hybrids: fertility studies and tuber evaluation.
Rare pentaploid plants have been reported from interspecific artificial hybridization (Johnston, 1975; Burton et al., 1993).
Cluster E contains one tetraploid and three pentaploid accessions (Fig.
Multivalents comprised of 6 and 7 chromosomes per cell increased significantly (P < 0.05) in the 39 chromosome aneuploids over the pentaploid
hybrid, suggesting that the chromosomes are remaining as unpaired or being included in higher order chromosome associations.
Second-order models for tetraploids and pentaploids. Heredity 68: 205-210.
In tetra- and pentaploid hybrids, the problem of assuming equal "affinities" increases even more (Kimber & Alonso, 1981; Chapman & Kimber, 1992b), but still only two different values of relative "affinity" are allowed.
combinations ([A.sup.r][A.sup.n][B.sup.c][C.sup.n][C.sup.c]) between synthetic hexaploid plants ([A.sup.r][A.sup.r][B.sup.c][B.sup.c][C.sup.c][C.sup.c]) and cultivars of natural B.
as male parent in backcrosses with G.
Because PI 409704 is a pentaploid
(2n = 5x = 45), common buffelgrass was used as an internal standard for all PI 409704 seedlings.
These data are the first evidence of pentaploids
among buffalograss, in data from clones (Table 1) as well as progeny in seed populations (Table 3), most notably the cultivar 315.
As with pentaploids
, hexaploids are also the result of 2n + n matings and are considered [B.sub.III], derived hybrids.
Twenty-one plants surveyed were known to be either tetraploid, pentaploid
, or hexaploid.