Affiliation:
1. Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, Hubei, 430074, P.R. China
2. Department of Natural Resources and Environmental Sciences, University of Illinois, 1201 W. Gregory, Urbana, IL 61801, USA
3. Department of Biology, University of Massachusetts Boston, Boston, MA 02184, USA
Abstract
Gu, C., Wang, L., Korban, S. S. and Han, Y. 2015. Identification and characterization of S-RNase genes and S-genotypes in Prunus and Malus species. Can. J. Plant Sci. 95: 213–225. Most Rosaceae fruit trees such as Prunus and Malus species exhibit gametophytic self-incompatibility that is genetically controlled by the S-locus. In turn, the S-locus contains at least two tightly-linked S-determinant genes, a pistil S-RNase and a pollen SFB. In this study, S-genotypes of 120 cultivated and wild Prunus accessions (peach) and seven wild Malus accessions (crabapple) have been characterized. Among cultivated Prunus genotypes, four S-RNase alleles, designated S 1 , S 2 , S 3 , and S 4 , have been identified, and they share typical structural features of S-RNases from all other self-incompatible Prunus species. Four S-genotypes, S 1 S 2 , S 1 S 3 , S 1 S 4 , and S 2 S 2 , were identified in peach cultivars, while only one S-genotype S 1 S 2 for wild Prunus species. The S 1 S 2 genotype is predominant in peach cultivars, accounting for 58.3% of all evaluated accessions. Similarly, four SFB alleles were identified in peach cultivars and wild accessions. However, all the four SFB alleles encode truncated proteins due to a frame-shift mutation, resulting in loss of hyper-variable and/or variable regions. For Malus species, a total of 14 S-RNase alleles are identified, and of those, two alleles encode truncated proteins. Overall, the genetic variation of both S-RNase and SFB genes in peach is significantly lower than that of S-RNase and SFB genes in self-incompatible Malus and/or Prunus species. The relationship between the genetic variation of SFB genes and the diversification of S-RNase genes in Rosaceae is also discussed.
Publisher
Canadian Science Publishing
Subject
Horticulture,Plant Science,Agronomy and Crop Science