Resumen

AVENDANO-SANCHEZ, Marselino et al. Nucleotide sequences of ITS region in S₁ and PL families of polyembryonic maize. Rev. Mex. Cienc. Agríc [online]. 2015, vol.6, n.3, pp.509-521. ISSN 2007-0934.

Polyembryony (PEm) is a rare mutation in maize (Zea mays L.) and is manifested in the formation and development of two or more plants per seed. The mechanisms and causes of PEm are not yet defined. The aim of this study was to determine the similarity of the sequence of the ITS region of mother plants and their progeny PEm obtained by self-fertilization (S₁) and open-pollinated (PL). The progeny was obtained from the UA-IMM-BAP (brachitic, high polyembryony) population. Leaf tissue samples of mothers and their progenies from 3 open-pollinated families and 3 families from S₁ lines were taken. After extracting DNA, the genomic regions ITS (Internal Transcribed Spacer) were amplified by PCR and the amplified fragments were subsequently sequenced. Comparisons of ITS sequences within each family showed some similarity but were not identical in PL2, PL4, PL5 and S5 families. However, in S3 and S7 families the comparison between the sequence of mother and its progeny (S3m vs S3P22 and S7M vs S7P22) presented 100% similarity. The similarity found between ITS sequences of mother plants and PEm descendants suggest a probable relationship between polyembryony and apomixis.

Palabras llave : Zea mays L.; ITS; nucleotide diversity; open pollinated; S₁ lines; similarity.