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.

The Confirmation of a Ploidy Periclinal Chimera of the Meiwa Kumquat (Fortunella crassifolia Swingle) Induced by Colchicine Treatment to Nucellar Embryos and Its Morphological Characteristics

“…In previous studies, the composition of each histogenic layer in periclinal chimeras such as the ploidy and the graft chimera was evaluated by morphological examination [11,12,20], histological observation [8][9][10], componential analysis [8], FCM analysis [12], and molecular biological techniques [7,9,10]. To clarify the ploidy level of each histogenic layer in the 2x+4x ploidy chimera, in the present study, flow cytometric analysis, cell observation, and morphological examination of several tissues and organs were carried out.…”

“…In the genus Citrus and its related genera, on the other hand, the juice sac is often used to analyze the origin of L1 [8,9,12]. Zhang et al [8] demonstrated the origin of L1 by investigation of the carotenoid composition of the juice sac in periclinal graft chimera "Zaohang" navel orange composed of Robertson navel orange and Satsuma mandarin.…”

“…), Yubeni which have a large fruit size and a high sugar content was discovered to be a bud mutation of the Meiwa kumquat. Yasuda et al [12] demonstrated that Yubeni was a ploidy periclinal chimera with diploid cells in the outermost layer (L1) and tetraploid cells in the inner layers (L2 and L3) of the shoot apical meristem, and showed that the Yubeni increase in fruit quality was due to the tetraploidization in L2 and L3. Furthermore, this result showed that the 2x-4x-4x ploidy periclinal chimera kumquat could be used both for the parental line in triploid breeding and for direct domestication.…”

“…Furthermore, this result showed that the 2x-4x-4x ploidy periclinal chimera kumquat could be used both for the parental line in triploid breeding and for direct domestication. However, since the ploidy chimera kumquat has rarely been reported [12], information on their characteristics is lacking. To prove the future usefulness of the ploidy chimera kumquat, it is necessary to evaluate more kinds and collect information.…”

Triploid and Aneuploid Hybrids from Diploid-diploid Intergeneric Crosses between Citrus Cultivar ‘Kiyomi’ Tangor and Meiwa Kumquat (Fortunella crassifolia Swingle) for Seedless Breeding of Kumquats

“…'Yubeni' is a ploidy periclinal chimera derived from bud mutation in the Meiwa kumquat (Yasuda et al, 2008). 'Puchimaru' is an interspecific hybrid derived from a cross between an oval kumquat [F. margarita (Lour.)…”