Influence of architectural space on the response of rice (Oryza sativa L.) to abiotic stress during germination.
The effect of space architecture on the performance of living organisms is poorly investigated. This work investigates the effect of a container shape on seed germination of rice. Seeds of rice (Oryza sativa cv. Sakha 101) were germinated under water potential (ψw) of 0, -0.205, -0.41, and -0.615 MPa, using either NaCl or PEG 6000 in wooden boxes of the same volume but with different base shape, viz. square, rectangle, pentagon, and hexagon. The Pentagon, which powered full germinability, with more uniformity and shorter lag of germination, was superior to other shapes, particularly the square which secured only 82% germinability. The differential adverse effect of osmoticum, in favor of PEG, was most evident at moderate stress (-0.410 MPa). The advantage of the Pentagon was more evident on embryo growth than on seed germination, but the reverse was true for the adverse effect of abiotic stress. The advantage of the Pentagon on embryo growth was related to improved membrane integrity and vice versa for the adverse effect of abiotic stress. Abiotic stress beyond ψw of -0.205 MPa progressively increased the thickness (the fresh weight/length ratio) of the embryo, with a greater effect on radicle than plumule and due to PEG than NaCl.