Snp single nucleotide polymorphism marker snps need

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: e desired crop variety – Marker assisted selection • Fortify food with Vitamin A precursors • Case study: Maize and Vitamin A – Lower Vitamin A deficiency related diseases 29 30 5 04/03/2013 Visually scoring key precursors is difficult Marker Assisted Selection • SNP markers that co segregate with the trait … …candidates for linkage to the genes for the trait. – SNP = single nucleotide polymorphism – Marker SNPs need not be causal • SNPs correlated with B carotene production: • Goal: – 2 5 fold higher production – Maximize carotenoids and B carotenes • But: • Incorporating these genomic regions into maize varieties could help reduce Vitamin A deficiencies – Color phenotype alone is unreliable – Difficult to quantify precursors in high throughput – If adopted by local growers • Therefore: Use genotype instead of phenotype! 31 Harjes et al. 2008, Science 319: 330 333 32 -Breeding the yellowest kernels isn't going to work to m aximize B-carotenes -However, colour is an unreliable phenotype -Incorporating the SNPs that co-segregate with the trait of Vitamin A production will reduce Vitamin A deficiencies Why do we care about genetic variation in crops? Irish Potato Famine (1845 1852) • 750,000 1 million Irish died during the famine 1. Clues to past artificial selection – 1 2 million more emigrated – On what traits did our ancestors select? • Population of Ireland fell by ~25% 2. Future improvement of crops – Is it possible to keep breeding better crops without genetic engineering? – Or is there insufficient genetic variation? • Many emigrants settled in Britain, USA & Canada – Started cultural ties that last to this day – Irish immigrants comprised ~25% of many major cities 3. Pest and pathogen management • Boston, Baltimore, Philadelphia, Toronto – Single largest ethnic group in Toronto in early 1850’s – Can we reduce crop loss to pests? 33 34 What happened? • Potatoes do not grow easily from seed • They sprout easily from the underground tuber (potato) • Leads to clonal propagation • This happens in your house if you forget about potatoes in a cabinet for too long ! • Social, economic, and religious discrimination, and colo...
View Full Document

This document was uploaded on 01/27/2014.

Ask a homework question - tutors are online