Clonal Reproduction through Seeds in Sight for Crops. Issue 3 (March 2020)

• Record Type: Journal Article
• Authors: Ozias-Akins, Peggy; Conner, Joann A.
• Is Part Of: Trends in genetics. Volume 36:Issue 3(2020)
• Page Start: 215
• Page End: 226
• Publication Date: 2020-03
• Subjects: apomeiosis -- apomixis -- clonal reproduction -- genome elimination -- hybrid vigor -- parthenogenesis; Genetics -- Periodicals; 576.5
• DOI: 10.1016/j.tig.2019.12.006
• Languages: English
• ISSNs: 0168-9525

Abstract

Abstract : Apomixis or asexual reproduction through seeds, enables the preservation of hybrid vigor. Hybrids are heterozygous and segregate for genotype and phenotype upon sexual reproduction. While apomixis, that is, clonal reproduction, is intuitively antithetical to diversity, it is rarely obligate and actually provides a mechanism to recover and maintain superior hybrid gene combinations for which sexual reproduction would reveal deleterious alleles in less fit genotypes. Apomixis, widespread across flowering plant orders, does not occur in major crop species, yet its introduction could add a valuable tool to the breeder's toolbox. In the past decade, discovery of genetic mechanisms regulating meiosis, embryo and endosperm development have facilitated proof-of-concept for the synthesis of apomixis, bringing apomictic crops closer to reality. Highlights: The study of natural apomicts, dispersed over multiple plant orders, has demonstrated that alterations of different genes within reproductive pathways can lead to the emergence of apomixis. Research on natural apomicts, as exemplified with the characterization of the parthenogenesis-inducing ASGR-BBML gene, will yield tools to engineer the trait in multiple crop species. Pyramiding multiple components of the asexual reproductive pathway has been successful to create apomictic offspring in the model plants Arabidopsis and rice, albeit at lower penetrance than required for deployment in agriculture. The creation of apomictic agricultural crop species would greatly facilitate crop yield and vigor due to maintenance of heterosis over multiple generations.