Utilization of Satsuma mandarin male sterility by cell engineering for citrus seedless breeding

Citrus is the most important fruit crop globally and in southern China.
Cell engineering holds great potential for citrus genetic improvement.
In our citrus breeding program, somatic hybrids were produced from more than 50 interspecific and intergeneric fusion combinations which efficiently circumvented the reproductive barriers such as nucellar polyembryony and male/female sterility commonly encountered in citrus conventional breeding.
Numerous natural tetraploids (doubled diploids) from more than 70 poly- and mono-embryonic citrus genotypes and species were exploited or induced.
Thousands of triploid plants were then recovered from over 100 interploid crosses by using elite tetraploids as pollen parents, and several triploid seedless cultivars were released.
Facilitated by molecular marker analysis of numerous citrus somatic hybrids and cybrids, a strategy of male sterile cybrid production by symmetric fusion between embryogenic callus protoplasts of Satsuma mandarin (cytoplasmic male sterility, CMS type) and mesophyll protoplasts of elite seedy cultivars were put forward, and diploid cybrid plants containing sterile cytoplasm from Satsuma mandarin were regenerated.
Some cybrids, already showing male sterile and seedless traits, were released as new cultivars and further used as mono-embryonic core seed parents to cross with other seedy cultivars in effort to produce more cybrid hybrid progenies for potential seedlessness.
Cell engineering approaches combined with application of molecular markers and multi-omics technology greatly enhanced the efficiency of targeted citrus seedless breeding.

XV International Citrus Congress

Wen-Wu Guo, Rong Wang, Xiao-Meng Wu, Kai-Dong Xie, Xiu-Xin Deng

citrus, male sterility, somatic cybridization, fruit seedlessness, genetic improvement

https://doi.org/10.17660/ActaHortic.2026.1448.32