AOBPreview originally published online on May 29, 2009
Annals of Botany 2009 104(2):325-334; doi:10.1093/aob/mcp127
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pollen source effects on growth of kernel structures and embryo chemical compounds in maize
1 Departamento de Producción Vegetal
2 Departamento de Recursos Naturales y Ambiente, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, Ciudad de Buenos Aires (C1417DSE), Argentina
* For correspondence. E-mail wtanaka{at}agro.uba.ar
Received: 17 December 2008 Returned for revision: 23 January 2009 Accepted: 14 April 2009 Published electronically: 29 May 2009
Background and Aims: Previous studies have reported effects of pollen source on the oil concentration of maize (Zea mays) kernels through modifications to both the embryo/kernel ratio and embryo oil concentration. The present study expands upon previous analyses by addressing pollen source effects on the growth of kernel structures (i.e. pericarp, endosperm and embryo), allocation of embryo chemical constituents (i.e. oil, protein, starch and soluble sugars), and the anatomy and histology of the embryos.
Methods: Maize kernels with different oil concentration were obtained from pollinations with two parental genotypes of contrasting oil concentration. The dynamics of the growth of kernel structures and allocation of embryo chemical constituents were analysed during the post-flowering period. Mature kernels were dissected to study the anatomy (embryonic axis and scutellum) and histology [cell number and cell size of the scutellums, presence of sub-cellular structures in scutellum tissue (starch granules, oil and protein bodies)] of the embryos.
Key Results: Plants of all crosses exhibited a similar kernel number and kernel weight. Pollen source modified neither the growth period of kernel structures, nor pericarp growth rate. By contrast, pollen source determined a trade-off between embryo and endosperm growth rates, which impacted on the embryo/kernel ratio of mature kernels. Modifications to the embryo size were mediated by scutellum cell number. Pollen source also affected (P < 0·01) allocation of embryo chemical compounds. Negative correlations among embryo oil concentration and those of starch (r = 0·98, P < 0·01) and soluble sugars (r = 0·95, P < 0·05) were found. Coincidently, embryos with low oil concentration had an increased (P < 0·05–0·10) scutellum cell area occupied by starch granules and fewer oil bodies.
Conclusions: The effects of pollen source on both embryo/kernel ratio and allocation of embryo chemicals seems to be related to the early established sink strength (i.e. sink size and sink activity) of the embryos.
Key words: Zea mays, maize, pollen, kernel, embryo, endosperm, oil, protein, starch, soluble sugars
CiteULike 
Connotea 
Del.icio.us What's this?
Related articles in Ann Bot:
- ContentSnapshots
Ann Bot 2009 104: i.[Extract] [Full Text]
This article has been cited by other articles:
|
|
 |
|
  W. Tanaka and G. A. Maddonni Maize Kernel Oil and Episodes of Shading during the Grain-Filling Period Crop Sci., October 22, 2009; 49(6): 2187 - 2197. [Abstract] [Full Text] [PDF]
|
|