The Application of Ooubled Haploid Plants to Population ... - MSpace

5.5
plant from each line. The OH plants were randomly intercrossed in isolation tents
covered with clear plastic containing 2mm holes and bnrsh pollinated every other day
with a feather duster in the greenhouse for two generations to produce composite
populations (Cl and C,). There were two replicates grown for each of DSC-3 and
Reward DH populations. The position of the plants in the pollination tent was rotated
every 4 days after flowenng began. Seed was harvested frorn single plants and an
equal amount from each plant was cornposited to produce the first generation
composite (Cl). From each of these C, populations, 60 plants were seeded in
individual pots and randornly intercrossed to produce the second generation composite
(C) The composite population size was set at 60 individual plants after one
generation of intercrossing regardless of their original size to ensure adequate seed
production for the 1996 field season. The Reward Cl and C, populations were
evaluated in the field (1996) and single plants were sampled and analyzed for genetic
variation.
Plant Mafen'als
RAPD analysis was performed on populations of 22 and 23 OH lines derived
from breeding line DSC-3 and cv Reward, respedively.
At the 4 -5 leaf stage, al1 leaves ftom 10 - 15 plants of each DH line were
excised and pooled. The OH Iines were grown under controlled conditions in a growth
chamber. At the 5 - 6 leaf stage, 4-5 leaves ftom randomly seleded single plants were
excised in the field and individually prepared for DNA analysis. Each individual plant