, Volume 24, Issue 1, pp 197–208

Evolutionary autoploidy in the sweet potato (Ipomoea batatas (L.) Lam.) and its progenitors


  • Ichizo Nishiyama
    • Department of AgricultureMeijo University
  • Tsukasa Miyazaki
    • Kyushu Agricultural Experiment Station
  • Satoshi Sakamoto
    • Kyushu Agricultural Experiment Station

DOI: 10.1007/BF00147186

Cite this article as:
Nishiyama, I., Miyazaki, T. & Sakamoto, S. Euphytica (1975) 24: 197. doi:10.1007/BF00147186


The role of polyploidy in the evolution of the sweet potato. I. batatas (2n=6x=90), became more clear in 1971 when wild species with 30, 60, and 90 chromosomes were discovered. These species, I. leucantha (2x), I. littoralis (4x) and I. trifida (6x), are the progenitors of the sweet potato (6x), in an autopolyploid series with doubling of the I. leucantha B genome.

In the present study the hypothesis of the origin of the sweet potato was confirmed by comparative studies on some plant characters, sexual compatibility, and the behavior of artificial hexaploids produced from I. leucantha (2x) and I. littoralis (4x).

Since induced hexaploid I. leucantha exhibits weak growth, a few multivalents are formed at meiosis in the sweet potato, and there are differences in morphological and physiological characteristics between the artificial hexaploids and I. batatas, raw autoploidy seems unlikely, but a balanced or diploidised autoploidy could have been achieved by genic and chromosomal changes in the course of evolution. However, there is still sufficient homology so that meiotic pairing occurs usually between regular partners but also between homoeologous chromosomes in a certain situation.

Copyright information

© H. Veenman En Zonen B.V. Wageningen 1975