scholarly journals Understanding meiosis and the implications for crop improvement

2009 ◽  
Vol 36 (7) ◽  
pp. 575 ◽  
Author(s):  
Jason A. Able ◽  
Wayne Crismani ◽  
Scott A. Boden

Over the past 50 years, the understanding of meiosis has aged like a fine bottle of wine: the complexity is developing but the wine itself is still young. While emphasis in the plant kingdom has been placed on the model diploids Arabidopsis (Arabidopsis thaliana L.) and rice (Orzya sativa L.), our research has mainly focussed on the polyploid, bread wheat (Triticum aestivum L.). Bread wheat is an important food source for nearly two-thirds of the world’s population. While creating new varieties can be achieved using existing or advanced breeding lines, we would also like to introduce beneficial traits from wild related species. However, expanding the use of non-adapted and wild germplasm in cereal breeding programs will depend on the ability to manipulate the cellular process of meiosis. Three important and tightly-regulated events that occur during early meiosis are chromosome pairing, synapsis and recombination. Which key genes control these events in meiosis (and how they do so) remains to be completely answered, particularly in crops such as wheat. Although the majority of published findings are from model organisms including yeast (Saccharomyces cerevisiae) and the nematode Caenorhabditis elegans, information from the plant kingdom has continued to grow in the past decade at a steady rate. It is with this new knowledge that we ask how meiosis will contribute to the future of cereal breeding. Indeed, how has it already shaped cereal breeding as we know it today?

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basavalingayya K. Swamy ◽  
Ravikumar Hosamani ◽  
Malarvizhi Sathasivam ◽  
S. S. Chandrashekhar ◽  
Uday G. Reddy ◽  
...  

AbstractHypergravity—an evolutionarily novel environment has been exploited to comprehend the response of living organisms including plants in the context of extra-terrestrial applications. Recently, researchers have shown that hypergravity induces desired phenotypic variability in seedlings. In the present study, we tested the utility of hypergravity as a novel tool in inducing reliable phenotype/s for potential terrestrial crop improvement applications. To investigate, bread wheat seeds (UAS-375 genotype) were subjected to hypergravity treatment (10×g for 12, and 24 h), and evaluated for seedling vigor and plant growth parameters in both laboratory and greenhouse conditions. It was also attempted to elucidate the associated biochemical and hormonal changes at different stages of vegetative growth. Resultant data revealed that hypergravity treatment (10×g for 12 h) significantly enhanced root length, root volume, and root biomass in response to hypergravity. The robust seedling growth phenotype may be attributed to increased alpha-amylase and TDH enzyme activities observed in seeds treated with hypergravity. Elevated total chlorophyll content and Rubisco (55 kDa) protein expression across different stages of vegetative growth in response to hypergravity may impart physiological benefits to wheat growth. Further, hypergravity elicited robust endogenous phytohormones dynamics in root signifying altered phenotype/s. Collectively, this study for the first time describes the utility of hypergravity as a novel tool in inducing reliable root phenotype that could be potentially exploited for improving wheat varieties for better water usage management.


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.


2020 ◽  
Vol 10 (5) ◽  
pp. 253-258
Author(s):  
S.O. Kovalchuk ◽  
S.I. Voloschuk ◽  
N.A. Kozub

The aim of work was the estimation of valuable traits of bread wheat breeding lines, obtained from interspecies crosses with wild Aegilops and Triticum species growing in a condition of the Forest-Steppe of Ukraine. We used the seed proteins electrophoresis in PAAG for confirmation of the presence of rye seed storage components in the wheat parental lines genomes. The biochemical compositions of seeds had determined by the infrared spectroscopy method. As a result of researching from the set of 600 breeding lines were selected best lines with increased grain yield from 1 m2, with high protein content in grain, disease resistance, and winter hardiness significantly exceeded the standard variety Polesskaya-90. All lines have high and moderate resistance against diseases: Powdery Mildew, Brown Rust, Septoria Blotch. Based on obtained data had selected breeding lines, which were promising sources of single and complex agronomically valuable traits for bread wheat breeding and genetic researches.


Genome ◽  
2015 ◽  
Vol 58 (8) ◽  
pp. 385-390 ◽  
Author(s):  
Jian Ma ◽  
Shang Gao ◽  
Jiri Stiller ◽  
Qian-Tao Jiang ◽  
Xiu-Jin Lan ◽  
...  

Chromosome translocation is an important driving force in shaping genomes during evolution. Detailed knowledge of chromosome translocations in a given species and its close relatives should increase the efficiency and precision of chromosome engineering in crop improvement. To identify genes flanking the breakpoints of translocations and inversions as a step toward identifying breakpoints in bread wheat, we systematically analysed genes in the Brachypodium genome against wheat survey sequences and bin-mapped ESTs (expressed sequence tags) derived from the hexaploid wheat genotype ‘Chinese Spring’. In addition to those well-known translocations between group 4, 5, and 7 chromosomes, this analysis identified genes flanking the three pericentric inversions on chromosomes 2B, 4B, and 5A. However, numerous chromosomal rearrangements reported in early studies could not be confirmed. The genes flanking the breakpoints reported in this study are valuable for isolating these breakpoints.


2020 ◽  
Vol 21 (21) ◽  
pp. 8296
Author(s):  
Lyudmila Zotova ◽  
Nasgul Shamambaeva ◽  
Katso Lethola ◽  
Badr Alharthi ◽  
Valeriya Vavilova ◽  
...  

