Abstract:

The starch variation of normal and abnormal embryo systems during the embryonic selection in Cunninghamia lanceolata is carried out in the normal seeds, starch grains are always present in the active growth areas and their adjacent cells. There are two cases in the formation of the abnormal seeds:1. The abortion of the embryos. No starch grains exist in the embryos and suspensor cells. In the female gametophytes, starch grains are present or absent. 2. The abortion of the female gametophytes. At the beginning the embryo systems are well-developed and the distribution of starch frains is the same as that of the normal embryos-a layer of starch grains are accumulated in the cells of the female gametophyte around the embryos and the outer cells crinkle towards the centre while the crinkled areas enlarge starch grains diminish. At last, the female gametophytes die and embryos systems degenerate.The former case could be the result of the inbreeding depressions, the latter case maybe the reason that causes the formation of the aborted seeds.

Key words: Cunninghamia laceolata, Embryonic selection, Starch variation, Embryo abortion