Известия высших учебных заведений. Поволжский регион: Естественные науки (Jul 2021)
The regeneration potential of partenogenetic maize lines in the culture of mature embryos
Abstract
Background. Identification of varieties and lines with high morphogenetic potential is necessary for effective use of in vitro technologies in maize selection. The purpose of the study is to assess the regenerative potential of parthenogenetic maize lines during clonal micropropagation through direct organogenesis in the culture of mature embryos. Materials and methods. The objects of the study were plants of 9 homozygous lines with a hereditary predisposition to parthenogenesis: AT-3 (2n), AT-3 (4n); ATTM (bm, y, g), ATTM (bm, y, g, B-type CMS), ATTM (lg, y, wx), ATTM (lg, y, wx, B-type CMS), ATTM (bm, y, wx), ATTM (lg, y) and ATTM (bm, y). Mature embryos were used as the primary explant. Sterile culture was initiated on Murashige – Skoog (MS) medium without hormones, micropropagation was performed on MS with 0.5 and 2.0 mg/l 6-benzylaminopurine (BAP), rhizogenesis was initiated on 1/2 MS with 0.5 mg/l α-naphthylacetic acid. Results. The frequency of survival explants on sterile culture varied from 33.3 to 91.1 % in the studied lines. The AT-3 (2n) line and its tetraploid analog AT-3 (4n) differed in this parameter (p ≤ 0.01), while the lines with the same genotype and different cytoplasm did not differ. 1–2 axillaries shoots developed on explants in all lines 2 months after the start of cultivation on a medium with 0.5 mg/l BAP, while 6–7 shoots developed on a medium with 2.0 mg/l BAP. The frequency of rooted shoots varied from 48.3 to 100 % on the medium for rhizogenesis. Conclusions. The plant genotype and ploidy influenced the survival rate of explants in sterile culture and the process of rhizogenesis. The ATTM (bm, y, wx), ATTM (lg, y, wx), ATTM (lg, y, wx, B-type CMS) lines were characterized by a high regeneration potential, and the AT-3 (4n) line had a low potential. Cytoplasmic male sterility did not affect the line regeneration potentials. The number of axillary shoots on explants did not depend on the plant genotype and depend on only the BAP concentration in the medium.
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