Hybrid sterility and incompatibility

Watkins, A. E.

doi:10.1007/bf02983249

Cited by 107 publications

(40 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Several studies have suggested that endosperm breakdown is the major cause of seed failure in interspecific crosses once successful fertilization has occurred, with embryo death as a secondary effect (Watkins, 1932;Brink and Cooper, 1947;Stebbins, 1958;Haig and Westoby, 1991). Therefore, we investigated endosperm development in seeds from [2xAt ϫ 4xAa] and [4xAt ϫ 4xAa] pollinations to determine whether it could be related to the contrasting outcomes of these crosses.…”

Section: Endosperm Development In a Thaliana ϫ A Arenosa Seeds: Thementioning

confidence: 99%

“…However, endosperm breakdown is cited frequently as the cause of seed failure in both interploidy crosses within a species and interspecific crosses (Watkins, 1932;Brink and Cooper, 1947;Stebbins, 1958;Haig and Westoby, 1991). The endosperm is the second fertilization product in flowering plant reproduction and develops after the fusion of the two polar nuclei (sister nuclei to the egg) with a sperm nucleus.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Basis of Natural and Artificial Postzygotic Hybridization Barriers in Arabidopsis Species

2003

View full text Add to dashboard Cite

The success or failure of interspecific crosses is vital to evolution and to agriculture, but much remains to be learned about the nature of hybridization barriers. Several mechanisms have been proposed to explain postzygotic barriers, including negative interactions between diverged sequences, global genome rearrangements, and widespread epigenetic reprogramming. Another explanation is imbalance of paternally and maternally imprinted genes in the endosperm. Interspecific crosses between diploid Arabidopsis thaliana as the seed parent and tetraploid Arabidopsis arenosa as the pollen parent produced seeds that aborted with the same paternal excess endosperm phenotype seen in crosses between diploid and hexaploid A. thaliana . Doubling maternal ploidy restored seed viability and normal endosperm morphology. However, substituting a hypomethylated tetraploid A. thaliana seed parent reestablished the hybridization barrier by causing seed abortion and a lethal paternal excess phenotype. We conclude from these findings that the dominant cause of seed abortion in the diploid A. thaliana ϫ tetraploid A. arenosa cross is parental genomic imbalance. Our results also demonstrate that manipulation of DNA methylation can be sufficient to erect hybridization barriers, offering a potential mechanism for speciation and a means of controlling gene flow between species.

show abstract

Section: Endosperm Development In a Thaliana ϫ A Arenosa Seeds: Thementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Basis of Natural and Artificial Postzygotic Hybridization Barriers in Arabidopsis Species

2003

View full text Add to dashboard Cite

show abstract

“…Traditionally, triploid block has been viewed as the result of imbalances in ploidy between different seed tissues (Watkins 1932;Mü ntzing 1933). Watkins (1932) proposed that crosses in which the ploidy ratio of endosperm to embryo was 3:2 should give normal development. In contrast, deviation from this ratio, such as in progeny from 2x ϫ 4x (4:3) and 4x ϫ 2x (5:3) crosses would yield abnormal development.…”

Section: Triploid Fitnessmentioning

confidence: 99%

“…Mü ntzing (1933) proposed that any ploidy ratio of maternal tissue, endosperm, and embryo that deviated from 2:3:2 would result in incompatibility. However, based on seed development in 2x ϫ 4x crosses, Watkins (1932) concluded that normal development was not affected by the ploidy of the maternal tissue, but depended on the ratio of endosperm and embryo ploidies. Alternatively, the genomic imprinting model argues that offspring viability depends on the ratio of maternal:paternal genomes within the endosperm.…”

mentioning

confidence: 99%

Fitness Differences Among Diploids, Tetraploids, and Their Triploid Progeny in Chamerion Angustifolium: Mechanisms of Inviability and Implications for Polyploid Evolution

