UNCOVERING GENES CONTROLLING APPLE TREE ARCHITECTURE AND FRUIT QUALITY

Dougherty, Laura Elizabeth

UNCOVERING GENES CONTROLLING APPLE TREE ARCHITECTURE AND FRUIT QUALITY

dc.contributor.author	Dougherty, Laura Elizabeth
dc.contributor.chair	Xu, Kenong
dc.contributor.committeeMember	Scanlon, Michael J.
dc.contributor.committeeMember	Yu, Haiyuan
dc.date.accessioned	2020-06-23T18:03:50Z
dc.date.available	2022-01-17T07:00:17Z
dc.date.issued	2019-12
dc.description	282 pages
dc.description	Supplemental file(s) description: Table S5.1. List of 952 Malus accessions allelotyped with markers ACS1 and CAPS866 and CAPS870, Table S4.8. Genes expressed in the c2 and c3 regions, Table S4.7. Differentially expressed genes (DEGs) among the three phenotypes columnar, standard1 (Std1) and standard2 (Std2), Table S2.10. List of expressed genes in the W2 region according to the new reference genome (Daccord et al. 2017), Table S2.9. List of expressed genes in the W region according to the new reference genome (Daccord et al. 2017), Table S2.8. List of expressed genes in the W2 region, Table S2.7 List of expressed genes in the W region.
dc.description.abstract	As the world population increases, there is a need to produce more food in limited land space. There is a strong need to optimize food production while reducing space, cost and food waste. This can be achieved with high density plantings, automated harvesting and food with longer shelf life. Apples are one of the most widely grown foods in the world and contain necessary nutrients. Apple trees have distinct, naturally occurring growth habits that include standard, weeping and columnar. Understanding the genetic mechanisms behind these growth habits can lead to more trees planted per acre and mechanized harvesting. In this dissertation, weeping (W) was mapped to chromosome 13 and MdLazy1 was identified as a strong candidate gene underlying the weeping growth habit. Genetic mapping within a segregating columnar population revealed two recessive repressors regions of the columnar growth habit. Apple fruit are stored in cold storage after harvest allowing them to be available year round for consumption. A major problem with fruit storage is the softening of fruit over time and a decrease in quality. In this dissertation, alleles of two ethylene synthesis genes MdACS1 and MdACS3a were identified in 952 cultivars. Post-harvest storage studied on 131 cultivars combined with allelic genotypes revealed beneficial allelic combinations of the two genes that reduced fruit soften. Research conducted and summarized in this dissertation addresses apple tree architecture and fruit quality. The genetic regions identified, makers analyzed, markers created and genes characterized increase understanding of genetic mechanisms underlying weeping and columnar growth habit and fruit softening. This research helps address solutions to optimize food production, while also providing fruit breeder’s information that can be utilized when creating new superior apple cultivars.
dc.identifier.doi	https://doi.org/10.7298/cdw4-1219
dc.identifier.other	Dougherty_cornellgrad_0058F_11849
dc.identifier.other	http://dissertations.umi.com/cornellgrad:11849
dc.identifier.uri	https://hdl.handle.net/1813/70124
dc.language.iso	en
dc.subject	Apples
dc.subject	Genetics
dc.subject	Malus
dc.subject	trait mapping
dc.title	UNCOVERING GENES CONTROLLING APPLE TREE ARCHITECTURE AND FRUIT QUALITY
dc.type	dissertation or thesis
dcterms.license	https://hdl.handle.net/1813/59810
thesis.degree.discipline	Horticulture
thesis.degree.level	Doctor of Philosophy
thesis.degree.name	Ph. D., Horticulture