Abstract
The diploid maritime grass Thinopyrum bessarabicum (2n=2x=14, EbE
b
) hybridized with bread wheat (Triticum aestivum L.,
2n=6x=42, AABBDD) yielding a self-sterile F1 intergeneric hybrid (2n=4x=28, ABDEb
). By back or top crossing, the hybrid
with bread wheat cultivars, individual disomic Th. bessarabicum chromosome addition lines were produced with 44
chromosomes (2n=6x=42 + 2 = 44; AABBDD + 1Eb1Eb
to 7Eb7Eb
). Also, earlier produced by using F1 hybrid clones were the
colchicine induced amphiploids (2n=8x=56; AABBDDEbE
b
). These genetic stocks were produced and maintained by the wide
cross program at National agriculture research center (NARC) and studied cytologically and phenologically. The disomic
chromosome additions are a conduit towards providing information on trait associations with grass chromosomes after stress
screening, followed by cytogenetic manipulations to effect subtle alien chromatin transfers into homoeologous chromosomes
of wheat. Each addition line was stable at 44 chromosomes, possessed regular bivalent meiosis and high fertility. The
amphiploid was also cytologically normal. Phenological details permitted some additions to be readily characterized as follows:
tapering spike = group 2Eb2Eb
, solid stem = group 3 EbE
b
, blue aleurone seed = group 4 EbE
b
and club shaped spike = group 5
E
bE
b
. The seed repository in Pakistan is the wide cross program in NARC, Islamabad.
