A sexually and vegetatively reproducible diploid seedless watermelon inducer via ClHAP2 mutation.

Seedless watermelon production relies on triploid cultivation or the application of plant growth regulators. However, challenges such as chromosomal imbalances in triploid varieties and concerns about food safety with growth regulator application impede progress. To tackle these challenges, we developed a sexually and vegetatively reproducible inducer line of diploid seedless watermelon by disrupting the double fertilization process.

Creation of a watermelon haploid inducer line via -mediated single fertilization of the central cell.

The use of doubled haploids is one of the most efficient breeding methods in modern agriculture. Irradiation of pollen grains has been shown to induce haploids in cucurbit crops, possibly because it causes preferential fertilization of the central cell over the egg cell. Disruption of the gene is known to induce single fertilization of the central cell, which can lead to the formation of haploids.

A 2.09 Mb fragment translocation on chromosome 6 causes abnormalities during meiosis and leads to less seed watermelon.

Seedlessness is a valuable agronomic trait in watermelon (Citrullus lanatus) breeding. Conventional less seed watermelons are mainly triploid, which has many disadvantages due to unbalanced genome content. Less seed watermelon can be achieved at the diploid level when certain reproductive genes are mutated or by chromosome translocation, which leads to defects during meiosis.