Abstract: The embryos derived from intergeneric crosses between Triticum aestivum L. (2n = 6x= 42) and Zea mays L. (2n= 20), Tripsacum dactyloides L. (2n= 4x= 72), as results of the elimination of paternal chromosome and having no endosperm as normal, are difficult to develop completely in vivo. Hormonal analyses in such intergeneric hybridized ovaries have been carried out including indole-3-acetic acid (IAA), zeatin (Z) and zeatin riboside (ZR), and abscisic acid (ABA) during different developmental stages of embryo. The results indicated that IAA level in hybridized ovaries was much lower than that in self-pollinated ovaries. Moreover, the active changes of Z+ZR and ABA contents were also different between the above two types of ovary. Nevertheless, the ratio changes of IAA/(Z+ZR) and IAA/ABA were similar between the two types of ovary, the same was true in the ratio changs of IAA, Z+ZR, and ABA to the sum of these three types of endogenous hormones. But the three types of ratios in hybridized ovaries were varied far more greater than those in self-pollinated ones. It suggested the importance to maintain dynamic equilibrium of multiple hormones and sequential regulation during the embryo development. That the distantly hybridized embryos failed to mature successfully was probably associated with a deviation from the normal changes of endogenous hormones levels and balance system of multiple hormones in addition to the lack of endosperm nourishment.

Key words: Wheat: Maize, Tripsacum dactyloides, Endogenous phytohormone