**2.3 The types of embryo sacs appeared in apomictic plants**

Ten types of embryo sacs were observed and most of the embryo sacs belonged to PS type (**Table 1**, [36]). In apomicts, most ovules showed the number of embryo sacs more than one. And the ovules with different embryo sacs (5PS to 2PS, PS +PNn to 4PS +PNn, S, PNn) were observed. The percentage of S type (*Polygonum* type) was 13.6% (8/59), 9.1% (3/33), 12.9% (4/31) and 5.4% (2/37) in competitor, Nanou, Tifton and Common, respectively. PNn type (*Panicum* type) was only observed in one ovule among the tested varieties.

Among the 4 varieties, the frequencies of PN type were from 5.0% to 30.3%, and that of PS type were from 60.7% to 90.0%. Total frequencies of apospory were 86.4%, 91.1%, 87.1% and 95.0% in competitor, Nanou, Tifton and Common, respectively.
