This report presents results on the Walker lab efforts to use molecular breeding tools to pyramid powdery mildew resistance from different genetic backgrounds into V. viniferabased cultivars. Progress has been made on a number of fronts. We have: 1) Examined several sources of powdery mildew resistance from Muscadinia rotundifolia and evaluated parents and progeny via markers that are tightly linked to the resistance, and determined the allelic profiles of markers and alleles that are linked to the resistance for MAS; 2) Developed mapping populations with two different rotundifolia cultivars and mapped a major locus Run2.1 and Run2.2 on chromosome 18; 3) Mapped locus Ren4 from Chinese origin species V. romanetii on chromosome 18; 4) Verified the single dominant gene (locus) nature of resistance from the V. vinifera table grape, Kishmish vatkana, and tested its reliability under California environmental conditions; 5) Investigated the origin of powdery mildew resistance in vinifera-based table grape selections using the Kishmish vatkana Ren1 allelic profile, and identified five additional resistant selections that possess this unusual and very valuable vinifera-based source of powdery mildew resistance; 6) Nursery screened all vinifera-based plants that had one or both alleles of Ren1 linked markers as well as other resistant germplasm; 7) Utilized the above mentioned resistance sources to make crosses that combine resistance from rotundifolia and vinifera selections; 8) Developed a breeding population to initiate the study of V. cinerea B9 based powdery mildew resistance; and 9) Expanded a breeding population with powdery mildew resistance from the Chinese species, romanetii and conducted field evaluations. The knowledge and results gained from this work will lead to the development of wine and table grape selections with multiple powdery mildew resistance genes pyramided into a single line, and environmentally ?green? grapevines that do not require the application of fungicides to control powdery mildew.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2010-10-16 06:21:072017-10-16 06:21:49Using Marker-Assisted Selection to Introgress Powdery Mildew Resistance Genes from Different Vitis Resistance Sources into Wine Grapes