The Confirmation of Ploidy Periclinal Chimera and its Morphological Characteristics in Meiwa Kumquat ‘Yubeni’

Abstract

The cultivar ‘Yubeni’ was discovered as a mutant of Meiwa kumquat (Fortunella crassifolia Swingle) in Kushima city, Miyazaki. According to the results of flow cytometry analysis and morphological investigation of several tissues and organs, ‘Yubeni’ was supposed to be a ploidy periclinal chimera with diploid (2n = 2X = 18) in the outermost layer (histogenic layer L-I) and tetraploid (2n = 4X = 36) inner layer (histogenic layer L-II and L-III) in the shoot apical meristem. Compared with the diploid line, it showed similar morphology to the tetraploid line such as larger leaves, flowers and pollen grains. The weight and size of the fruit were both greater than those of the diploid line. Furthermore, this cultivar has desirable traits for kumquat such as smaller number of developed seed and thicker pericarp.