgidum L. is a serious concern in regions where these species grow in field margins and unmanaged lands, regardless of which genome the transgene is located on. More research is needed to determine the long-term population dynamics of volunteer wheat populations before conclusions can be drawn with regard to their role in trait movement. Seed movement has the potential to create adventitious presence (AP) on a larger scale than pollen, and studies tracing the movement of wheat seed in the grain handling system are needed. Finally, the development of mechanistic models that predict landscape-level trait movement are required to identify transgene escape routes and critical points for gene containment in various cropping systems. Key words: Triticum, coexistence, gene flow, genetically-engineered, herbicide-resistant, trait confinement


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Pavel Feduraev ◽  
Liubov Skrypnik ◽  
Anastasiia Riabova ◽  
Artem Pungin ◽  
Elina Tokupova ◽  
...  

Reacting to environmental exposure, most higher plants activate secondary metabolic pathways, such as the metabolism of phenylpropanoids. This pathway results in the formation of lignin, one of the most important polymers of the plant cell, as well as a wide range of phenolic secondary metabolites. Aromatic amino acids, such as phenylalanine and tyrosine, largely stimulate this process, determining two ways of lignification in plant tissues, varying in their efficiency. The current study analyzed the effect of phenylalanine and tyrosine, involved in plant metabolism through the phenylalanine ammonia-lyase (PAL) pathway, on the synthesis and accumulation of phenolic compounds, as well as lignin by means of the expression of a number of genes responsible for its biosynthesis, based on the example of common wheat (Triticum aestivum L.).


Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1075
Author(s):  
Mateusz Przyborowski ◽  
Sebastian Gasparis ◽  
Maciej Kała ◽  
Wacław Orczyk ◽  
Anna Nadolska-Orczyk

Wheat (Triticum aestivum L.) grain hardness is determined mainly by variations in puroindoline genes (Pina-D1 and Pinb-D1), which are located on the short arm of chromosome 5D. This trait has a direct effect on the technological properties of the flour and the final product quality. The objective of the study was to analyze the mutation frequency in both Pin genes and their influence on grain hardness in 118 modern bread wheat cultivars and breeding lines cultivated in Poland, and 80 landraces from Poland. The PCR products containing the Pin gene coding sequences were sequenced by the Sanger method. Based on detected the SNPs (single-nucleotide polymorphisms) we designed CAPS (cleaved amplified polymorphic sequence) markers for the fast screening of Pinb alleles in a large number of genotypes. All analyzed cultivars, breeding lines, and landraces possess the wild-type Pina-D1a allele. Allelic variation was observed within the Pinb gene. The most frequently occurring allele in modern wheat cultivars and breeding lines (over 50%) was Pinb-D1b. The contribution of the remaining alleles (Pinb-D1a, Pinb-D1c, and Pinb-D1d) was much less (approx. 15% each). In landraces, the most frequent allele was Pinb-D1a (over 70%), followed by Pinb-D1b (21% frequency). Pinb-D1c and Pinb-D1g were found in individual varieties. SKCS (single-kernel characterization system) analysis revealed that grain hardness was strictly connected with Pinb gene allelic variation in most tested cultivars. The mean grain hardness values were significantly greater in cultivars with mutant Pinb variants as compared to those with the wild-type Pinb-D1a allele. Based on grain hardness measured by SKCS, we classified the analyzed cultivars and lines into different classes according to a previously proposed classification system.


2019 ◽  
Vol 72 ◽  
pp. 02005
Author(s):  
Maret Betilmerzaeva

At the intersection of various trends, the displacement of cultures and ideologies in modern Chechen society, there is a wide range of social polymorphism when individuals who practically represent one ethnic culture, depending on the social environment, acquire various phenotypic forms due to the interaction of the genotype with the environment. A classification of cultural trends is proposed, within the framework of which the worldview of the modern young Chechen in the Republic is being formed. The simultaneous coexistence of such different trends with the active interaction of their actors introduces transgressive changes in the consciousness of that part of young people with a problematic level of psychological and social adaptability to a changing world. The conducted analysis shows that in the process of forming the worldview of a modern young person a consciousness must be developed that adequately reflects objective reality in a subjective picture of the world based on healthy social interaction.


2012 ◽  
Vol 37 (3) ◽  
pp. 389-398 ◽  
Author(s):  
S Islam ◽  
MS Haque ◽  
RM Emon ◽  
MM Islam ◽  
SN Begum

A study was undertaken to examine the genetic diversity of 12 wheat (Triticum aestivum L.) genotypes, using 4 simple sequence repeats (SSRs). A total of 10 alleles were found. Allele number per locus ranged from 2 to 4 with an average of 2.5. The polymorphic information content (PIC) values ranged from 0.2755 to 0.5411 with an average of 0.3839. The average gene diversity over all SSR loci for the 12 wheat genotypes was 0.4688, ranging from 0.3299 to 0.6042. Cluster analysis based on microsatellite allelic diversity discriminated the varieties into different clusters. Genetic diversity was the highest between variety Gourab and Akbar as well as Gourab and BAW-1064, showing a genetic distance value of 0.4697. The genetic distance was lowest between Balaka and Aghrani as well as Triticale and BAW-1036. Positive correlations were found between gene diversity, number of alleles, the allele size range and the types of repeat motif of microsatellite markers. It was found from this study that microsatellite markers could characterize and discriminate all of the genotypes. More primers should be used for saturation of different regions in further studies. Bangladesh J. Agril. Res. 37(3): 389-398, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12082


Genome ◽  
2011 ◽  
Vol 54 (10) ◽  
pp. 836-844 ◽  
Author(s):  
Cheng Liu ◽  
Lili Qi ◽  
Wenxuan Liu ◽  
Wanchun Zhao ◽  
Jamie Wilson ◽  
...  

