Abstract
Cucumis melo ssp. agrestis is a vital crop in the Cucurbitaceae family. Traditional breeding has been the primary method, but prolonged artificial selection has led to a gradual decline in the genetic diversity of thin-skinned sweet melon. An efficient induction system for thin-skinned sweet melon haploids has been established to innovate germplasm resources. Initially, unfertilized ovules treated with low temperature are peeled and inoculated onto the callus induction medium (CIM) for 2 days of dark culture, followed by 30 days of culture under subdued light to induce callus formation. Subsequently, the callus tissue is transferred to a proliferation medium (PM) and cultured under intense light until green cells and bud differentiation occur. Finally, rooting induction medium (RIM) induces rooting to form complete plants. Through validation with eight genotypes of disease-resistant thin-skinned sweet melon, this method exhibits a haploid induction rate of 12.26%, a diploid induction rate of 54.72%, and a tetraploid induction rate of 33.02%. Incorporating molecular marker-assisted breeding techniques, we have developed usable plants resistant to powdery mildew, downy mildew, and frost mold.