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RESEARCH ARTICLE
Contents Vol 59(5)

Rebirth of synthetic hexaploids with global implications for wheat improvement

Abdul Mujeeb-Kazi A E , Alvina Gul A , Muhammad Farooq B , Sumaira Rizwan C and Iftikhar Ahmad D
+ Author Affiliations
- Author Affiliations

A National Institute of Biotechnology & Genetic Engineering (NIBGE), Faisalabad, Pakistan.

B Biotechnology Department, University of Karachi, Karachi, Pakistan.

C Department of Biological Sciences, Quaid-e-Azam University, Islamabad, Pakistan.

D National Agricultural Research Center (NARC), Islamabad, Pakistan.

E Corresponding author. Email: m.kazi@cgiar.org

Australian Journal of Agricultural Research 59(5) 391-398 https://doi.org/10.1071/AR07226
Submitted: 14 June 2007  Accepted: 30 October 2007   Published: 12 May 2008

Abstract

Aegilops tauschii (syn.Triticum tauschii (Coss.) Schmalh., syn. Ae. squarrosa auct. Non L., 2n = 2x = 14, DD genome), with its numerous accessions and wide distribution, provides unparallelled genetic diversity for addressing global wheat production constraints through genetic improvement. From our working collection of ~750 Ae. tauschii accessions, hybridisation efforts produced 1014 synthetic hexaploid combinations (2n = 6x = 42, AABBDD), resulting from chromosome doubling of the F1 hybrids between elite Triticum turgidum L. s. lat. cultivars and Ae. tauschii accessions. The extensive production of synthetic hexaploids represents a step-wise progression over 2 decades in the generation of a valuable resource of user-friendly genetic diversity. The synthetic germplasm has been validated, maintained, screened, formed into targetted stress-related subsets for focused utilisation, and been allowed global distribution for use in pre-breeding/breeding with advent into molecular technologies. Abundant synthetic hexaploids with different Ae. tauschii accessions have been identified from their screening for yield per se, and various biotic/abiotic stresses. Encouraging diversity data have been obtained for key abiotic constraints such as drought, salinity, heat, and water-logging. A similar response was prevalent for the salient biotic stresses such as fusarium head scab, spot blotch, septoria leaf blotch, and karnal bunt. Global distribution of the selected synthetics has further added valuable information for several other stress constraints and led to utilisation of the synthetic diversity for molecular investigations. The superiority of the primary synthetics has been transferred with ease via pre-breeding/breeding to conventional bread wheat cultivars and varietal releases have started globally. The success and status of the D genome diversity are the focus of this paper and we are optimistic that researchers will devise additional strategies to harness other genomes as efficiently by adding on new technologies that ensure wheat production security in the decades ahead.

Additional keywords: synthetic hexaploid wheats, interspecific hybridisation, Aegilops tauschii, genetic diversity, biotic stresses, abiotic stresses.


Acknowledgments

The senior author acknowledges CIMMYT where the bulk of the data reported in this paper were generated and are in program files in Mexico with the Wheat Wide Cross program at El-Batan. The germplasm across various stress attributes has been registered in Crop Science, stored in the gene bank in Fort Collins, CO, USA, and in CIMMYT’s gene bank. Following the senior author’s retirement from CIMMYT in October 2004 the synthetic-based germplasm was officially shared and has since been maintained and used in wheat breeding in Pakistan, under the leadership of the senior author. Germplasm details and all registered genetic stocks can be obtained from CIMMYT as well as from A. Mujeeb-Kazi (m.kazi@cgiar.org).


References


Alonso LC, Kimber G (1984) Use of restitution nuclei to introduce alien genetic variation into hexaploid wheat. Z. Pflanzenzuchtg 92, 185–189. open url image1

Cox TS, Hatchett JH (1994) Hessian fly resistance gene H26 transferred from Triticum tauschii to common wheat. Crop Science 34, 958–960. open url image1

Cox TS, Raupp WJ, Gill BS (1994) Leaf rust-resistance genes Lr41, Lr42 and Lr43 transferred from Triticum tauschii to common wheat. Crop Science 34, 339–349. open url image1

Cox TS, Raupp WJ, Wilson DL, Gill BS, Leath S, Bockus WW, Browder LE (1992) Resistance to foliar diseases in a collection of Triticum tauschii germplasm. Plant Disease 76, 1061–1064. open url image1

