Histological studies on the relationship between the low seed set and abnormal embryo sacs in sweet potato, <i>Ipomoea batatas</i> (L.) Lam.

This study aimed to investigate the relationship between low seed set and abnormal embryo sacs lacking normal female organs, such as one egg cell, two assistant cells, polar nuclei, in Ipomoea trifida, which is closely related sweet potato, potato cultivars lines, through histological analysis of their ovaries on flowering day. Ovaries diploid, tetraploid, hexaploid lines I. trifida each had four ovules, except for some with five or six ovules. Almost all ovules per ovary, although sib-cross three The number ovary did not have direct effects set. frequency sac increased polyploidy ‍trifida. However, it varied among different lines. Moreover, variation occurred at an earlier stage gametogenesis (type A) tetraploid plants These findings suggest that high a primary cause decline propagation occurs evolution process potato.