Burton¹,

2000

View full text Add to dashboard Cite

Abstract. Theoretical models indicate that the evolution of tetraploids in diploid populations will depend on both the relative fitness of the tetraploid and that of the diploid-tetraploid hybrids. Hybrids are believed to have lower fitness due to imbalances in either the ploidy (endosperm imbalance) or the ratio of maternal to paternal genomes in their endosperm (genomic imprinting). In this study we created diploids, tetraploids, and hybrid triploids of Chamerion angustifolium from crosses between field-collected diploid and tetraploid plants and evaluated them at six life stages in a greenhouse comparison. Diploid offspring (from 2x ϫ 2x crosses) had significantly higher seed production and lower biomass than tetraploid offspring (from 4x ϫ 4x crosses). Relative to the diploid, the cumulative fitness of tetraploids was 0.67. In general, triploids (from 2x ϫ 4x, 4x ϫ 2x crosses) had significantly lower seed production, lower pollen viability, and higher biomass than diploid individuals. Triploid offspring derived from diploid maternal parents had lower germination rates, but higher pollen production than those with tetraploid mothers. Relative to diploids, the cumulative fitness of 2x ϫ 4x triploids and 4x ϫ 2x triploids was 0.12 and 0.06, respectively, providing some support for effect of differing maternal:paternal ratios and endosperm development as a mechanism of hybrid inviability. Collectively, the data show that tetraploids exhibit an inherent fitness disadvantage, although the partial viability and fertility of triploids may help to reduce the barrier to tetraploid establishment in sympatric populations.

show abstract

“…Hybrid sterility in plants has been known for a long time (3)(4)(5)(6)(7)(8)(9)(10)(11). Cultivated rice comprises two species, Oryza sativa L. (Asian rice) and O. glaberrima Steud (African rice); O. sativa is classified further into two major types or subspecies, indica and japonica, which have been referred to as ''Hsien'' and ''Keng'' since the Han dynasty in China (12), based largely on the low affinity of fertility in their hybrids and other morphological features (3,13,14).…”

mentioning

confidence: 99%

Hybrid male sterility in rice controlled by interaction between divergent alleles of two adjacent genes

Long

Zhao

Niu

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

238

257

View full text Add to dashboard Cite

Sterility is common in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice (Oryza sativa). Although multiple loci for plant hybrid sterility have been identified, it remains unknown how alleles of the loci interact at the molecular level. Here we show that a locus for indicajaponica hybrid male sterility, Sa, comprises two adjacent genes, SaM and SaF, encoding a small ubiquitin-like modifier E3 ligase-like protein and an F-box protein, respectively. Most indica cultivars contain a haplotype SaM ؉ SaF ؉ , whereas all japonica cultivars have SaM ؊ SaF ؊ that diverged by nucleotide variations in wild rice. Male semi-sterility in this heterozygous complex locus is caused by abortion of pollen carrying SaM ؊ . This allele-specific gamete elimination results from a selective interaction of SaF ؉ with SaM ؊ , a truncated protein, but not with SaM ؉ because of the presence of an inhibitory domain, although SaM ؉ is required for this male sterility. Lack of any one of the three alleles in recombinant plants does not produce male sterility. We propose a two-gene/threecomponent interaction model for this hybrid male sterility system. The findings have implications for overcoming male sterility in inter-subspecific hybrid rice breeding.allelic interaction ͉ gamete selection ͉ hybrid sterility ͉ reproductive barrier ͉ two-gene/three-component model

show abstract

Hybrid sterility and incompatibility

Cited by 107 publications

References 23 publications

The Basis of Natural and Artificial Postzygotic Hybridization Barriers in Arabidopsis Species

The Basis of Natural and Artificial Postzygotic Hybridization Barriers in Arabidopsis Species

Fitness Differences Among Diploids, Tetraploids, and Their Triploid Progeny in Chamerion Angustifolium: Mechanisms of Inviability and Implications for Polyploid Evolution

Hybrid male sterility in rice controlled by interaction between divergent alleles of two adjacent genes

Contact Info

Product

Resources

About