Identification of QTLs associated with spring vegetative budbreak time after dormancy release in pear (Pyrus communis L.) |
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Authors: | Gilad Gabay Yardena Dahan Yacov Izhaki Tal Isaacson Yonatan Elkind Giora Ben‐Ari Moshe A. Flaishman |
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Affiliation: | 1. Institute of Plant Sciences, Volcani Research Center, Rishon Lezion, Israel;2. The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel;3. Department of Fruit Tree Sciences, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel |
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Abstract: | Dormancy release is greatly affected by chilling unit (CU) accumulation. Lack of CU has a major impact on spring vegetative budbreak (VB). To understand the genetic mechanism governing the chilling requirement (CR), we conducted a QTL analysis of VB date in F1 population, derived from a cross between ‘Spadona’ (low CR) and ‘Harrow Sweet’ (high CR). Using a unique methodology of tree mobility, replicates of the same genotypes were exposed during the winter, over two consecutive years, to climates that differ greatly in their CU and to the same heat conditions to induce VB, in order to evaluate CR genetic impact and to distinguish it from the heat factor. Broad‐sense heritability within locations ranged from 0.62 to 0.66. Due to a strong impact of GxE interaction, it was reduced to 0.46 for the overall mean. We examined the previously discovered apple QTLs detected in linkage groups (LG) 9 and 8, based on the synteny between the species. Our analysis confirms significant QTLs in LG8 (R2 = 12%–24%) and LG9 (R2 = 20%–38%) for all locations and years |
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Keywords: | chilling requirement chilling units genotype x environment interaction linkage group marker‐assisted selection |
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