Seed Storability in Rice: Physiological Foundations, Molecular Mechanisms, and Applications in Breeding

Long-term storage of crop seeds is critical for the conservation of germplasm resources, ensuring food supply, and supporting sustainable production. Rice, as a major food staple, has a substantial stock for consumption and production worldwide. However, its food value and seed viability tend to decline during storage. Understanding the physiological responses and molecular mechanisms of aging tolerance forms the basis for enhancing seed storability in rice. This review outlines the latest progress in influential factors, evaluation methods, and identification indices of seed storability. It also discusses the physiological consequences, molecular mechanisms, and strategies for breeding aging-tolerant rice in detail. Finally, it highlights challenges in seed storability research that require future attention. This review offers a theoretical foundation and research direction for uncovering the mechanisms behind seed storability and breeding aging-tolerant rice.

Identification of QTLs for seed storability in rice under natural aging conditions using two RILs with the same parent Shennong 265

Seed storability （SS） is an important trait for agronomic production and germplasm preservation in rice （Oryza sativa L.）. Quantitative trait locus （QTL） for seed storability in three storage periods was identified using two sets of recombinant inbred lines （RILs） derived from the crosses with a colnmon female parent Shennong 265 （SN265）. Ten QTLs for seed storability were detected on chromosomes 1, 2, 3, 4, 6, 8, and 12in SL-RILs （SN265/Lijiangxingtuanheigui （LTH））, and a total of 12 QTLs were identified on chromosomes 2, 3, 4, 6, 9, and 10 in SH-RILs （SN265/Luhui 99 （LH99））in different storage periods. Among these QTLs, five major QTLs were identified in more than one storage period. The qSS3-1, qSS3-2, qSS12-1, and qSS12-2 were detected in SL-RILs. Similarly, qSS2-2, qSS2-3, qSS6-2, qSS6-3, qSS6-4, qSS9-1, and qSS9-2 were detected in SH-RILs. In addition, the maximum phenotypic variation was derived from the qSS6-1 and qSS9-2, explaining 53.58 and 29.09%, respectively, while qSS6-1 was a new stable QTL for seed storability. These results provide an opportunity for pyramiding and map-based cloning major QTLs for seed storability in rice.

Seed Storability of CIMMYT Core Wheat Germplasm Panel and Their Haplotypes in <i>Lipoxygenase</i>Locus

Seed storability (SS), also called seed longevity, is a valuable trait for seed banks and providing reliable crop seeds to farmers, which is usually negatively correlated to lipoxygenase (LOX) activity. In this study, the seed storability of 60 accessions of CIMMYT core wheat germplasm panel (CIMCOG) was investigated through artificial aging (AA) test, including three parameters relative germination potential (RGP), relative germination rate (RGR) and relative seedling vigor index (RVI). Significant positive relationships were observed among RGP, RGR and RVI. And the genotypes at three LOX activity related QTLs/genes QLpx.caas-4B, QLpx.caas-1AL and TaLOX-B1 were also identified with published trait-associated molecular markers. For QLpx.caas-4B, a total of five alleles were detected at the locus of Xgwm251, and one marker-trait association was identified for RVI. Four and two alleles were detected at the loci of QLpx.caas-1AL and TaLoxB1 that were significantly associated with RGP, RGR and RVI, respectively. A total of 9 haplotypes were detected at three lipoxygenase activity related gene loci, and the haplotype of three lipoxygenase loci showed a significant association with RGP, RGR and RVI. The haplotype of Xgwm251-125bp + Xwmc312-247bp + TaLox-B1b produced seeds with the best storability in the CIMCOG, which could benefit the breeding for wheat with good seed storability.

Advances in Physiological-biochemical and Genetic Mechanisms of Seed Aging in Rice(Oryza sativa L.)

Reasons causing or accelerating seed aging are mainly damage of mem- branes, DNA and proteins, decline of protein synthesis capacity and excessive ac- cumulation of reactive oxygen species. With the application of natural aging or artifi- cial aging methods, it was reported that quantitative trait loci （QTLs） of seed stora- bility in rice were widely distributed on the chromosomes except the 10th chromo- some. In this paper, we reviewed the progresses in the research on physiological- biochemical and genetic mechanisms of seed aging, and analyzed the existing problems and developing prospect in molecular breeding of rice with improved seed storability, in order to provide reference for the basic research and genetic improve- ment of rice seed storabUity.