Down-regulator associated protein, DrAp1, acts as a negative cofactor (NC2α) in a transcription repressor complex together with another subunit, down-regulator Dr1 (NC2β). In binding to promotors and regulating the initiation of transcription of various genes, DrAp1 plays a key role in plant transition to flowering and ultimately in seed production. TaDrAp1 and TaDrAp2 genes were identified, and their expression and genetic polymorphism were studied using bioinformatics, qPCR analyses, a 40K Single nucleotide polymorphism (SNP) microarray, and Amplifluor-like SNP genotyping in cultivars of bread wheat (Triticum aestivum L.) and breeding lines developed from a cross between spelt (T. spelta L.) and bread wheat. TaDrAp1 was highly expressed under non-stressed conditions, and at flowering, TaDrAp1 expression was negatively correlated with yield capacity. TaDrAp2 showed a consistently low level of mRNA production. Drought caused changes in the expression of both TaDrAp1 and TaDrAp2 genes in opposite directions, effectively increasing expression in lower yielding cultivars. The microarray 40K SNP assay and Amplifluor-like SNP marker, revealed clear scores and allele discriminations for TaDrAp1 and TaDrAp2 and TaRht-B1 genes. Alleles of two particular homeologs, TaDrAp1-B4 and TaDrAp2-B1, co-segregated with grain yield in nine selected breeding lines. This indicated an important regulatory role for both TaDrAp1 and TaDrAp2 genes in plant growth, ontogenesis, and drought tolerance in bread and spelt wheat.


2012 ◽  
Vol 40 (2) ◽  
pp. 254 ◽  
Author(s):  
Reza DARVISHZADEH ◽  
Iraj BERNOUSI

Inter simple sequence repeat (ISSR) markers were used to characterize and assess genetic diversity of Iranian bread wheat (Triticum aestivum L.) using 101 cultivars and breeding lines. Twenty-three ISSR primers amplified a total of 267 loci, of which 224 (83.9%) were polymorphic among the genotypes. The percentage of polymorphic loci (PPL) for primers ranged from 54% (UBC808) to 100% (441, A12 and UBC820). The mean of expected heterozygosity (He) for the primers varied from 0.26 (UBC808, UBC827 and A14) to 0.48 (A12, 441). The PPL, He, Shannon’s information index (I), and number of effective alleles (Ne) for breeding lines were slightly higher than those of cultivars. The Dice similarity coefficient for the germplasm ranged from 0.76 (between two breeding lines) to 0.91 (between two breeding lines). The dendrogram grouped samples in four main clusters; most cultivars were placed into the same cluster close to each other with regard to their geographic origin. The genotypes in different groups might be used as potential parents in bread wheat breeding programs. Also, a high level of genetic similarity detected in this collection may demonstrate the narrow genetic base of Iranian wheat germplasm.


2017 ◽  
Vol 340 (6-7) ◽  
pp. 307-313 ◽  
Author(s):  
Babak Abdollahi Mandoulakani ◽  
Shilan Nasri ◽  
Sahar Dashchi ◽  
Sorour Arzhang ◽  
Iraj Bernousi ◽  
...  

2014 ◽  
Vol 67 (1) ◽  
pp. 3-11 ◽  
Author(s):  
T. Ayalneh ◽  
T. Letta ◽  
M. Abinasa

Abstract The success of crop improvement and production activities can be enhanced with scientific information generated form genotype-environment interactions. GEI reduces the association between phenotype and genotype which result in relative ranking and stability differences of genotypes across environments. This study were conducted with the objective to identify stable, and adaptable bread wheat genotypes under various environments. Eighteen genotypes were tested across nine environments for two years on randomized block design of three replication. Plot size of 1.2 m × 2.5 m and 20cm spacing between rows were used. All recommended agronomic practices and managements were applied uniformly. Data were collected on plot basis and converted to ton ha-1. and analyzed with appropriate statistical software for stability parameters. Combined analysis over nine environments showed, variety Tuse (HAR-1407) ranked first in mean yield(3.11ton × ha-1), and K-6295–4A ranked second (3.01 ton × ha-1) and Dashen came third(2.98 ton ha-1). Analysis of AMMI model showed that the first principal component, PCA 1 explained 53.72% of the interaction sum of squares while the second principal component, PCA 2 explained 17.61% interaction sum of squares. Ecovalence(Wi) analysis showed that G2 (Sofumar(HAR-1889)), G4 (Kubsa(HAR-1685)), G5 (Tura(HAR-1407)), G7 (Galema (HAR-604)), G12 (Wabe (HAR-710)), almost equally the lowest ecovalence that evidenced less fluctuation across environment and found to be stable.


2015 ◽  
Vol 7 (1) ◽  
pp. 443-446
Author(s):  
Rajender Singh ◽  
Ratan Tiwari ◽  
Davinder Sharma ◽  
Vinod Tiwari ◽  
Indu Sharma

Mutagenesis is one of the powerful genetic strategies for crop improvement programmes. A chemically induced mutated genetic resource for detecting novel variations by Targeting Induced Local Lesions IN Genomes (TILLING) has been developed in recently released bread wheat (Triticum aestivum) cultivar DPW621-50. A total of 3,478 M2 plants were evaluated for plant height, number of tillers/plant, thousand grain weight, number of seeds/spike and grain yield/plant. A large variation was observed for all the traits. The highest frequency (52.2%) of lines had similar height between 91-100 cm to the non-mutagenized DPW 621-50 control followed by 28.9% of lines with height between 81-90 cm. A large variation was observed in number of tillers/plant which ranged from 1-35 tillers/plant. The highest frequency (32.09%) lines had 31-40 seeds/spike followed by 29.84% lines with 41-50 seeds/spike. Few lines (0.35%) had more than 70 seeds/spike with normal seed size as their thousand grain weight ranged between 34.82-43.82g. Chlorophyll deficient, grassy type and sterile mutants were also observed. This population may serve as new genetic resource for functional genomics studies and novel variants for different traits in elite germplasm can be made available to the plant breeders for wheat improvement.


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