The International Union for the Protection of New Varieties of Plants (UPOV) promotes an effective system of plant variety protection and encourages the development of new varieties of plants. This international convention was initiated to standardize the system efforts and strengthen policy. The establishment of cultivar discrimination system is very important to distinguish varieties between domestic and foreign agricultural products. It is necessary for the protection of breeders’rights. In addition, it will help for more efficient and quality management of plant breeding. This study was conducted to identify and group rice varieties based on agro-morphological characteristics such as plant height, panicle length, number of tillers, culm length, leaf length, leaf width, leaf pigments and flag leaf angles. Using these parameters, statistical analysis classified a total of 243 rice varieties bred in Korea into four groups. Most rice varieties did not exhibit anthocyanin pigments on the leaves particularly on the first leaf, leaf blade, leaf sheath and auricle, except for varieties classified as black rice. Results of phylogenetic and principal component analysis (PCA) indicated that these varieties formed three largely distinct clusters according to their ecotype and morphological differentiation. This result would be useful in rice varietal identification for the protection of breeders’variety rights.

Low-molecular-weight glutenin subunits (LMW-GS) play a crucial role in the processing quality of wheat flour. They are encoded multi gene family located at the Glu-A3, Glu-B3 and Glu-D3 on the short arm of chromosome 1A, 1B and 1D respectively. Typical LMW-GSs are composed of three parts including a short N-terminal domain, a relatively short repetitive domain and a C-terminal domain. Further, typical LMW-GS sequences are divided into LMW-s, LMW-m and LMW-i types, on the basis of the first amino acid of the mature proteins (serine, methionine and isoleucine, respectively). Although it is known that the allelic variation of LMW-GSs affect the properties of dough, it is still not clear which LMW-GSs confer better bread-making quality because of the larger number of expressed subunits and their overlapping mobility with abundant gliadin proteins. Therefore, it is important to characterize LMW-GS genes and develop functional markers to identify different LMW-GS alleles for application in wheat breeding. In this review, we discuss the various aspects of LMW-GS, including their structural characteristics, the development of marker, relationship between LMW-GSs and bread wheat quality, and genetic engineering of the LMW-GSs.