MOLECULAR ANALYSIS OF WAXY GENE MARKERS IN SORGHUM CROSSES KD4 AND BONTEB GUNUNGKIDUL

Abstrak

HIGHLIGHTS- Local sorghum crosses show unique fixation of the waxy starch gene allele- Only Wxc allele is expressed, while other waxy alleles are not detected- Waxy allele expression strongly relates to low amylose grain quality- Marker-based selection supports breeding of soft-textured sorghum- Findings enhance sorghum use for food, feed, and industrial applicationsABSTRACTSorghum (Sorghum bicolor L.) is a food crop exhibiting resilience to extreme environmental conditions and potential to develop as an alternative food source. Quality of sorghum seeds is significantly influenced by starch composition in endosperm regulated by waxy (Wx) gene. This gene has several major alleles: Wxa, Wxb, and Wxc, playing roles in amylopectin and amylose syntheses. The purpose of study is to analyze the expression of Wx alleles in the crossbreeding of sorghum cultivars KD4 and Bonteb Gunungkidul. Main method used was molecular marker-based PCR method. Leaf and seed samples of sorghum were collected and extracted using the CTAB method to obtain high-quality genomic DNA. PCR reactions were performed with specific primers for each allele, and the amplification results were analyzed through 1.5% agarose gel electrophoresis. Statistical analysis was performed to ensure result significance through: Chi-Square Test to determine relationships between waxy allele expression with genetic segregation within cross populations, Allele Frequency Analysis to determine distribution of waxy genotypes within populations by comparing counts showing expressions of Wxa, Wxb, and Wxc, and Pearson Correlation Test to evaluate relationships between waxy gene expression with specific agronomic traits (e.g., amylose content). Main findings showed that only Wxc allele did exhibit a clear amplification band, while Wxa and Wxb did not show significant expression. Further studies are needed to understand the regulation of Wx gene expression and its potential implications to molecular selection, ultimately enhancing sorghum quality for both food and industrial applications.