Formation of Rice Tetraploids in In Vitro Androgenesis

Abstract

Creating tetraploid rice is a promising field in increasing crop yields. There are currently no commercial rice varieties due to poor panicle grazing, which is caused by low pollen fertility. It is stated in the scientific literature that tetraploid plants are obtained in vitro androgenesis as an additional starting material. The aim of the study was to study the characteristics of callus in anther culture of rice in vitro, on which tetraploid plants are formed, and the characteristics of rice tetraploid regenerants. Studies were performed on 15 F2 hybrids of Oryza sativa L. subsp. japonica Kato of three hybrid combinations. In vitro androgenesis is a reliable way to obtain polyploid regenerants in the majority of genotypes: 59 plants (1.9% of all green regenerants) are tetraploid. The proportion of calli with tetraploids is 17.6%. Calli on which tetraploid plants were formed are characterized by a decreased number of haploids and an increased number of seedless plants of nonhaploid origin. The maximum number of tetraploids per callus aggregate is 12 pcs. Tetraploids obtained in vitro androgenesis have a slight grazing of the main panicle (on average 1.0–6.0 pcs.), which is typical for polyploid rice.