Volume 11, Issue 1, Pages 222-225 (January 2018) A 2.833-kb Insertion in BnFLC.A2 and Its Homeologous Exchange with BnFLC.C2 during Breeding Selection Generated Early-Flowering Rapeseed  Lei Chen, Faming Dong, Jing Cai, Qiang Xin, Caochuang Fang, Liang Liu, Lili Wan, Guangsheng Yang, Dengfeng Hong  Molecular Plant  Volume 11, Issue 1, Pages 222-225 (January 2018) DOI: 10.1016/j.molp.2017.09.020 Copyright © 2017 The Author Terms and Conditions

Figure 1 Cloning and Functional Analysis of the Flowering Time Genes BnFLC.A2 and BnFLC.C2 in Rapeseed. (A) Plant morphologies of the early-flowering NIL L06 (the recipient), the late-flowering NIL L04, and typical positive (T1+) and negative (T1-) plants derived from a transgenic T0 plant carrying a single copy of PFGC5941-L04-BnFLC.A2. Scale bar, 10 cm. (B) DTF distribution of L06 (1, red), L04 (2, green), and four T1 families (BnA2-2, BnA2-10, BnA2-14, and BnA2-37) carrying a single copy of transgenic PFGC5941-L04-BnFLC.A2. The numbers 3 and 4, 5 and 6, 7 and 8, and 9 and 10 on the horizontal axis represent the transgenic-negative (red) and -positive (green) plants from BnA2-2, BnA2-10, BnA2-14, and BnA2-37, respectively. DTF of each plant as reflected by a red or green dot is indicated on the vertical axis. The family DTF is expressed as mean ± SEM. ***P < 0.0001. (C) Plant morphologies of the early-flowering NIL R11 (the recipient), the late-flowering NIL R15, a typical positive T1 plant derived from a transgenic T0 plant carrying multiple copies of PFGC5941-R15-BnFLC.C2, and an R11-null plant. Scale bar, 10 cm. (D) DTF of R11-null (1), R11 (2), R15 (3), and five T1 families carrying multiple copies of transgenic PFGC5941-R15-BnFLC.C2, i.e., BnC2-2 (4), BnC2-13 (5), BnC2-19 (6), BnC2-28 (7), and BnC2-29 (8). DTF of each plant as reflected by a red or green dot is indicated on the vertical axis. The family DTF is expressed as mean ± SEM. For each transgenic-positive family, the average DTF is compared with R11-null. ***P < 0.0001. (E) Genomic structure of BnFLC.A2, Bnflc.a2, and BnFLC.C2. The red arrows/arrowheads indicate exons. The spaces on the thick black lines indicate the sequence variations between BnFLC.A2 and Bnflc.a2. The 2.833-kb fragment insertion in the first intron is indicated by a black box. The lines carrying a specific allele are listed in parentheses following the corresponding allele. (F–M) Gene expression levels under natural winter and spring conditions, respectively. qPCR analysis of BnFLC.A2 (F and J), BnFLC.C2 (G and K), the BnFT family (H and L), and the BnSOC1 family (I and M) in the third leaves from the top of a plant was performed. The numbers under the horizontal axis indicate the sampling time (days) after sowing. The alternation of seasons (or seasons) during the sampling date is marked at the bottom. DTF for each line in (F and G) is indicated by black arrows, but not indicated in (L and M) because only DTF of L06 is available at the last sampling date. Expression values are means ± SEM based on three biological replicates. (N) Segmental HEs between chromosomes A2 and C2 as reveled based on sequence read coverage analysis. Coverage depth (vertical axis) obtained for chromosomes A2 and C2, respectively, was calculated by mapping the Illumina resequencing reads from L04, L06, R15, and R11 (named on the left) to the reference genome of B. napus Darmor-bzh. The height of each line (a 10-kb window) from the horizontal axis represents the coverage depth. A duplication event is indicated in red, while a deletion event is indicated in blue. Sizes of chromosomes on the horizontal axis are indicated in Mb. Black arrows indicate the physical positions of BnFLC.A2 and BnFLC.C2; their rough physical positions are shown in parentheses. (O) Comparisons of the mean DTF of accessions carrying a specific genotype combination on the BnFLC.A2 and BnFLC.C2 loci in eight environments. E1–E8 represent the eight experimental environments, i.e., Wuhan-2013, Changsha-2013, Nanjing-2013, Ezhou-2013, Chongqing-2013, Wuhan-2014, Changsha-2014, and Nanjing-2014. DTF values are expressed as means ± SEM. The number of accessions for a given genotype combination is listed in parentheses. Molecular Plant 2018 11, 222-225DOI: (10.1016/j.molp.2017.09.020) Copyright © 2017 The Author Terms and Conditions