INVESTIGADORES
MARTINEZ eric Javier
artículos
Título:
BIII progeny (2n + n) from apomictic Paspalum notatum obtained through early pollination
Autor/es:
MARTÍNEZ, ERIC J.; ESPINOZA, FRANCISCO; QUARIN, CAMILO L.
Revista:
JOURNAL OF HEREDITY
Editorial:
The American Genetic Association. Oxford University Press
Referencias:
Lugar: 200 Madison Avenue, New York, NY 10016; Año: 1994 vol. 85 p. 295 - 297
ISSN:
0022-1503
Resumen:
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0cm;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";
mso-ansi-language:EN-GB;}
@page Section1
{size:595.3pt 841.9pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;
mso-header-margin:35.4pt;
mso-footer-margin:35.4pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
An apomictic tetraploid (2n = 4x = 40) cytotype of Paspalum
notatum (Bahiagrass) was emasculated and pollinated from 1 to several days
prior to anthesis (DPA). Two pollen sources were used: the tetraploid (4x)
cytotype and a diploid (2x) variety (Pensacola Bahiagrass). Spikelets
pollinated with pollen of the 4x plant at 1 DPA gave rise to only 4x seedlings,
indicating a 2n + 0 parthenogenetic origin. When pollination was
achieved 2 DPA, 46% of recovered seedlings were considered to be BIII
progenies produced through fertilization of the unreduced egg cell of an
aposporous embryo sac with a reduced sperm nucleus (2n + n = 40 +
20 = 60). Few seedlings were recovered from 3 DPA, and all were
tetraploid, originated through parthenogenesis (2n + 0). When
diploid Pensacola Bahiagrass was the pollen donor, all seedlings from 1 DPA
were parthenogenetic tetraploids (2n + 0), whereas most from 2 or 3 DPA
were BIII progenies (2n + n) and had 50 chromosomes (2n
= 40 + n = 10). Control seedlings, from pollinations at
anthesis time, were all tetraploid (2n + 0), as expected. These
results indicate that time of pollination may be manipulated in an apomictic
species to increase the production of BIII progenies. Early
pollinations, in some cases, prevent parthenogenetic development of the
unreduced egg cell in an aposporous embryo sac, allowing its fertilization.