Dasypyrum villosum (L.) Candargy, a wild relative of bread wheat ( Triticum aestivum L.), is the source of many agronomically important genes for wheat improvement. Production of compensating Robertsonian translocations (cRobTs), consisting of D. villosum chromosome arms translocated to homoeologous wheat chromosome arms, is one of the initial steps in exploiting this variation. The cRobTs for D. villosum chromosomes 1V, 4V, and 6V have been reported previously. Here we report attempted cRobTs for wheat – D. villosum chromosome combinations 2D/2V, 3D/3V, 5D/5V, and 7D/7V. The cRobTs for all D. villosum chromosomes were recovered except for the 2VS and 5VL arms. As was the case with the 6D/6V combination, no cRobTs involving 2D/2V chromosomes were recovered; instead, cRobT T2BS·2VL involving a nontargeted chromosome was recovered. All cRobTs are fertile, although the level of spike fertility and hundred kernel weight (HKW) varied among the lines. The set of cRobTs involving 12 of the 14 D. villosum chromosomes will be useful in wheat improvement programs. In fact, among the already reported cRobTs, T6AL·6VS carrying the Pm21 gene is deployed in agriculture and many useful genes have been reported on other cRobTs including resistance to stem rust race UG99 on T6AS·6VL.


2019 ◽  
Author(s):  
Jiali Ye ◽  
Xuetong Yang ◽  
Zhiquan Yang ◽  
Wei Li ◽  
Qi Liu ◽  
...  

Abstract Background: Polygalacturonase (PG) belongs to a large family of hydrolases with important functions in cell separation during plant growth and development via the degradation of pectin. The specific expression of PG genes in anthers may be significant for male sterility research and hybrid wheat breeding, but it has not been characterized in wheat (Triticum aestivum L.). Results: We systematically studied the PG gene family using the latest published wheat reference genomic information. In total, 113 wheat PG genes were identified and renamed as TaPG01–113 based on their chromosomal positions. The PG genes are unequally distributed on 21 chromosomes and classified according to six categories from A–F. Analysis of the gene structures and conserved motifs demonstrated that the Class C and D TaPGs have relatively short gene sequences and a small number of introns. Class E TaPGs are the least conserved and lack conserved domain III. Polyploidy and segmental duplications in wheat were mainly responsible for the expansion of the wheat PG gene family. Predictions of cis-elements indicate that TaPGs have a wide range of functions, including the responses to light, hypothermia, anaerobic conditions, and hormonal stimulation, as well as being involved in meristematic tissue expression. RNA-seq showed that TaPGs have specific temporal and spatial expression characteristics. Twelve spike-specific TaPGs were screened using RNA-seq data and verified by qRT-PCR in the sterile and fertile anthers of thermo-sensitive male-sterile wheat. Four important candidate genes were identified as involved in the male fertility determination process. In fertile anthers, TaPG09 may be involved in the separation of pollen. TaPG87 and TaPG95 could play important roles in anther dehiscence. TaPG93 may be related to pollen development and pollen tube elongation. Conclusions: We analyzed the wheat PG gene family and identified four important TaPGs with differential expression levels in the wheat fertility conversion process. Our findings may facilitate functional investigations of the wheat PG gene family and provide new insights into the fertility conversion mechanism in male-sterile wheat.


2018 ◽  
Vol 23 ◽  
pp. 143-147
Author(s):  
V. M. Tishchenko ◽  
O. M. Dinets

Aim. Detailed examination of different studies showed that the thickness of the straw second internode of soft winter wheat is not sufficient investigated. Methods. The article presents the results of an experiment for the study of the formation and the variability of the trait thickness of the straw second internode (TS-2M) in different soft winter wheat (Triticum aestivum L.) varieties and breeding lines. There are forty one wheat varieties of different origin presented in this study. Results. It was established that the trait TS-2M significantly correlated with the main yield traits. Therefore, the selection of productive genotypes in the selection process based on TS-2M is effective. Conclusions. The statistical analysis of winter wheat varieties based on the trait TS-2M showed that the level of formation and variability of this trait is genetically determined. Keywords: winter wheat, the second internode (ТS-2М), genetic coefficient of variation (CV%).


1987 ◽  
Vol 67 (3) ◽  
pp. 637-644
Author(s):  
P. A. VERSAVEL ◽  
W. E. MUIR

Spikes severed from the stem and stems crushed just below the attached spike were compared with untreated stems to determine if the drying rate of windrowed cereal crops could be increased. Moisture content of stems and unthreshed spikes were measured while crop material was dried under room conditions. Fresh cut immature and physiologically mature material, and rewetted crop material were examined in the laboratory. The stems of immature field material dried faster when crushed than un-crushed while the attached spikes showed no difference in drying rate. Crushed stems of both fresh and rewetted crop material at high initial moisture contents dried faster than uncrushed stems. Severed spikes dried faster than spikes attached to the stems. Spikes attached to crushed and uncrushed stems showed no difference in drying rate. Crushed stems gained moisture 58% faster than untreated stems. A windrower designed to crush straw stems could reduce straw moisture content significantly and reduce power requirements for the threshing mechanism. The benefit would be reduced or eliminated if rewetting conditions occurred.Key words: Drying, stem crushing, wheat, barley, Triticum aestivum L.


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