QTL identification of flowering time at three different latitudes reveals homeologous genomic regions that control flowering in soybean

Abstract

Since the genetic control of flowering time is very important in photoperiod-sensitive soybean (Glycine max (L.) Merr.), genes affecting flowering under different environment conditions have been identified and described. The objectives were to identify quantitative trait loci (QTLs) for flowering time in different latitudinal and climatic regions, and to understand how chromosomal rearrangement and genome organization contribute to flowering time in soybean. Recombinant inbred lines from a cross between late-flowering 'Jinpumkong 2' and early-flowering 'SS2-2' were used to evaluate the phenotypic data for days to flowering (DF) collected from Kamphaeng Saen, Thailand (14°01'N), Suwon, Korea (37°15'N), and Longjing, China (42°46'N). A weakly positive phenotypic correlation (r = 0.36) was found between DF in Korea and Thailand; however, a strong correlation (r = 0.74) was shown between Korea and China. After 178 simple sequence repeat (SSR) markers were placed on a genetic map spanning 2,551.7 cM, four independent DF QTLs were identified on different chromosomes (Chrs). Among them, three QTLs on Chrs 9, 13 and 16 were either Thailand- or Korea-specific. The DF QTL on Chr 6 was identified in both Korea and China, suggesting it is less environment-sensitive. Comparative analysis of four DF QTL regions revealed a syntenic relationship between two QTLs on Chrs 6 and 13. All five duplicated gene pairs clustered in the homeologous genomic regions were found to be involved in the flowering. Identification and comparative analysis of multiple DF QTLs from different environments will facilitate the significant improvement in soybean breeding programs with respect to control of flowering time.

Molecular characterization and genetic diversity analysis of soybean (Glycine max (L.) Merr.) germplasm accessions in India

“…Two of the SSR markers amplifying unique alleles were known to be linked with two different phenotypic traits. The Satt055 was reported to be linked with photoinsensitivity trait (Liu et al 2011). The Satt055 had amplified a unique allele in accessions EC333915.…”

Inheritance of late flowering in natural variants of soybean cultivars under short-day conditions

“…The monthly mean air temperature from emergence to (Cober, 2011). Liu et al (2011) reported that in a tropical location, such as Thailand, planting starts in November because flowering time is affected by warmer temperature rather than by the photoperiod; therefore, the high temperature during the night has a more significant effect on the induction of flowering.…”

QTL Study to Reveal Soybean Response on Abiotic and Biotic Stresses

“…A flowering QTL in the Satt202-Satt371 (Chr 6) was for both Korea and China. The environmentally less sensitive QTL with higher phenotypic variation and maximum additive affect in China was shown than that in Korea (Liu et al, 2011). Different photoperiod and temperature on these two environments may contribute mainly for the distinctive flowering variations.…”

“…QTLs associated with complex abiotic and biotic stresses tolerance traits have been targeted and elucidated their relations with other traits by several approaches (www.phytozome.net/soybean; http://soybase.org). A number of QTLs for abiotic and biotic stresses as well as flowering/maturity have been identified using several populations across environments (Abdel-Haleem et al, 2012;Cheng et al, 2011;Hamwieh et al, 2011;Liu et al, 2011;Xing et al, 2012).…”

“…To investigate how soybean responds to different environmental conditions (Table 1), recombinant inbred lines (RILs) from a cross between late-flowering "Jinpumkong 2" and early-flowering "SS2-2" were used for the QTL analysis for flowering time at different latitudes (Table 2). Phenotypic evaluations for days to flowering were conducted at two areas with different latitudes, Suwon, South Korea (37 o 15'N) and Longjing,China (42 o 46'N), and a strong correlation of days to flowering was observed between Korea and China (Liu et al, 2011).…”