Date of Graduation

Summer 2022

Degree

Master of Science in Plant Science (Biology)

Department

Biology

Committee Chair

Laszlo G. Kovacs

Abstract

The root system of the plant plays a vital role in water and nutrient uptake. Native North American grapevines adapted to a broad range of climatic and soil conditions, which led to the evolution of diverse root system architecture (RSA) within the Vitis genus. Despite the importance of RSA in viticulture, little is known about the genetic basis of the RSA in grapevine. I used novel root phenotyping tool, RhizoVision Analyzer to characterize the root system of 208 genotypes of an F1 grapevine progeny obtained from a cross between Vitis rupestris Scheele B38 and Vitis riparia Michx. HP-1. Dormant cuttings from these genotypes were grown for five weeks in controlled atmospheric conditions, and then twenty-six RSA traits were extracted from 2-D root images. Forty-seven female parental cuttings were also rooted, which enabled calculation of environmental and genetic variance in the F1 population. High heritability was found for number of root tips, total root length, and holes. Principal component analysis (PCA) conducted with diverse traits, demonstrated that PC1 explained 40.03% variation and it correlated well with medium angle frequency. A negative correlation was found between average root diameter and the number of root tips and total root length of the root system. Total root length, number of root tips, maximum and median number of roots were found to be significantly different between the female parent and the F1 population. Quantitative trait locus (QTL) analysis was conducted and genetic regions influencing total root length, maximum width, and surface area were identified in chromosome 2. Calcium, magnesium and zinc were found to be positively correlated with traits that increase the size of the root system. Canonical correspondence analysis (CCA) showed that manganese was associated with coarse diameter frequency and number of root tips, whereas iron was associated with medium angle frequency. The findings presented here offer insights into the genetic makeup of RSA in grapevine and provide breeders with actionable information to develop grapevine varieties that are better adapted to conditions brought by climate change.

Keywords

root system architecture, 2-D imaging, Vitis rupestris, Vitis riparia, QTL, linkage mapping, F1 hybrids

Subject Categories

Botany | Cell and Developmental Biology | Genetics | Molecular Genetics | Plant Biology | Viticulture and Oenology

Copyright

© Sujan Thapa

Download

Open Access

Share

COinS