Breeding with Exotic Germplasm in Sunflower (Helianthus Annuus) PDF Download

Author: Eric Von Hoeft
Publisher:
ISBN: 9781339550589
Category :
Languages : en
Pages :

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Book Description
Exotic germplasm holds considerable promise as a source of novel variation to improve agronomic characters in elite breeding pools where genetic diversity has been limited by selective sweeps in line development or crop domestication. Unfortunately, exotic germplasm typically carries a large number of unfavorable alleles that give rise to linkage drag in segregating populations, making it unsuitable for variety improvement with traditional selection methods. Linkage drag masks the detection of favorable alleles underlying complex agronomic characters by negatively impacting phenotypic performance. Consequently, the exploitation of exotic germplasm has traditionally been limited to the detection and utilization of characters controlled by relatively few alleles with dominant, co-dominant or highly additive gene action. If favorable alleles underlying complex agronomic characters could be detected in exotic germplasm sources, opportunities to exploit them in elite breeding pools through marker-assisted selection or other methods may be improved. An Advanced Inter-mated Recombinant Inbred Line (AI-RIL) population was employed to construct a genetic map and detect QTL underlying complex agronomic characters in four independent testcross populations of sunflower (Helianthus annuus). Testcross hybrids were evaluated for plant height, flowering time, seed harvest moisture, seed test weight, ring count per capitulum and grain yield. Significant QTL for each character were detected in each test cross population independently and across populations by employing the BLUP over testcross datasets. A genome-wide association study was employed to further interrogate marker-trait associations and elucidate candidate genes regulating these characters. Finally, a genomic selection model was developed to predict performance of testcross hybrids based on the estimated allele effects represented in AI-RIL genotypes and to evaluate genomic selection as a tool for the exploitation of favorable alleles from exotic germplasm sources.