Abstract
BackgroundFlowering time and maturity are among the most important adaptive traits in soybean (Glycine max (L.) Merill). Flowering Locus T (FT) family genes function as key flowering integrators, with flowering-promoting members GmFT2a/GmFT5a and flowering-inhibiting members GmFT4/GmFT1a antagonistically regulating vegetative and reproductive growth. However, to date, the relations between natural variations of FT family genes and the diversity of flowering time and maturity in soybean are not clear. Therefore, we conducted this study to discover natural variations in FT family genes in association with flowering time and maturity.ResultsTen FT family genes, GmFT1a, GmFT1b, GmFT2a, GmFT2b, GmFT3a, GmFT3b, GmFT4, GmFT5a, GmFT5b and GmFT6, were cloned and sequenced in the 127 varieties evenly covering all 14 known maturity groups (MG0000-MGX). They were diversified at the genome sequence polymorphism level. GmFT3b and GmFT5b might have experienced breeding selection in the process of soybean domestication and breeding. Haplotype analysis showed that a total of 17 haplotypes had correlative relationships with flowering time and maturity among the 10 FT genes, namely, 1a-H3, 1b-H1, 1b-H6, 1b-H7, 2a-H1, 2a-H3, 2a-H4, 2a-H9, 2b-H3, 2b-H4, 2b-H6, 2b-H7, 3b-H4, 5a-H1, 5a-H2, 5a-H4 and 5b-H1. Based on the association analysis, 38 polymorphic sites had a significant association with flowering time at the level of p < 0.01.ConclusionsSome natural variations exist within the 10 FT family genes, which might be involved in soybean adaptation to different environments and have an influence on diverse flowering time and maturity. This study will facilitate the understanding of the roles of FTs in flowering and maturity.
Highlights
Flowering time and maturity are among the most important adaptive traits in soybean (Glycine max (L.) Merill)
Sequence polymorphisms of the 10 soybean Flowering Locus T (FT) family genes The results of sequence analysis showed that the 10 soybean FT family genes diversified in sequence polymorphism, with the polymorphism sites ranging from 8 (GmFT4) to 129 (GmFT1a) (Table 1)
Haplotypes of the 10 soybean FT family genes, variation types and polymorphic sites used for composing the haplotype are listed in Additional file 7: Table S7, Additional file 8: Table S8 and Additional file 9: Table S9. These results indicated that 1a-H3, 1b-H1, 1b-H6, 1b-H7, 2a-H1, 2a-H3, 2a-H4, 2a-H9, 2b-H3, 2b-H4, 2b-H6, 2b-H7, 3b-H4, 5a-H1, 5a-H2, 5a-H4 and 5b-H1 showed some association with flowering time and maturity, whereas the haplotypes of GmFT3a, GmFT4 and GmFT6 did not exhibit any apparent associations (Figs. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
Summary
Flowering time and maturity are among the most important adaptive traits in soybean (Glycine max (L.) Merill). To date, the relations between natural variations of FT family genes and the diversity of flowering time and maturity in soybean are not clear. We conducted this study to discover natural variations in FT family genes in association with flowering time and maturity. Soybeans are planted within a wide range of latitudes across the world resulting from the rich diversity of varieties in flowering time and maturity. Gai divided 256 Chinese soybean landraces into 12 maturity groups without MGX [2]. Multiple genes control flowering time and maturity in soybean. A majority of these loci were reviewed by Xia et al [17]. They play different roles in flowering and maturity maintenance under diverse photoperiod patterns. E9 has been confirmed as GmFT2a, an orthologue of the Arabidopsis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
