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,...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 <em>QLpx.caas</em>-4<em>B</em>, <em>QLpx.caas</em>-1<em>AL</em> and <em>TaLOX</em>-<em>B</em>1 were also identified with published trait-associated molecular markers. For <em>QLpx.caas</em>-4<em>B</em>, a total of five alleles were detected at the locus of <em>Xgwm</em>251, and one marker-trait association was identified for RVI. Four and two alleles were detected at the loci of <em>QLpx.caas</em>-1<em>AL</em> and <em>TaLoxB</em>1 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 <em>Xgwm</em>251<sub>-125<em>bp</em> </sub>+ <em>Xwmc</em>312<sub>-247<em>bp</em></sub> + <em>TaLox</em>-<em>B</em>1<em>b</em> produced seeds with the best storability in the CIMCOG, which could benefit the breeding for wheat with good seed storability.展开更多
Many organisms have dormant stages with an extension of their life span to increase longevity, and deeper dormancy is usually related to greater longevity. In cereal crops, seed dormancy is significantly associated wi...Many organisms have dormant stages with an extension of their life span to increase longevity, and deeper dormancy is usually related to greater longevity. In cereal crops, seed dormancy is significantly associated with pre-harvest sprouting tolerance during seed development, as seed longevity is a valuable trait for seed banks and providing reliable crop seeds to farmers. In this study, we evaluated both seed dormancy and longevity in bread wheat based on germination and artificial aging tests. According to phenotypic clustering analysis, relative germination rate/potential and relative seedling vigor index were more effective to indicate seed longevity than relative electrical conductivity in wheat, while all the four investigated phenotypes of relative germination potential, relative germination rate, germination index and degree of seed dormancy fit well as a reflex of wheat seed dormancy. In the correlation analysis, the germination level of newly harvested grain negatively reflected its degree of seed dormancy, while the germination ability of grain after artificial aging reflected its seed longevity. However, in contrast to the current opinion in plant, seed dormancy was significantly negatively correlated to seed longevity in our study, and it was not an accidental phenomenon, for that the majority of accessions with high degree of seed dormancy had short seed longevity. To our knowledge, this is the first to report the negative association between seed dormancy and longevity in cereal crops. It would lead to further concerns about how to breed wheat with both prolonged seed longevity and deep dormancy to avoid pre-harvest sprouting.展开更多
文摘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 <em>QLpx.caas</em>-4<em>B</em>, <em>QLpx.caas</em>-1<em>AL</em> and <em>TaLOX</em>-<em>B</em>1 were also identified with published trait-associated molecular markers. For <em>QLpx.caas</em>-4<em>B</em>, a total of five alleles were detected at the locus of <em>Xgwm</em>251, and one marker-trait association was identified for RVI. Four and two alleles were detected at the loci of <em>QLpx.caas</em>-1<em>AL</em> and <em>TaLoxB</em>1 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 <em>Xgwm</em>251<sub>-125<em>bp</em> </sub>+ <em>Xwmc</em>312<sub>-247<em>bp</em></sub> + <em>TaLox</em>-<em>B</em>1<em>b</em> produced seeds with the best storability in the CIMCOG, which could benefit the breeding for wheat with good seed storability.
文摘Many organisms have dormant stages with an extension of their life span to increase longevity, and deeper dormancy is usually related to greater longevity. In cereal crops, seed dormancy is significantly associated with pre-harvest sprouting tolerance during seed development, as seed longevity is a valuable trait for seed banks and providing reliable crop seeds to farmers. In this study, we evaluated both seed dormancy and longevity in bread wheat based on germination and artificial aging tests. According to phenotypic clustering analysis, relative germination rate/potential and relative seedling vigor index were more effective to indicate seed longevity than relative electrical conductivity in wheat, while all the four investigated phenotypes of relative germination potential, relative germination rate, germination index and degree of seed dormancy fit well as a reflex of wheat seed dormancy. In the correlation analysis, the germination level of newly harvested grain negatively reflected its degree of seed dormancy, while the germination ability of grain after artificial aging reflected its seed longevity. However, in contrast to the current opinion in plant, seed dormancy was significantly negatively correlated to seed longevity in our study, and it was not an accidental phenomenon, for that the majority of accessions with high degree of seed dormancy had short seed longevity. To our knowledge, this is the first to report the negative association between seed dormancy and longevity in cereal crops. It would lead to further concerns about how to breed wheat with both prolonged seed longevity and deep dormancy to avoid pre-harvest sprouting.
