Efecto Xenia en maíces de normal contenido de aceite sobre el peso y la calidad de granos.

TANAKA, W.; MADDONNI, G.A

Rosario, Santa Fe

Congreso; VIII Congreso Nacional de Maíz; 2005

AIANBA

Industrial sectors that use corn seeds as a basic input, or for livestock and poultry diets, prefer high oil maize kernels because their higher oil yield and protein quality. The negative association between oil content and grain yield have motivated the production of high oil corns, based on Xenia effect (i.e. pollen effect on oil concentration). To our knowledge, information of Xenia effect stability at different post-flowering assimilate supplies is not available. The objective of the study was to analyze grain components response of (i) a maize commercial hybrid with normal oil content and (ii) the same hybrid with Xenia effect, to contrasting post-flowering source-sink ratios. The single-cross maize hybrid DK752 was self-crossed (NO, normal oil content) or crossed by a high oil concentration hybrid to produce grains with high oil concentration (HO). Pollination treatments (natural, restricted and synchronized) were performed to obtain variations of the post-flowering source-sink ratio by modifying plant grain number. The crossing did not change plant yield components. Contrarily, HO had higher grain oil concentration (ca. 93.6 mg g-1) than NO (ca. 66.2 mg g-1). Variations of final kernel weight of both NO and HO were significantly (p<0.001) related to post-flowering source-sink ratio. The highest embryo growth rate of HO, and the similar grain growth of both NO and HO, were reflected in final embryo-grain ratios (136 and 169 mg g-1, for NO and HO, respectively). Thus, variations of grain oil concentration could be partially explained by pollen effect on embryo growth. Because grain tissues (pericarp, endosperm and embryo) of both HO and NO were similarly affected by assimilate supplies (i.e. source-sink ratios) a similar embryo-grain ratio and oil concentration was recorded. Results suggest an stable Xenia effect at