140
Fig. 6.2 Metaphase I pairing in Giemsa stained cells of wheat × Ae. longissima hybrids. ( a ) Low
pairing level in the wild type genotype. ( b ) Intermediate pairing level in the ph2b mutant. ( c ) High
pairing level in the ph1b mutant
Table 6.2 Average number of chromosome confi gurations at metaphase I in hybrids of wild type,
ph2b and ph1b mutant wheat (ABD) with rye (R), Ae. longissima (S l ), Ae. sharonensis (S sh ), and
Ae. speltoides (S)
Hybrid I IIrod IIring Multiv Bonds/cell No. of cells
ABDR 26.31 0.80 0.03 0.01 0.88 500
ph2b ABDR 19.23 3.04 0.57 0.51 5.26 500
ph1b ABDR 11.76 2.33 2.36 2.16 12.35 500
ABDS l 24.55 1.59 0.06 0.05 1.81 300
ph2b ABDS l 14.93 5.08 0.58 0.55 7.44 300
ph1b ABDS l 3.48 4.04 2.99 2.86 18.28 300
ABDS sh 25.21 1.18 0.03 0.03 1.29 250
ph2b ABDS sh 10.16 5.58 1.42 1.13 11.17 300
ph1b ABDS sh 4.37 3.74 3.79 2.39 17.93 300
ABDS 3.97 4.09 3.11 2.61 17.79 100
ph2b ABDS 3.25 3.41 3.28 3.02 19.41 100
ph1b ABDS 2.53 3.36 4.29 2.68 20.08 100
Data for the three ABDR hybrid combinations correspond to cells studied for other purposes by
Naranjo et al. ( 1987 , 1988 ). For ABDS l hybrids see Naranjo and Maestra ( 1995 ), Maestra and
Naranjo ( 1997 ) for ABDS sh hybrids and Maestra and Naranjo ( 1998 ) for ABDS hybrids
through homoploid hybridization (Marcussen et al. 2014 ). How ever, the preferential
A–D pairing consistently observed in the hybrids denotes a much lower differentia-
tion between these two genomes than between A and B or B and D, at least in the
highly recombinational distal chromosome region.
T. Naranjo and E. Benavente