Soybean is a shortday plant which is very sensitive to photoperiod, but cultivars can grow across the world in a wide range of latitudes from 50° N to 35° S. This is due to the rich genetic variability in the genes or the photoperiod of the flowering time. Moreover, Flowering time, as an important ecological trait, is closely related to maturity and final yield.
Thus far, 11 major genes controlling the flowering time and maturity have been reported in soybean: E1, E2, E3, E4, E5, E6, E7, E8, E9, E10, and J. Among them, a number of major genes and QTLs have been selected during the breeding process. However, due to the complexity of the photoperiod, there are still many important genes controlling flowering time that have not been discovered, and the genetic basis of soybean adaptation to diverse latitudes is still not clear. Researchers try their best to elucidate new genes controlling flowering time in soybean.
Recently, an Assistant Researcher WANG Feifei from Northeast Institute of Geography and Agroecology of the Chinese Academy of Sciences, collaborating with Prof. KONG Fanjiang`s team from the Guangzhou University, for investigating the new flowering time genes in soybean. The study were published in Molecular breeding and The Crop Journal.
The researchers grew the RIL population of 171 individuals derived from the cross between Minsoy(E1e2E3E4) and Archer(e1ase2E3E4). And They identified three QTLs on chromosomes 5, 6, and 7 from the RIL population. Of these QTLs, one QTL on chromosome 6 is E1 gene. One QTL on chromosome 7 is called as E11, as a new dominant locus since there are no known flowering time genes located on chromosome 7 in soybean. E11 accounted for ~ 15% of the total phenotypic variation over 2 years, and controlled early flowering. The gene symbol E11e11 had been approved by the soybean genetic committee.
Additionally, The researchers identified 4 LNK2 (Nightlight-induced and clock-regulated 2) genes regulating flowering stage in soybean. Under LD conditions, knock-down of the four LNK2 genes shortens flowering time.
These findings will be valuable in improving our understanding of the mechanism for the flowering time and molecular assisted breeding in soybean.
Zhaobo Li, Qun Cheng, Zhuoran Gan et al., Multiplex CRISPR/Cas9-mediated knockout of soybean LNK2 advances flowering time. The Crop Journal, 2020, https://doi.org/10.1016/j.cj.2020.09.005
Feifei Wang, Haiyang Nan, Liyu Chenet al., A new dominant locus, E11, controls early flowering time. Molecular breeding, 2019, 39:70
