Direct and indirect selection for drought tolerance in alien tetraploid wheat x durum wheat crosses

Hakimi, Amin Al; Monneveaux, P.; Nachit, M. M.

doi:10.1007/978-94-011-4896-2_49

Cited by 9 publications

(10 citation statements)

References 17 publications

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“…Most resurrection plants, which grow in deserts and are capable of withstanding very high levels of desiccation, are polyploid (Bartels and Salamini 2001;Rodriguez et al 2010). Several studies have shown that a plant's drought tolerance increases with its ploidy level (Al Hakimi et al 1998;Xiong et al 2006). For example, Ramsey (2011) compared the drought tolerances of hexaploid and tetraploid individuals belonging to Achillea borealis and found the hexaploids were more tolerant.…”

Section: Environmental Stress and Polyploidymentioning

confidence: 99%

The thermodynamics of protein aggregation reactions may underpin the enhanced metabolic efficiency associated with heterosis, some balancing selection, and the evolution of ploidy levels

Ginn

2017

Progress in Biophysics and Molecular Biology

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Identifying the physical basis of heterosis (or "hybrid vigor") has remained elusive despite over a hundred years of research on the subject. The three main theories of heterosis are dominance theory, overdominance theory, and epistasis theory. Kacser and Burns (1981) identified the molecular basis of dominance, which has greatly enhanced our understanding of its importance to heterosis. This paper aims to explain how overdominance, and some features of epistasis, can similarly emerge from the molecular dynamics of proteins. Possessing multiple alleles at a gene locus results in the synthesis of different allozymes at reduced concentrations. This in turn reduces the rate at which each allozyme forms soluble oligomers, which are toxic and must be degraded, because allozymes co-aggregate at low efficiencies. The model developed in this paper can explain how heterozygosity impacts the metabolic efficiency of an organism. It can also explain why the viabilities of some inbred lines seem to decline rapidly at high inbreeding coefficients (F > 0.5), which may provide a physical basis for truncation selection for heterozygosity. Finally, the model has implications for the ploidy level of organisms. It can explain why polyploids are frequently found in environments where severe physical stresses promote the formation of soluble oligomers. The model can also explain why complex organisms, which need to synthesize aggregation-prone proteins that contain intrinsically unstructured regions (IURs) and multiple domains because they facilitate complex protein interaction networks (PINs), tend to be diploid while haploidy tends to be restricted to relatively simple organisms.

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Section: Environmental Stress and Polyploidymentioning

confidence: 99%

The thermodynamics of protein aggregation reactions may underpin the enhanced metabolic efficiency associated with heterosis, some balancing selection, and the evolution of ploidy levels

Ginn

2017

Progress in Biophysics and Molecular Biology

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“…The three T. turgidum accessions as well as T. polonicum pseudochrysospermum and T. carthlicum filuginosum showed high Δ and grain yield values, especially under the stress conditions of 1995 (Table 1). These species can readily be crossed with T. durum to give high proportions of seeds and fertile hybrids (Al Hakimi et al. 1998).…”

Section: Resultsmentioning

confidence: 99%

“…Consequently, drought tolerance improvement is one of the major objectives of durum wheat breeders in this region. Increased attention has been paid to the close genetic relatives of wheat, and particularly to the tetraploid Triticum (Al Hakimi et al. 1998), as a major source of genetic diversity.…”

Section: Introductionmentioning

confidence: 99%

Carbon Isotope Discrimination and Grain Yield Variations among Tetraploid Wheat Species Cultivated under Contrasting Precipitation Regimes

Merah

Deléens

Hakimi

et al. 2001

J Agronomy Crop Science

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Nineteen accessions belonging to six tetraploid wheat species were evaluated and compared for carbon isotope discrimination and grain yield during two successive cropping seasons (1995 and 1996) under Mediterranean rainfed conditions. The two seasons differed markedly in precipitation regime. A wide variation for the measured traits was observed among the 19 accessions for carbon isotope discrimination and grain yield in both years. Significant differences were also noted between species accessions for Δ and grain yield. In both years, Triticum timopheevi (AG genome) showed lower Δ values than the other tetraploid species (all carrying the AB genome). Positive correlations were observed between Δ and grain yield in both years. The use of carbon isotope discrimination as an indirect selection criterion for yield under stress and the potential benefits of some alien tetraploid species in improving drought tolerance in durum wheat are discussed.

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“…In addition to changes in morphology and anatomy, polyploids can also exhibit a number of novel physiological (e.g., drought stress or disease resistance) and cultivation (e.g., flowering, post-harvest quality) characteristics, which are potentially valuable for commercial success in agricultural and horticultural crops (Al Hakimi et al 1998;Riddle et al 2006;Xiong et al 2006). As a consequence, polyploids can be better adapted to broader ecological amplitudes (Soltis and Soltis 2000).…”

Section: Applications Of In Vitro Chromosome Doubling In Plant Breedingmentioning

confidence: 98%

Mitotic chromosome doubling of plant tissues in vitro

Dhooghe¹,

Laere²,

Eeckhaut³

et al. 2010

Plant Cell Tiss Organ Cult

337

258

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In vitro chromosome doubling can be induced by several antimitotic agents. The most commonly used are colchicine, oryzalin and trifluralin. The process of induced chromosome doubling in vitro consists of a typical succession of sub-processes, including an induction phase and a confirmation protocol to measure the rate of success. The induction step depends on a large number of variables: media, antimitotic agents, explant types, exposure times and concentrations. Flow cytometry is the pre-eminent method for evaluation of the induced polyploidization. However, alternative confirmation methods, such as chromosome counts and morphological observations, are also used. Since polyploidization has many consequences for plant growth and development, chromosome doubling has been intensively studied over the years and has found its way to several applications in plant breeding. This review gives an overview of the common methods of chromosome doubling in vitro, the history of the technique, and progress made over the years. The applications of chromosome doubling in a broader context are also discussed.

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Direct and indirect selection for drought tolerance in alien tetraploid wheat x durum wheat crosses

Cited by 9 publications

References 17 publications

The thermodynamics of protein aggregation reactions may underpin the enhanced metabolic efficiency associated with heterosis, some balancing selection, and the evolution of ploidy levels

The thermodynamics of protein aggregation reactions may underpin the enhanced metabolic efficiency associated with heterosis, some balancing selection, and the evolution of ploidy levels

Carbon Isotope Discrimination and Grain Yield Variations among Tetraploid Wheat Species Cultivated under Contrasting Precipitation Regimes

Mitotic chromosome doubling of plant tissues in vitro

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