# Identification of CtE1 gene nucleotide polymorphisms and development of SNP-based KASP markers in guar (Cyamopsis tetragonoloba (L.) Taub.)

## TL;DR

Researchers studied the CtE1 gene in guar plants to understand how genetic variations might affect flowering time, but found little impact from the gene's natural diversity.

## Contribution

The study identified five novel SNPs in the CtE1 gene and developed SNP-based KASP markers in guar.

## Key findings

- Five novel SNPs were identified in the CtE1 gene across 144 guar accessions.
- A non-synonymous SNP in the coding region caused a conservative Arg→Lys substitution.
- No significant associations were found between CtE1 SNPs and flowering time or vegetation period length.

## Abstract

Guar (Cyamopsis tetragonoloba (L.) Taub), is an important short-day legume crop, whose cultivation is limited at high latitudes due its photoperiod sensitivity, that negatively impacts flowering and maturation of this industrial-oriented crop. In its close relative, soybean, the E1 gene has been highly associated with the regulation of flowering time under long-day conditions. In this study we investigated the natural diversity of the E1 homologue gene (CtE1) in a panel of 144 guar accessions. For this purpose, the CtE1 gene was amplified and sequenced using Illumina. As a result, five novel SNPs were identified in the 5’-untranslated region, coding region, and 3’-untranslated region of the CtE1 gene. One non-synonymous SNP was located in the coding region causing a conservative Arg→Lys substitution. Based on the identified SNP, five KASP markers linked to polymorphism in the target gene were developed and tested in the guar collection. No significant associations were detected between discovered SNPs and available data on variability in flowering time or vegetation period length in the cohort of 144 accessions. These findings suggest that natural variation of the CtE1 gene in the studied germplasm collection has minimal effect on flowering or maturation. The limited functional allelic diversity observed in the CtE1 gene of guar compared to the E1 gene in soybean likely reflects differences in their evolutionary histories, domestication bottlenecks, and selection pressures.