Phenotypic and Genetic Stability Evaluation of the Targeted GA20ox-2 Gene Mutation in CRISPR/Cas9 Mutant Rice Derived from Mentong Cultivar
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Date
2022-01-19
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Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumber Daya Genetik Pertanian
Abstract
Abstract. Lodging is a major constraint in cereal crops which lead to reduction of yield and grain quality. Therefore, lodging tolerant varieties have led to remarkable harvest index increases in cereal crops. Gibberellin (GA) is important endogenous hormones responsible to plant height trait and its deficiency in plants may cause dwarfism. In this study, a set of semidwarf F3 mutant rice population generated from a cross between Mentong, an Indonesian local swamp rice cultivar (female parent exhibits tall plant height), and K-15, a CRISPR/Cas9-target mutant of GA20ox-2 in Kitaake (donor parent), was subjected to assessment for their phenotypic and genotypic stability. A total of 19 mutant rice lines along with parents were planted in the greenhouse and some important agronomic traits (plant height, tiller number, and heading date) were observed to assess stability of the phenotype. The genetic or hereditary stability of the mutated sites
on GA20ox-2 gene was further confirmed by sequence comparison between targeted gene in mutant rice lines and their parents. Based on phenotype observation, all lines generally showed reduction in plant height (20.6–53.8%) compared to
their female parent and had more tiller number (14.33–26.50) compared to their parents. Of these, three lines were phenotypically homogeneous, and were molecularly confirmed conferring the allele of the GA20ox-2 which were homozygous. Our findings suggest that development of mutant rice using genome editing technology approach combined with conventional breeding would be useful to facilitate rapid and precise crop improvement in plant breeding program.
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Breeding, rice, genetic