Rice grain quality is a complex trait that includes processing, appearance, eating, cooking, and nutrition components. The amylose content (AC) in the rice endosperm affects the eating and cooking quality along with the appearance of milled rice. In this study, four indica rice varieties with different ACs were used to study the factors affecting endosperm transparency along with the physical and chemical characteristics and eating quality of translucent endosperm varieties. Endosperm transparency was positively correlated with water content and negatively correlated with the cumulative area of cavities within starch granules. The indica landrace 28Zhan had a translucent endosperm and exhibited good taste. Based on starch fine structure analysis, long-chain amylopectin and the B2 chain of amylopectin might be major contributors to the good taste and relatively slow digestion of this landrace.

Hybrid rice technology has been used for more than 50 years, and eating and cooking quality (ECQ) has been a major focus throughout this period. Waxy (Wx) and alkaline denaturation (ALK) genes have received attention owing to their pivotal roles in determining rice characteristics. However, despite significant effort, the ECQ of restorer lines (RLs) has changed very little. By contrast, obvious changes have been seen in inbred rice varieties (IRVs), and the ECQ of IRVs is influenced by Wx, which reduces the proportion of Wx^a and increases the proportion of Wx^b, leading to a decrease in amylose content (AC) and an increase in ECQ. Meanwhile, ALK is not selected in the same way. We investigated Wx alleles and AC values of sterile lines of female parents with the main mating combinations in widely used areas. The results show that almost all sterile lines were Wx^a-type with a high AC, which may explain the low ECQ of hybrid rice. Analysis of hybrid rice varieties and RLs in the last 5 years revealed serious homogenisation among hybrid rice varieties.

Starch serves as a crucial storage substance in both cereal crops and root/tuber crops, with its composition and properties determining the quality of storage organs. The Waxy (Wx) gene, encoding a key enzyme in starch biosynthesis, plays a pivotal role in this metabolic pathway. However, existing reviews seldom systematically elaborate on Wx gene regulatory mechanisms from the perspective of intrinsic molecular networks. Focusing on the model crop rice, this article synthesizes research advances in Wx-mediated starch biosynthesis regulation over the past decade. We analyze the structural features of the Wx gene and factors influencing its regulatory function during starch synthesis. In conclusion, future research directions are proposed to provide references for Wx gene studies in other crops, as well as theoretical foundations for rice varietal improvement and molecular design breeding.

Rice is one of the world’s most abundant food crops. The amylose content is a key factor affecting the production of high-quality rice. The commonly used method for determining the amylose content is the Iodine-Starch colorimetric method. Due to the limitations of traditional iodine colorimetric methods, this experiment provides a simple high-throughput method (SSDM) for determining amylose content. Using rice varieties with different genetic backgrounds as experimental materials, the accuracy and practicality of the new method were explored to improve measurement efficiency and simplify the operation process. The results demonstrated a strong correlation (R = 0.9998) between the absorbance values and amylose content, with a relative deviation of less than 1.2%. It showed good repeatability, with a variation range of 0.43% to 1.63%. The experiment takes a short time and can measure 96 samples at once. Therefore, while ensuring the accuracy of experimental results, the high-throughput measurement method improves the efficiency of measuring amylose content. This has important practical significance for early screening and identification of excellent individuals in rice quality genetic breeding programs.