ESTUDIO CITOGENÉTICO DELMAÍZHÍBRIDO SIMPLEH-311 (ZEAMAYSSSP. MAYS), TEOCINTLE CHALQUEÑO (ZEAMAYS SSP. MEXICANA)YSUHÍBRIDO F1 (ZEA MAYS SSP . MAYS X ZEA MAYS SSP. MEXICANA)

Abstract

Meiotic prophase and metaphase I chiasma
frequency was analyzed in cells of maize
hybrid simple H-311 (Zea mays ssp. mays),
teosintle chalqueño (Zea mays ssp. mexicana) and their resulting hybrid F1(Zea mays
ssp. mays X Zea mays ssp. mexicana).
Chiasma frequency was smaller in F1 than in
its progenitors. Mean total chiasms per cell
was 21.88 in maize hybrid simple H-311,
21.31 in teosintle chalqueño and 16.63 in
the F1.

In the hybrids, the crossing between
homologous chromosomes was irregular,
presenting univalents, trivalents, tetravalents,
pentavalents and hexavalents. All three plant
types presented a diploid chromosome
number of 2n = 20. The mean total length per
genome was 33.51 µm in maize hybridsimple
H-311, 33.18 µm in teosintle chalqueño and
33.33 µm in the F1. The total length of the
chromosomesofall threegenomes wassimilar,
with a length between 2 and 5 µm. The three
karyotypes constituted of metacentric and
submetacentric chromosomes. Maize hybrid
simple H-311 and teosintle chalqueño
presented a close phylogenetic relationship,
as they had the same chromosome number
and similar relationships and lengthsbetween
chromosome arms. Moreover, the hybrid F1
genome presents chromosome pairing and
genetic exchange between chromosomes of
both plants