Cox TS, Sears RG, Bequette RK (1995a) Use of winter wheat × Triticum tauschii backcross populations for germplasm evaluation. Theoretical and Applied Genetics 90, 571–577.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Cox TS, Sears RG, Bequette RK, Martin TJ (1995b) Germplasm enhancement in winter wheat × Triticum tauschii backcross populations. Crop Science 35, 913–919. open url image1

Dewey DR (1984) The genomic system of classification as a guide to intergeneric hybridization with the perennial Triticeae. In ‘Gene manipulation in plant improvement’. (Ed. JP Gustafson) pp. 259–265. (Plenum Press: New York)

Eyal Z , Scharen AL , Prescott JM , van Ginkel M (1987) ‘The Septoria diseases of wheat: concepts and methods of disease management.’ (CIMMYT: Mexico)

Gill BS, Raupp WJ (1987) Direct gene transfers from Aegilops squarrosa L. to hexaploid wheat. Crop Science 27, 445–450. open url image1

Gill BS, Raupp WJ, Sharma HC, Browder LE, Hatchett JH, Harvey TL, Moseman JG, Waines JG (1986) Resistance in Aegilops squarrosa to wheat leaf rust, wheat powdery mildew, greenbug, and Hessian fly. Plant Disease 70, 553–556.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Gill BS, Sharma HC, Raupp WJ, Browder LE, Hatchett JH, Harvey TL, Moseman JG, Waines JG (1985) Evaluation of Aegilops species for resistance to powdery mildew, wheat leaf rust, Hessian fly, and greenbug. Plant Disease 69, 314–316. open url image1

Gorham J, Hardy C, Wyn Jones RG, Joppa L, Law C (1987) Chromosomal location of a K+/Na+ discrimination character in the D genome of wheat. Theoretical and Applied Genetics 74, 584–588.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Harlan J, de Wet JMJ (1971) Towards a rational classification of cultivated plants. Taxon 20, 509–517.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Kawahara T , Takumi S , Matsuoka Y , Mori N , Yasui Y (2003) Tauschii core collection, a powerful tool for utilizing wheat D genome genetic resources. In ‘10th International Wheat Genetics Symposium’. Paestum, Italy. (Eds NE Pogna, M Romano, EA Pogna, G Galterio) pp. 584–586. (S.I.M.I., Via N. Nisco 3/A-00179: Roma, Italy)

Kihara H (1944) Discovery of the DD-analyser, one of the ancestors of vulgare wheats. Agricultural Horticulture 19, 889–890. open url image1

Kimber G , Feldman M (1987) Wild wheat: an introduction. Special Report 353, College of Agriculture, University of Missouri – Columbia. pp. 129–131.

Ma H, Singh RP, Mujeeb-Kazi A (1995) Suppression/expression of resistance to stripe rust in synthetic hexaploid wheat (Triticum turgidum × Triticum tauschii). Euphytica 83, 87–93.
| Crossref | GoogleScholarGoogle Scholar | open url image1

McFadden ES, Sears ER (1946) The origin of Triticum spelta and its free-threshing relatives. Journal of Heredity 37, 81–116. open url image1

Mujeeb-Kazi A (2000) An analysis of the use of haploidy in wheat improvement. Intergeneric hybrids in wheat. In ‘Application of Biotechnologies to Wheat Breeding. Proceedings of Conference’. La Estanzuela, Uruguay. (Eds MM Kohli, M Francis) pp. 49–56. (INIA: La Estanzuela, Colonia, Uruguay)

Mujeeb-Kazi A (2001) Synthetic hexaploids for bread wheat improvement. In ‘International Triticeae IV Symposium’. Cordoba, Spain. (Eds P Hernandez, MT Moreno, JI Cubero, A Martin) pp. 193–199. (Junta de Andalucia, Consejeria de Agricultura y Pesca, 2002)

Mujeeb-Kazi A (2003) New genetic stocks for durum and bread wheat improvement. In ‘10th International Wheat Genetics Symposium’. Paestum, Italy. (Eds NE Pogna, M Romano, EA Pogna, G Galterio) pp. 772–774. (S.I.M.I., Via N. Nisco 3/A-00179: Roma, Italy)

Mujeeb-Kazi A (2006) ‘Utilization of genetic resources for bread wheat improvement. CRC Series.’ (Eds RJK Singh, PP Jauhar) pp. 61–97. (Taylor and Francis Group: Baton Rouge, FL)

