Fluorescent Staining Analysis of Chromosomes in Pear (Pyrus spp.)

Abstract

Fluorescent banding patterns of pear chromosomes were determined from samples taken from root tips of openpollinated seedlings of six cultivars from three species [Pyrus pyrifolia (Burm. F) Nakai (Japanese pear), P. communis L. (European pear), and P. bretschneideri Rehder (Chinese pear)]. Root tips were pretreated in 2 mM 8-hydroxyquinoline at 10°C for 4 h; the chromosome samples were prepared by the enzymatic maceration and air-drying method. All cultivars used in this study had 2n = 34 chromosomes. Chromomycin A 3 (CMA) positive (+) bands were observed in telomeric positions of four chromosomes. In some samples, these CMA + bands were observed at satellite positions. 4'-6-diamidino-2-phenylindole (DAPI) negative bands (−) were seen to correspond with CMA + bands. Thirty chromosomes had no CMA +/DAPI − bands. No propidium iodide (PI) bands were observed in any chromosomes. The number and positions of CMA + bands were stable, and there was no difference among the three species.

Recent Progress on Studies of Chromosome Observation in Deciduous Fruit Trees

“…Table 1 shows a list of the applications of the enzymatic maceration method in deciduous fruit trees. The conditions of the enzymatic treatment of Prunus, Malus, Pyrus, and Diospyros have been elucidated in several studies (Maghuly et al, 2010;Minamikawa et al, 2010;Omura, 1988;Schuster, 1996;Schuster et al, 1997;Yamamoto et al, 1999aYamamoto et al, , 2010aZhuang et al, 1990). In all species, cellulase in combination with pectinase or pectolyase was essential for chromosome sample preparation.…”

“…Good chromosome samples prepared by the EMA method allowed further subsequent studies on counting the chromosome number (Zhuang et al, 1990), karyotyping (Omura, 1988), fluorescent staining (Yamamoto et al, 1999a(Yamamoto et al, , 2010a, FISH (Maghuly et al, 2010;Minamikawa et al, 2010;Schuster et al, 1997;Yamamoto et al, 2010b), and GISH (Choi et al, 2002(Choi et al, , 2003b.…”

“…Thirty chromosomes had no CMA+/ DAPI− bands. No propidium iodide (PI) bands were observed in any chromosomes (Yamamoto et al, 2010a) (Fig. 3).…”

Fluorescent Staining and Fluorescence in situ Hybridization of rDNA of Chromosomes in Pear (Pyrus spp.)

“…F) Nakai (Japanese pear) 'Osa Gold' and 'Niitaka', P. communis L. (European pear) 'La France' and 'Max Red Bartlett', and P. bretschneideri Rehder (Chinese pear) 'Enli' and 'Yali'] showed the same chromosome configuration: CMA-positive (+) and DAPI-negative (−) bands were observed in telomeric positions of four chromosomes (Yamamoto et al, 2010a). FISH analysis revealed the 18S-5.8S-25S rDNA sites of open-pollinated seedlings of Japanese pear 'Osa Gold' and European pear 'La France' in telomeric positions of six chromosomes (Yamamoto et al, 2010b).…”

“…In the present study of fluorescent staining, native species of Japan were mainly used as materials. The detailed results of fluorescent staining of 'Osa Gold' have already been reported (Yamamoto et al, 2010a).…”