In Korea, black soybeans are traditionally consumed after cooking with rice to supplement protein and oil which are lacking in rice. Seed cooking quality including seed traits after cooking with rice, which is important for consumers, were so far not comprehensively considered during the process of breeding. In this study, we first evaluated seed quality after cooking with rice, we tested the correlation between seed cooking quality and seed water absorption ratio, and we attempted to identify the Quantitative trait locus(QTL)/gene using two recombinant inbred line (RIL) populations, i.e., Daepung × Socheong2 and Daepung × Ilpumgeomjeong. Based on phenotype and correlation analyses, the main factors affecting the hardness of soybeans cooked with rice may differ between RIL population. In the Daepung × Socheong2 RIL population, one QTL associated with seed hardness after cooking with rice was identified on chromosome 11, and Glyma.11g049600, encoding peroxidase, is proposed as a candidate gene. In the Daepung × Ilpumgeomjeong RIL population, two QTLs associated with seed hardness after cooking with rice were identified on chromosomes 7 and 19, one QTL related to seed water absorption on chromosome 3, and Glyma.19g092600 encoding pectin methylesterase inhibitor are proposed as candidate genes. This is the first study on soybean cooking quality after cooking with rice, and the locations of four related QTLs were identified. The results will be of use for future development of high-quality black soybean varieties with high consumer preference using molecular breeding methods.

In this study, genetic analysis was conducted on the inheritance of qualitative traits, such as leaf color, flower color, seed size, and seed hardness, in the F₂ population derived from the cross between var. frutescens and var. crispa. As determined by the separation pattern of each trait in the F₂ population, F₂ plants with a green color were more common than those with a purple color on the leaf surface, whereas F₂ plants with a purple color were more common than those with a green color on the reverse side of the leaf. For flower color, more F₂ plants were observed to have a white color. For seed size, more F₂ plants were observed to have a seed size of above 2 mm, and for seed hardness, more F₂ plants were observed to have characteristics of seed hardness. Our examination of the genetic separation ratios with respect to Mendel’s law of genetics revealed that three traits, leaf color (surface and reverse side) and flower color, did not follow the separation ratio of 1:2:1, and the seed size did not follow the segregation ratio of 3:1, but seed hardness was found to follow the separation ratio of 3:1. The results of this study are expected to provide basic information to help understand the genetic segregation of leaf and seed characteristics in the F₂ population derived from the cross between var. frutescens and var. crispa, and also to provide useful information for breeding studies to assist the development of varieties of Perilla crop.

The ‘Jangwon’ chestnut (Castanea crenata Siebold & Zucc.) was released from Korean native chestnut trees by the Korea Forest Research Institute (KFRI) to develop cultivars with desirable nut characteristics such as high sweetness and easy peeling in 2010. This cultivar was first selected from a natural population in 2001, and the preliminary trials for evaluation were carried out from 2007 to 2009. The harvest time of ‘Jangwon’ was the second week of September and the total yield of an 8-year-old tree was 3.9 kg. Also, ‘Jangwon’ was a suitable cultivar for making roasted peeled products because its soluble solid content was 17.5%, kernel hardness was 9.6 kg·cm², and pellicle removability was 98.6%, which were much higher than those of the control cultivar, Arima. Furthermore, this cultivar is suitable as a pollinator for the improvement of pellicle removability of other chestnut trees.