Mujeeb-Kazi A , Delgado R , Cano S , Rosas V , Cortes A (2000 a) Alien genetic diversity for wheat improvement: focus on scab resistance. In ‘2000 National Fusarium Head Blight Forum Proceedings’. (Eds RW Ward, SM Canty, J Lewis, L Siler) pp. 220–224. (Michigan State University: Michigan, MI)

Mujeeb-Kazi A, Fuentes-Davilla G, Villareal RL, Cortes A, Rosas V, Delgado R (2001) Registration of 10 synthetic hexaploid wheat and six bread wheat germplasms resistant to Karnal bunt. Crop Science 41, 1652–1653. open url image1

Mujeeb-Kazi A, Gilchrist LI, Villareal RL, Delgado R (2000b) Registration of 10 wheat germplasms resistant to Septoria tritici leaf blotch. Crop Science 40, 590–591. open url image1

Mujeeb-Kazi A , Hettel GP (1995) Utilising wild grass biodiversity in wheat improvement: 15 years of wide cross research at CIMMYT. CIMMYT Research Report No. 2, CIMMYT, Mexico, D.F. pp. 1–140.

Mujeeb-Kazi A, Miranda JL (1985) Enhanced resolution of somatic chromosome constrictions as an aid to identifying intergeneric hybrids among some Triticeae. Cytologia 50, 701–709. open url image1

Mujeeb-Kazi A , Rajaram S (2002) Transferring alien genes from related species and genera for wheat improvement. In ‘Bread Wheat Improvement and Production’. pp. 199–215. (FAO: Rome)

Mujeeb-Kazi A, Rosas V, Roldan S (1996) Conservation of the genetic variation of Triticum tauschii (Coss.) Schmalh. (Aegilops squarrosa auct. Non L.) in synthetic hexaploid wheats (T. turgidum L. s.lat. × T. tauschii; 2n = 6x = 42, AABBDD) and its potential utilization for wheat improvement. Genetic Resources and Crop Evolution 43, 129–134.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Pestsova EG , Borner A , Roder MS (2001) Development of wheat D-genome introgression lines assisted by microsatellite markers. In ‘International Triticeae IV Symposium’. (Eds P Hernandez, MT Moreno, JI Cubero, A Martin) pp. 207–210. (Junta de Andalucia, Consejeria de Agricultura y Pesca, 2002)

Pestsova EG, Ganal MW, Roder MS (2000) Isolation and mapping of microsatellite markers specific for the D genome of bread wheat. Genome 43, 689–697.
| Crossref | GoogleScholarGoogle Scholar | PubMed | open url image1

Plaschke J, Ganal MW, Roder MS (1995) Detection of genetic diversity in closely related bread wheat using micorsatellite markers. Theoretical and Applied Genetics 91, 1001–1007.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Rajaram S (2001) Prospects and promise of wheat breeding in the 21st century. Euphytica 119, 3–15.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Roder MS, Korzun V, Gill BS, Ganal MW (1998a) The physical mapping of microsatellite markers in wheat. Genome 41, 278–283.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Roder MS, Korzun V, Wendehake K, Plaschke J, Tixier MH, Leroy P, Ganal MW (1998b) A microsatellite map of wheat. Genetics 149, 1–17.
| PubMed |
open url image1

Shah S, Gorham J, Forster B, Wyn Jones RG (1987) Salt tolerance in the Triticeae: the contribution of the D genome to cation selectivity in hexaploid wheat. Journal of Experimental Botany 38, 254–269.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Sharma HC (1995) How wide can a wide cross be? Euphytica 82, 43–64.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Valkoun JJ (2001) Wheat pre-breeding using wild progenitors. Euphytica 119, 17–23.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Valkoun J , Dostal J , Kucerova D (1990) Triticum × Aegilops hybrids through embryo culture. In ‘Biotechnology in Agriculture and Forestry’. Vol. 13 Wheat. (Ed. YPS Bajaj) pp. 152–166. (Springer-Verlag: Berlin, Heidelberg)

Villareal RL , Mujeeb-Kazi A (2003) Genetic diversity and wheat improvement for sustainable agriculture. In ‘Agronomy Abstracts’. (American Society of Agronomy: Madison, WI) (CD-ROM)