The determinate growth habit of plants reduces the number of internodes and shortens the main stem by terminating the shoot apical meristem through a transition to inflorescence. Understanding the genetic basis of this habit can help optimize crop yield and cultivation technology for vegetable breeding.
This study aimed to identify the determinate-2 (de-2) gene responsible for the determinate growth habit in the W-sk cucumber line. Termination of the main stem in the W-sk line occurred between 14 and 23 internodes, depending on cultivation conditions. Resequencing of the W-sk genome identified a novel SNP in the cucumber TERMINAL FLOWER1 (CsTFL1) gene, explaining the de-2 phenotype.
This was verified with a CAPS-T marker cosegregation with determinate growth in the F2:3 population, and this polymorphism is unique among genotyped indeterminate cucumber cultivars or breeding lines. Crossing the W-sk line with the G421 line with the determinate (de) gene confirmed the allelism of both genes. An SNP in CsTFL1 in the W-sk line introduced a premature stop codon, resulting in the putative deletion of 13 amino acids, possibly causing a determinate growth habit. Overall, this study provides insights into the genetic basis of cucumber plant growth architecture and advances in cucumber breeding.
Biernacik, B., Słomnicka, R., Kaźmińska, K., Mużacz, S., & Bartoszewski, G. (2024). A single nucleotide substitution introducing premature stop codon within CsTFL1 explains the determinate-2 phenotype in cucumber (Cucumis sativus L.). Scientific Reports, 14(1), 1-11. https://doi.org/10.1038/s41598-024-76549-w
Source: Nature.com