CYTOTYPE VARIATION IN THE NATURAL POPULATIONS OF ACTINIDIA CHINENSIS COMPLEX IN CHINA

Y.F. Liu, D.W. Li, H. Huang
The Actinidia chinensis Planchon, including A. Chinensis var. chinensis and A. Chinensis var. deliciosa, is a diploid-polyploid species complex. Both varieties in this complex are commercially important. To better understand the cytotype distribution, ecological adaptation and to facilitate breeding of the two varieties, the ploidy variations in their natural populations were examined by flow cytometry in both large and small scale spatial ranges in the central-west China. In total, 338 individuals sampled from 16 natural populations in a large scale spatial range and 245 individuals continuously sampled in a small scale spatial range were included in this analysis. As a result, four ploidy levels of diploids, tetraploids, pentaploids and hexaploids were found, in which A. Chinensis var. chinensis are diploids and tetraploids, and A. Chinensis var. deliciosa are tetraploids, pentaploids and hexaploids. In the large scale spatial range, the distribution of diploids and hexaploids are geographical segregation, but the tetraploids are geographically mixed with diploids or hexaploids. Moreover, significant geographical segregation relating to altitudes and latitudes of three cytotypes has been found in the small scale spatial range focused. In both spatial scales, the total cytotype distribution shows a pattern in which the ploidy levels declined continuously as the altitudes decreased or longitudes increased. Moreover, cytotype mixture has been found to occur in many natural populations of this species complex. Possible eco-genetic mechanisms relating to cytotype mixture and the potential hybrid zone of two varieties have been discussed. All of these results are expected to provide new baseline data for the domestication and breeding of kiwifruit.
Liu, Y.F., Li, D.W. and Huang, H. (2011). CYTOTYPE VARIATION IN THE NATURAL POPULATIONS OF ACTINIDIA CHINENSIS COMPLEX IN CHINA. Acta Hortic. 913, 157-162
DOI: 10.17660/ActaHortic.2011.913.18
https://doi.org/10.17660/ActaHortic.2011.913.18
altitudinal gradient, breeding, cytotype distribution, hybrid zone
English

Acta Horticulturae