Seed Germination Research Paper

a) Seed Germination and Seed Emergence

Germination is the process that starts with the uptake of water by the dormant dry seed and terminates with the emergence of the radicle. At this stage, intense metabolic activity will change that involve metabolic activity and cell elongation process (Bewlwy, 2001). Seed germination occurs when the sufficient water had been absorbed so that the seed coat will become soft and elastic. The coleorhiza (the sheath covering the radicle or embryonic primary root) will slightly elongate, emerging through the seed coat and the radicle breaks through the coleorhiza and becomes anchored in the soil. Under low oxygen, the coleoptile may emerge before the root. This process occurs within two days at the temperature between 10°C until 41°C. Seminal roots form when the coleoptile continues to elongate and several lateral roots grow (Moldenhauer & Slaton, 2001).

Seed emergence occurs when the first internode called mesocotyl has elongated and pushed the tip of the rice coleoptile through the soil surface. For some cultivar, this mesocotyl length may be differing.

One of them is mutation that was induced in MR219 using gamma rays at 300 Gy. This induction was done to generate the superior genotype for minimum water requirement for paddy rice plant. This experiment was conduct under water stress simulated non-flooded water under glasshouse and field conditions. Only 12 potential lines with adaptive traits at M4 generation were selected after this experiment. But, only two potential lines which are MR219-4 and MR219-9 were selected. Based on these two lines, only mutant MR219-9 show unique characteristics which can perform well under saturated conditions in irrigated areas and in aerobic condition under dry land system. Other than that, these two mutants also can tolerate well in flood-prone rain areas (Rusli Ibrahim, Abdul Rahim Harun & Zaiton Ahmad,