Author
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WAN, YIZHEN - Northwest Agricultural & Forestry University |
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Fazio, Gennaro |
Submitted to: Acta horticulturae
Publication Type: Proceedings Publication Acceptance Date: 12/15/2010 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The Geneva® apple rootstock breeding program has made extensive use of Malus robusta cv. Robusta 5 as a source of resistance to fire blight. Robusta 5 has also been used as the source of powdery mildew resistance by other breeding programs and a single locus Pl1 has been associated with this resistance and recently mapped on LG12 of the European Apple Framework Map [Plant Breeding 126:476-481, 2007] using a qualitative approach. We collected quantitative data on field powdery mildew resistance in 2006 and 2007 on a segregating population made up of 186 individuals from a cross between Ottawa 3 (a susceptible apple rootstock) and Robusta 5; the correlation between the two years was 0.84 (p=0.000). This quantitative data were used in combination with a molecular marker linkage map derived from the same cross to scan the genome using interval and MQM mapping in MapQTL 5 software. The result was the identification of a large QTL on the distal end of LG12 with a peak near the SSR marker CH01b12z. No other regions in the apple genome had any significant effects on resistance in this population when using Interval Mapping procedure. MQM mapping revealed a . Future plans include scanning of a BAC library containing Pl1 and utilizing existing markers for marker assisted breeding. |