title: High-Throughput Phenotyping of Sorghum Plant Height Using an Unmanned Aerial Vehicle and Its Application to Genomic Prediction Modeling.
abstract: Genomics-assisted breeding methods have been rapidly developed with novel technologies such as next-generation sequencing, genomic selection and genome-wide association study. However, phenotyping is still time consuming and is a serious bottleneck in genomics-assisted breeding. In this study, we established a high-throughput phenotyping system for sorghum plant height and its response to nitrogen availability; this system relies on the use of unmanned aerial vehicle (UAV) remote sensing with either an RGB or near-infrared, green and blue (NIR-GB) camera. We evaluated the potential of remote sensing to provide phenotype training data in a genomic prediction model. UAV remote sensing with the NIR-GB camera and the 50th percentile of digital surface model, which is an indicator of height, performed well. The correlation coefficient between plant height measured by UAV remote sensing (PHUAV) and plant height measured with a ruler (PHR) was 0.523. Because PHUAVwas overestimated (probably because of the presence of taller plants on adjacent plots), the correlation coefficient between PHUAVand PHRwas increased to 0.678 by using one of the two replications (that with the lower PHUAVvalue). Genomic prediction modeling performed well under the low-fertilization condition, probably because PHUAVoverestimation was smaller under this condition due to a lower plant height. The predicted values of PHUAVand PHRwere highly correlated with each other (r= 0.842). This result suggests that the genomic prediction models generated with PHUAVwere almost identical and that the performance of UAV remote sensing was similar to that of traditional measurements in genomic prediction modeling. UAV remote sensing has a high potential to increase the throughput of phenotyping and decrease its cost. UAV remote sensing will be an important and indispensable tool for high-throughput genomics-assisted plant breeding.
authors.affiliation: Laboratory of Biometry and Bioinformatics, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Kakeru
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Institute for Sustainable Agro-ecosystem Services, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: Air4D Co., Ltd. Tokyo, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Arai
authors.affiliation: Laboratory of Plant Molecular Genetics, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takanashi
authors.affiliation: Laboratory of Biometry and Bioinformatics, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kajiya-Kanegae
authors.affiliation: Bioinformatics Laboratory, Department of Life Sciences, School of Agriculture, Meiji University Kanagawa, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Bioinformatics Laboratory, Department of Life Sciences, School of Agriculture, Meiji University Kanagawa, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yano
authors.affiliation: Earthnote Co., Ltd. Okinawa, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tokunaga
authors.affiliation: Laboratory of Plant Nutrition and Fertilizers, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Laboratory of Plant Molecular Genetics, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsutsumi
authors.affiliation: Laboratory of Biometry and Bioinformatics, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Iwata
keywords: UAV remote sensing; genomic prediction; high-throughput phenotyping; near-infrared (NIR); sorghum plant height