ABSTRACT
Potato tuber shape, size, and specific gravity are important agronomic traits in the russet market class of potatoes with an impact on quality, consistency, and product recovery of processed foods such as French fries. Therefore, identifying genetic regions associated with the three traits through quantitative trait locus/loci (QTL) analysis is a crucial process in the subsequent development of marker-assisted selection for use in potato breeding programs. QTL analysis was conducted on a tetraploid mapping population consisting of 190 individuals derived from the cross between two russet-skinned parents, Palisade Russet and the breeding clone ND028673B-2Russ. Field data collected over a 2-year period and used in the QTL analyses included tuber length-width and width-depth ratios that were obtained using a digital caliper. The width-depth ratio provided an assessment of the "flatness" of a tuber, which is of importance in potato processing. To cross-validate the accuracy and differences among tuber shape measurement methods, a trained evaluator also assessed the identical tubers based on 1-5 scale (compressed to long) visual assessment method. Furthermore, the weights of analyzed tubers and specific gravities were also collected during the phenotyping process for each mapping clone. A major tuber shape QTL was consistently observed on chromosome 10 with both the length-width ratio and visual assessments. On chromosome 4, a significant QTL for tuber shape from the visual assessment phenotypic data was also detected. Additionally, a tuber shape-related QTL on chromosome 6 was also detected from the length-width ratio data from 2020. Chromosome 2 was also identified as having a significant QTL for the width-depth ratio, which is of importance in influencing the flatness of a tuber. One significant QTL for tuber weight (i.e., tuber size) was observed on chromosome 5, and a significant QTL for specific gravity was found on chromosome 3. These significant and major QTL should be useful for developing marker-assisted selection for more efficient potato breeding.
ABSTRACT
Uma das estratégias utilizadas pelos melhoristas de batata é a eliminação de um grande número de clones nas primeiras gerações de seleção, para reduzir os custos e o trabalho de manutenção e multiplicação destes. O objetivo deste trabalho foi avaliar o uso da correlação canônica entre caracteres de tubérculos plantados, relacionados com os colhidos, para auxiliar a seleção precoce de clones de batata. Foram conduzidos três ensaios em diferentes épocas, na área experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria. Foram avaliados os tubérculos-semente e aqueles colhidos de 10 progênies de batata. Os caracteres utilizados para a análise da correlação canônica foram: o comprimento, o maior e o menor diâmetro e a massa fresca. Com o uso da correlação canônica, observou-se que há relação das diferentes características dos tubérculos plantados e daqueles colhidos. O comprimento apresentou a maior associação entre os tubérculos plantados e colhidos. Tubérculos compridos resultam na produção de tubérculos alongados.
A potato breeding strategy is applied in early selection to discard the majority of potato clones, to reduce costs and efforts for maintenance and multiplication. The objective of this research was to test the canonical correlation of seeded tuber traits and harvested tubers to assist the early selection of potato clones. Three experiments in different seasons were carried out in the experimental area of the Horticultural Department of the Federal University of Santa Maria. Seeded and harvested tubers of ten potato progeny were evaluated. The tuber traits length, larger and smaller diameter, and fresh weight were submitted to canonical correlation analysis. The canonical correlation showed a trait relationship between potato seeds and their production. The largest association was tuber length. Therefore, long seed tubers produce elongated tubers as well.
