IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Determination of maximum achene size in sunflower
Autor/es:
A. MANTESE, D. RONDANINI, D. MEDAN, A.J. HALL
Lugar:
Córdoba, España
Reunión:
Congreso; 17th International Sunflower Conference; 2008
Institución organizadora:
International Sunflower Association
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";}
p.MsoBodyText2, li.MsoBodyText2, div.MsoBodyText2
{margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
mso-pagination:widow-orphan;
font-size:12.0pt;
mso-bidi-font-size:10.0pt;
font-family:Arial;
mso-fareast-font-family:"Times New Roman";
mso-bidi-font-family:"Times New Roman";
mso-ansi-language:ES-TRAD;}
@page Section1
{size:612.0pt 792.0pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
It has been suggested that the
maximum volume of grain could determine its potential dry weight, and that
grain water content can be used as a surrogate of grain volume, but this issue
has not been investigated in sunflower. The aim of this work was to examine the
relationships between final achene weight and the dynamics of achene volume and
achene, pericarp and embryo water contents. Seven experiments were conducted
between 2002-6 in Argentina,
testing a total of 10 sunflower genotypes. Achenes were collected every 2-3
days, and the fresh and dry weights of the achene, pericarp and embryo, achene
dimensions (length, breadth, width) and volume were determined. The pericarp
played a dominant role in achene water content throughout grain filling. Maximum
achene and pericarp water contents were reached early in development, and these
maxima were good predictors of final achene and embryo dry weights across
genotypes. Achene water content and volume showed parallel increases between
anthesis and peak achene water content, but achene volume and dimensions
continued to increase for a few days after the time of peak achene water
content. We have concluded that the relationship between final achene dry
weight and peak values for achene water content is not causal, and that the
strong correlation between these variables arises because of the correlation
between achene water content and volume during the phase where both variables
increase together and the fact that, at the time of peak achene water content,
the achene has reached close to 90% of its final volume.
Key words: sunflower- achene size- water content- pericarp- achene dimensions.