Abstract: The present paper studied the effect of starch metabolism on the determination of morphogenetic pathway of plant cells in vitro. In the cells of tobacco calli, the average value of starch amount during regenerating was 8.22 times as much as that of subcultures, and the amylase activities during regenerating was 4.48 times higher than that of subcultures. In regenerating calluses of carrot, the starch amount was 0.95 times more and the amylase activities were 1.13 times higher than that of subcultures. During regeneration, the average value of starch amount and amylase activities of tobacco were 6.37 times more and 6.14 times higher than that of carrot, but were 0.74 times and 1.55 times during subculture, respectively. Moreover, starch grains of tobacco cells accumulated in single, stained by I2-KI into blue or dark blue;but in carrot cells, 2-4 or more starch grains aggregated in one plastid, and stained into red to violet. The relationship of morphogenetic pathway determination of plant cells in vitro and the level of starch metabolism, structure features and accumulation pattern of starch grains was discussed.

Key words: Nicotiana tabacum L, Daucus carota L, Starch metabolism, Morphogenetic pathway in vitro