Karyotype mosaicism in early generation synthetic hexaploid wheats

It is known that both the number and the structure of somatic chromosomes can vary in early generation hexaploid wheats. The phenomenon is generally assumed to arise as a result of the meiotic instability characteristic of freshly created allopolyploids. Here, an analysis of the somatic karyotype of a set of 33 early generation synthetic hexaploid wheats has revealed that variation, taking the form of sub-chromosomal fragments and inter-chromosomal translocations, can also arise in somatic tissue. A possible explanation for the observations was that karyotypic instability in early generation hexaploid wheat probably occurs not just during sporogenesis, but also in somatic tissue. However, other factors such as the use of nitrous oxide during the experiments could also cause the chromosome variations, and additional experimentation would be required to determine the most likely.

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Origin of host-specificity resistance genes of common wheat against non-adapted pathotypes of Pyricularia oryzae inferred from D-genome diversity in synthetic hexaploid wheat lines

Journal of General Plant Pathology ◽

10.1007/s10327-021-00990-2 ◽

2021 ◽

Author(s):

Yoshihiro Inoue ◽

Trinh Thi Phuong Vy ◽

Soichiro Asuke ◽

Yoshihiro Matsuoka ◽

Yukio Tosa

Keyword(s):

Host Specificity ◽

Common Wheat ◽

Resistance Genes ◽

Hexaploid Wheat ◽

Pyricularia Oryzae ◽

Synthetic Hexaploid Wheat ◽

Genome Diversity ◽

D Genome ◽

Synthetic Hexaploid ◽

Wheat Lines

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Additive genetic variance and covariance between relatives in synthetic wheat crosses with variable parental ploidy levels

Genetics ◽

10.1093/genetics/iyaa048 ◽

2021 ◽

Vol 217 (2) ◽

Author(s):

L E Puhl ◽

J Crossa ◽

S Munilla ◽

P Pérez-Rodríguez ◽

R J C Cantet

Keyword(s):

Hexaploid Wheat ◽

Variance Components ◽

Bayesian Model ◽

Synthetic Hexaploid Wheat ◽

Data Sets ◽

Hierarchical Bayesian Model ◽

Additive Variance ◽

Ploidy Levels ◽

Breeding Values ◽

Synthetic Hexaploid

Abstract Cultivated bread wheat (Triticum aestivum L.) is an allohexaploid species resulting from the natural hybridization and chromosome doubling of allotetraploid durum wheat (T. turgidum) and a diploid goatgrass Aegilops tauschii Coss (Ae. tauschii). Synthetic hexaploid wheat (SHW) was developed through the interspecific hybridization of Ae. tauschii and T. turgidum, and then crossed to T. aestivum to produce synthetic hexaploid wheat derivatives (SHWDs). Owing to this founding variability, one may infer that the genetic variances of native wild populations vs improved wheat may vary due to their differential origin and evolutionary history. In this study, we partitioned the additive variance of SHW and SHWD with respect to their breed origin by fitting a hierarchical Bayesian model with heterogeneous covariance structure for breeding values to estimate variance components for each breed category, and segregation variance. Two data sets were used to test the proposed hierarchical Bayesian model, one from a multi-year multi-location field trial of SHWD and the other comprising the two species of SHW. For the SHWD, the Bayesian estimates of additive variances of grain yield from each breed category were similar for T. turgidum and Ae. tauschii, but smaller for T. aestivum. Segregation variances between Ae. tauschii—T. aestivum and T. turgidum—T. aestivum populations explained a sizable proportion of the phenotypic variance. Bayesian additive variance components and the Best Linear Unbiased Predictors (BLUPs) estimated by two well-known software programs were similar for multi-breed origin and for the sum of the breeding values by origin for both data sets. Our results support the suitability of models with heterogeneous additive genetic variances to predict breeding values in wheat crosses with variable ploidy levels.

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The influence of high-molecular-weight subunits of glutenin from Triticum tauschii on flour quality of synthetic hexaploid wheat

Journal of Cereal Science ◽

10.1016/s0733-5210(87)80016-4 ◽

1987 ◽

Vol 5 (2) ◽

pp. 129-138 ◽

Cited By ~ 38

Author(s):

Evans S. Lagudah ◽

Finlay Macritchie ◽

Gerald M. Halloran

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Hexaploid Wheat ◽

Synthetic Hexaploid Wheat ◽

Flour Quality ◽

Triticum Tauschii ◽

Synthetic Hexaploid

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Effects of drought and high temperature stress on synthetic hexaploid wheat

Functional Plant Biology ◽

10.1071/fp11245 ◽

2012 ◽

Vol 39 (3) ◽

pp. 190 ◽

Cited By ~ 110

Author(s):

Gautam P. Pradhan ◽

P. V. Vara Prasad ◽

Allan K. Fritz ◽

Mary B. Kirkham ◽

Bikram S. Gill

Keyword(s):

High Temperature ◽

Temperature Stress ◽

Hexaploid Wheat ◽

High Temperature Stress ◽

Synthetic Hexaploid Wheat ◽

Combined Stress ◽

Wheat Genotypes ◽

Synthetic Hexaploid ◽

Effects Of Drought ◽

Days After Anthesis

Drought and high temperature often occurs simultaneously, causing significant yield losses in wheat (Triticum aestivum L.). The objectives of this study were to: (i) quantify independent and combined effects of drought and high temperature stress on synthetic hexaploid wheat genotypes at anthesis and at 21 days after anthesis; and (ii) determine whether responses to stress varied among genotypes. Four synthetic hexaploid and two spring wheat genotypes were grown from emergence to anthesis (Experiment I) and emergence to 21 days after anthesis (Experiment II), with full irrigation and 21/15°C day/night temperature. Thereafter, four treatments were imposed for 16 days as (a) optimum condition: irrigation + 21/15°C, (b) drought stress: withhold irrigation + 21/15°C, (c) high temperature stress: irrigation + 36/30°C and (d) combined stress: withhold irrigation + 36/30°C. Results indicated a decrease in leaf chlorophyll, individual grain weight and grain yield in an increasing magnitude of drought < high temperature < combined stress. There were 69, 81 and 92% grain yield decreases in Experiment I and 26, 37 and 50% in Experiment II under drought, high temperature and combined stress respectively. Synthetic hexaploid wheat genotypes varied in their response to stresses. Genotypes ALTAR 84/AO’S’ and ALTAR 84/Aegilops tauschii Coss. (WX 193) were least affected by combined stress in Experiments I and II respectively. Overall, combined effect of drought + high temperature stress was more detrimental than the individual stress and the interaction effect was hypo-additive in nature.

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