Variability of Rice Haploids Obtained From In Vitro Anther Culture

Abstract

Morphological variability of haploid plants and doubled haploids of rice obtained from one callus line in in vitro anther culture has been studied. The study was performed on rice (Oryza sativa L. subsp. japonica Kato) plants of the Kaskad varietу. Regenerants of the same callus line derived from one rice anther (four lines in total) were divided into 2–3 groups of 20–30 plants (depending on the sample size) in the order of their differentiation on a callus and transplantation on the rooting medium. Two callus lines (15.1 and 18.1) generated both haploids and doubled haploids (in equal proportion), while two other callus lines (5.1 and 7.2) formed numerous haploids. In the case of the 5.1 and 7.2 lines, regenerants with a larger ordinal number were characterized by decreased size indices of derived plants (plant height, number of flowers on the main panicle, and the number of panicles). No statistically significant difference has been revealed between the haploids and doubled haploids originating from the 15.1 and 18.1 lines. To induce the doubling of a chromosome number in haploid regenerants by colchicine or other antitubulin compounds, it is recommended to use the earliest plants developing on a callus. Using the Hotelling’s T2 criterion calculated for the whole complex of biometric indices, a statistically significant (p = 0.001) difference was revealed between haploids of four callus lines and doubled haploids of two callus lines. Haploids of different lines differed by 3–4 traits, while doubled haploids differed by three of five traits (panicle length, productive tilling capacity, and plant height). Rice varieties interesting for breeders may be improved using in vitro anther cultures.