Cholani Weebadde

Identification of QTL associated with flower and runner production in octoploid strawberry (Fragaria×ananassa)

BACKGROUND: Understanding the genetics of flowering in the strawberry (Fragaria × ananassa) will aid in the development of breeding strategies. OBJECTIVE: To search for quantitative trait loci (QTL) associated with remontancy and weeks of flowering in the strawberry. METHODS: Previously collected phenotypic data from two non-remontant ‘Honeoye’ × remontant ‘Tribute’ strawberry populations and simple sequence repeats (SSR) markers were used to search for QTL associated with repeat flowering, weeks of flowering and runner production, as well as the ability to produce flowers and runners at 17, 20 and 23 ◦ C. RESULTS: As was discovered in other studies, we found a major QTL that regulated remontancy and weeks of flowering on homeologous linkage group IV of ‘Tribute’. This QTL also had a negative effect on runner production and a positive influence on flower production under high temperatures. A number of additional QTL were discovered that significantly (LOD >3.0) influenced flower and runner production. CONCLUSIONS: Remontancy/non-remontancy is controlled by a major gene/locus and several minor modifying ones.

Public Availability of a Genotyped Segregating Population May Foster Marker Assisted Breeding (MAB) and Quantitative Trait Loci (QTL) Discovery: An Example Using Strawberry

Much of the cost associated with marker discovery for marker assisted breeding (MAB) can be eliminated if a diverse, segregating population is generated, genotyped, and made available to the global breeding community. Herein, we present an example of a hybrid, wild-derived family of the octoploid strawberry that can be used by other breeding programs to economically find and tag useful genes for MAB. A pseudo test cross population between two wild species of Fragaria virginiana and F. chiloensis (FVC 11) was generated and evaluated for a set of phenotypic traits. A total of 106 individuals in the FVC 11 were genotyped for 29,251 single nucleotide polymorphisms (SNPs) utilizing a commercially available, genome-wide scanning platform (Affymetrix Axiom IStraw90TW). The marker trait associations were deduced using TASSEL software. The FVC 11 population segregating for daughters per mother, inflorescence number, inflorescence height, crown production, flower number, fruit size, yield, internal color, soluble solids, fruit firmness, and plant vigor. Coefficients of variations ranged from 10% for fruit firmness to 68% for daughters per mother, indicating an underlying quantitative inheritance for each trait. A total of 2,474 SNPs were found to be polymorphic in FVC 11 and strong marker trait associations were observed for vigor, daughters per mother, yield and fruit weight. These data indicate that FVC 11 can be used as a reference population for quantitative trait loci detection and subsequent MAB across different breeding programs and geographical locations.

Forces influencing developing country views of agricultural biotechnology: an analysis of training programme participants’ perceptions

Agricultural biotechnology is expanding around the world, but societal acceptance remains an important issue. Michigan State University (MSU) has developed and implemented an agricultural biotechnology short course for developing countries. Four courses were taught to regional groups in 2002–2003 and eight more were taught to geographically diverse groups in 2004–2008. One half day of each course was devoted to issues related to biotechnology acceptance. The participants discussed the pro-GM and anti-GM forces in their countries. Scientists were the top ranked pro-GM force and information was the top anti-GM force. Regional differences were found between forces such as food security and economics. Possible temporal differences included a rising influence of farmers on the pro-GM side and a falling influence of environmental NGOs on the anti-GM side.