A 1BL/1RS translocation contributing to kernel length increase in three wheat recombinant inbred line populations

The 1BL/1RS wheat-rye translocation has been widely utilized in wheat genetic improvement and breeding programs. Our understanding on the effects of the 1BL/1RS translocation on wheat kernel size (e.g. length and width) is limited despite of numerous studies reporting about the effects on kernel weight. Here, we identified a wheat 1BL/1RS translocation line 88-1643 with higher kernel length (KL) using fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH) and molecular markers. To detect the possible role of the 1BL/1RS translocation in KL, kernel width (KW), and thousand-kernel weight (TKW), three recombinant inbred line (RIL) populations were constructed by crossing 88-1643 and three other wheat lines. As expected, the results showed that the values of KL in lines carrying 1RS were significantly higher than those carrying 1BS in three RIL populations at multiple environments, indicating that a major and stably expressed allele or gene responsible for increasing KL is most likely located on 1RS from 88-1643. Additionally, in one RIL population, the increased KL contributed significantly to the increase in TKW. Collectively, the 1BL/1RS translocation reported here is of interest to reveal molecular mechanism of the gene controlling KL and will be useful for improving wheat yield.