Addition of rye chromosome 4R to wheat increases anther length and pollen grain number
The research identified rye chromosome 4R arms associated with good pollinator traits, and demonstrated possible use of rye genetic resources to develop elite pollinators for hybrid wheat breeding.
Bread wheat (Triticum aestivum) is a predominantly self-pollinating plant which has relatively small-sized anthers and produces a low number of pollen grains. These features limit the suitability of most wheat lines as pollinators for hybrid seed production. One strategy for improving the pollination ability of wheat is to introgress cross-pollination traits from related species. One such species is rye (Secale cereale L.), which has suitable traits such as high anther extrusion, long anthers containing large amounts of pollen and long pollen viability. Therefore, introducing these traits into wheat is of great interest in hybrid wheat breeding. Here, we investigated wheat–rye chromosome addition lines for the effects of rye chromosomes on anther and pollen development in wheat. Using a single nucleotide polymorphism genotyping array, we detected 984 polymorphic markers that showed expected syntenic relationships between wheat and rye. Our results revealed that the addition of rye chromosomes 1R or 2R reduced pollen fertility, while addition of rye chromosome 4R increased anther size by 16 % and pollen grain number by 33 %. The effect on anther length was associated with increases in both cell size and the number of endothecium cells and was attributed to the long arm of chromosome 4R. In contrast, the effect on pollen grain number was attributed to the short arm of chromosome 4R. These results indicate that rye chromosome 4R contains at least two genetic factors associated with increased anther size and pollen grain number that can favourably affect pollination traits in wheat.
KeywordsAddition Line Pollen Fertility Brachypodium Anther Length Chinese Spring Wheat
This research was supported by DuPont Agricultural Biotechnology—Pioneer Hi-Bred International, the Grains Research & Development Corporation, Australian Research Council and the State Government of South Australia. We thank Dr Gwen Mayo (Adelaide Microscopy) for supporting the microscopy work, Dr Ursula Langridge for supporting the glasshouse work, Dr Kelvin Khoo for supporting marker analysis, Ridma Jayasinghe and Dominique Jackson for technical assistance, Margaret Pallotta, Dr. Ryan Whitford and Prof Peter Langridge for their critical advice for the project, and Dr. Ian Dundas for critical reading of the manuscript.
Conflict of interest
The authors declare no conflict of interest.
The authors note that this research is performed in accordance with ethical standards of the scientific conduct.
- Athwal RS, Kimber G (1970) Anther size and pollen longevity in wheat/rye addition lines. Wheat Inf Serv 30:30–32Google Scholar
- Cavanagh CR, Chao S, Wang S, Huang BE, Stephen S, Kiani S, Forrest K, Saintenac C, Brown-Guedira GL, Akhunova A, See D, Bai G, Pumphrey M, Tomar L, Wong D, Kong S, Reynolds M, da Silva ML, Bockelman H, Talbert L, Anderson JA, Dreisigacker S, Baenziger S, Carter A, Korzun V, Morrell PL, Dubcovsky J, Morell MK, Sorrells ME, Hayden MJ, Akhunov E (2013) Genome-wide comparative diversity uncovers multiple targets of selection for improvement in hexaploid wheat landraces and cultivars. Proc Natl Acad Sci USA 110:8057–8062CrossRefPubMedCentralPubMedGoogle Scholar
- Driscoll C, Sears E (1971) Individual addition of the chromosomes of “Imperial” rye to wheat. Agronomy Abstract 1971:6Google Scholar
- D’Souza L (1970) Studies on the suitability of wheat as pollen donor for cross pollination, compared with rye, Triticale and Secalotricum. Zeitschrift für Pflanzenzuchtung 63:246–269Google Scholar
- Komsta L (2011) Outliers: tests for outliers. http://www.komsta.net/software
- Milohnic J, Jost M (1970) Pollen production and anther extrusion of wheat (Triticum aestivum L. Em Thell.). Acta Agron Hung 19:17–23Google Scholar
- Nkongolo KK, Haley SD, Kim NS, Michael P, Fedak G, Quick JS, Peairs FB (2009) Molecular cytogenetic and agronomic characterization of advanced generations of wheat × triticale hybrids resistant to Diuraphis noxia (Mordvilko): application of GISH and microsatellite markers. Genome 52:353–360CrossRefPubMedGoogle Scholar
- Pickett A (1993) Hybrid wheat results and problems. Paul Parey Scientific Publishers, BerlinGoogle Scholar
- Plaha P, Sethi GS (2000) Long anther trait of rye (Secale cereale L.)—its chromosomal location and expression in bread wheat (Triticum aestivum L.). Wheat Inf Serv 90:47–48Google Scholar
- Wang S, Wong D, Forrest K, Allen A, Chao S, Huang BE, Maccaferri M, Salvi S, Milner SG, Cattivelli L, Mastrangelo AM, Whan A, Stephen S, Barker G, Wieseke R, Plieske J, Lillemo M, Mather D, Appels R, Dolferus R, Brown-Guedira G, Korol A, Akhunova AR, Feuillet C, Salse J, Morgante M, Pozniak C, Luo MC, Dvorak J, Morell M, Dubcovsky J, Ganal M, Tuberosa R, Lawley C, Mikoulitch I, Cavanagh C, Edwards KJ, Hayden M, Akhunov E, International Wheat Genome Sequencing C (2014) Characterization of polyploid wheat genomic diversity using a high-density 90000 single nucleotide polymorphism array. Plant Biotechnol J 12:787–796CrossRefPubMedCentralPubMedGoogle Scholar
- Zeller FJ, Hsam SLK (1983) Broadening the genetic variability of cultivated wheat by utilizing rye chromatin. In: Sakamoto S (ed) Proceedings of the 6th international wheat genetics symposium. Plant Germ-Plasm Institute, Faculty of Agriculture, Kyoto University, Kyoto, Japan, pp 161–173Google Scholar