Fast and accurate selection is essential for breeding to cope with rapid climate changes and a steeply increasing population. Consequently, technologies for high-throughput phenotyping (HTP) are emerging. These technologies, unlike conventional phenotyping methods, enable us to evaluate agronomic traits in a fast and massive manner. Thus, the HTP facility was built to acquire and analyze crop images using RGB sensors at the National Institute of Agricultural Sciences, Republic of Korea. By testing various conditions to acquire images, we determined the conditions for phenotyping using the RGB sensor as follows: exposure 30,000 ms, gamma 75, and gain 100 using LED lights in a blue background. Based on this condition, images from 96 individual plants of rice Dongjin cultivar were obtained every week to measure plant height and shoot area, which are directly associated with yield. The results obtained from the image analysis were compared with the manually collected results. The r² value between the projected plant height obtained from image analysis and the plant height obtained from manual measurement was 0.989. Furthermore, the r² value between the projected shoot area obtained from image analysis and the shoot area obtained from manual measurement was 0.981. These results show that image analysis is highly reliable and can be used for crop phenotyping. Therefore, we expect that the new method we developed will be used for breeding in the near future.

Perilla is an oilseed crop cultivated in Korea since ancient times. Due to the high α-linolenic acid content in perilla, perilla seed oil can easily become rancid. α-Linolenic acid is synthesized by two enzymes, endoplasmic reticulum-localized Δ15 desaturase (FAD3) and chloroplast-localized Δ15 desaturase (FAD7) in vivo. In order to lower the α-linolenic acid content of the seed oil without disturbing plant growth, we tried to suppress the expression of only the FAD3 gene using RNA interference, whilst maintaining the expression of the FAD7 gene. Seventeen transgenic plants with herbicide (Basta™) resistance were obtained by Agrobacterium-mediated transformation using hypocotyls of perilla plants. The transgenic plants were firstly confirmed by treatment with 0.3% (v/v) Basta™ herbicide, and the expression of FAD3 was measured by Northern blot analysis. The α-linolenic acid content was 10-20%, 30-40%, and 60% in two, seven, and three of the twelve T₁ transgenic perilla plants which had enough seeds to be analyzed for fatty acid composition, respectively. Analysis of the fatty acid composition of T₂ progeny seeds from T₁ plants with the lowest α-linolenic acid content showed that the homozygous lines had 6-10% α-linolenic acid content and the heterozygous lines had 20-26% α-linolenic acid content. It is expected that the reduction in α-linolenic acid content in perilla seed oil will prevent rancidity and can be utilized for the production of high-value functional ingredients such as high γ-linolenic acid.