Photosynthetic characteristics of hybrid and conventional rice plants as a function of plant competition

Planta Daninha

Concenço, G¹  Universidade Federal de Viçosa, Viçosa¹  Fialho, C.M.T¹  Ferreira, F.A¹  Ferreira, E.A¹  Freitas, M.A.M¹  Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Brazil¹  Galon, L¹  Schwanke, A.M.L¹  Valmont Industries, Valley, USA¹  Ricetec Corporation, Brazil¹  Aspiazú, I¹  Universidade Estadual de Montes Claros, Montes Claros¹  Silva, A.A¹  Universidade Federal do Pampa, Itaqui¹ 

关键词: competitive ability;    plant physiology;    Oryza sativa.;   

DOI  :  10.1590/S0100-83582011000400010

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

The objective of this work was to evaluate the characteristics related to the photosynthetic ability of hybrid and inbred rice varieties, as a way to assess which of the two presented higher potential to stand out under conditions of competition. The trial was set in a greenhouse in completely randomized block design and 2 x 6 factorial scheme with four replications. Factor A consisted of rice varieties (hybrid or inbred) and factor B by competition levels. Treatments consisted in maintaining one plant of either BRS Pelota (inbred) or Inov (hybrid) variety at the center of the plot, under competition with 0, 1, 2, 3, 4 or 5 plants of the variety BRS Pelota at the periphery of the experimental unit, according to the treatment. Fifty days after emergence (DAE), sub-stomatal CO2 concentration (Ci - mmol mol-1), photosynthetic rate (A - mmol m-2 s-1) and CO2 consumed (DC - mmol mol-1) were quantified, as well as shoot dry mass(SDM).Hybrid plants present higher photosynthesis capacity than inbred plants, when competing with up to 3 times its own density. When under the same competitive intensity, hybrid plants surpass the inbred. However, it should be emphasized that, when in farm condition, the lower competitive capacity with weeds often attributed to the hybrid varieties, probably is due to their lower planting density, but if weed competition is kept at low levels, hybrid rice plants may perform in the same way or usually better than inbred plants.

【 授权许可】

Unknown