Natural Variation Of GmCOL Family Genes In Soybean Varieties Covering A Wide Range Of Maturity Groups

Proper timing of flowering,and maturity of crops are ecologically,and agronomically significant traits to determine adaptation,reproduction,seed quality,and yield for soybean under changing environment conditions.Natural variations are the main resource for evolutionary changes for the adaptive potential of a species.Most of the natural variations are quantitative,and determined by molecular polymorphisms at multiple loci,and genes.In the photoperiod regulation of flowering,and reproduction progresses in plants,CONSTANS(CO)a BBX family member,and the central regulatory gene,trigger the production of mobile florigen FT(Flowering Locus T),and is responsible for flowering initiation.CONSTANS-LIKE genes functioned not only in flowering,but also other important physiological processes in soybean.However,now it is not clear about the relation between natural variations of COL family genes,and flowering time,and maturity in soybean.One hundred and twenty-eight soybean varieties covering 14 maturity groups from MG0000 to MGX were selected as experimental materials.These varieties were planted under normal day in Beijing,China,and the developmental stages(VE,R1 and R8)were recorded.As expected,these accessions varied greatly in phenotypic traits of flowering time,and maturity dates.According to the genotype,and the structure of the growth periods,the varieties were divided into three groups of MG0000-MG0,MGI-MGV,and MGVI-MGX.In flowering time(VE-R1),maturity groups of MG0000,MGIX+X,and MGVII showed significant differences concerning flowering time dates while,in maturation(VE-R7)period all maturity groups were significantly different regarding maturity dates except maturity group MG00.In this study,82 soybean accessions were used to recognize the determinacy behavior i.e.indeterminate and determinate traits,and 58 cultivars were indeterminate,and 24 cultivars were determinate.This endeavor enabled the confirmation,and identification for important agronomic traits of soybean for North America,and Chinese-Russian cultivars.This study will be helpful for future soybean cultivar breeding.Among the 28 COL family genes in soybean reference genome(Williams 82),21 were then cloned,and sequenced,and the sequence polymorphisms were analyzed which had remarkable diversity in COL sequence polymorphism levels.The growth periods of tested soybean varieties were greatly different,and the MGI-MGV varieties showed strong correlation between flowering time,and maturity.8 genes(GmCOL1/3/4/8/13/15/16/19)showed close relationship with early flowering,and maturation in comprising dominant genotypes,and 11 genes(GmCOL2/5/6/14/20/22/23/24/25/26/28)expressed divergence physiognomy for flowering,and maturation.In some cases,recessive genotypes showed early flowering,except for GmCOL9 and GmCOL10.The use of genotypic identification and prediction of growth period(VE-R1)information for variety screening can increase breeding efficiency.In 21 soybean GmCOL family genes,it has been revealed that some natural variations exist in association with flowering and maturity dates and may involve soybean adaptability in different environments.As far as the whole genomic region,GmCOL1 and GmCOL3 was highly conserved.The remaining 19 genes showed genetic variations which brought about,by mutation,viz.some SNPs and Indels;Moreover,a few genes showed some strong linkage disequilibrium.The rest of GmCOL 19 genes showed some point mutations,can lead to changes in the structure of an encoded protein or to a decrease or complete loss in its expression.To further understand their roles in flowering date and maturity,it needs to identify these natural variations from the transcriptional profiles and genetically modified functional verification.Analyzing the GmCOL genes haplotypes,found that some haplotypes of GmCOL5-Hap2,GmCOL13-Hap2/3,GmCOL28-Hap2 showed correlative associations with flowering dates and maturity.The 21 GmCOL family genes expressed some natural variations,which may involve soybean adaptation to different environments,and have an influence on diverse flowering dates and maturity.This work will help to ascertain the relationship between the key phenotypic traits(viz.DTF,DTM,PH)of the cultivars and GmCOL gene family and will provide a theoretical basis for the molecular design of soybean growth traits.