A total of three straw hulled, awnless (biotypes
1, 2, 3) and one black hulled, awned (biotype 4)
red rice plants were collected at a south Louisiana
commercial rice field in the summer of 1996 and
used in greenhouse crosses with non-transgenic
Bengal and Cypress cultivars and Liberty resistant
transgenic lines (Table 1). An additional strawhull, awnless red rice, designated biotype 5, has
been previously characterized for seed dormancy
[19–21] and was included as a control. The transgenic
BAR lines were previously shown by laboratory
and field tests to contain one or more stably
incorporated copies of the BAR gene and express
tolerance to 1.1 kg a.i.:ha field applications of
Liberty herbicide [22]. F1 seeds were planted in the
greenhouse for seed increase during the winter of
1996–1997. F2 seeds were harvested in the spring
of 1997 and dried to 12% moisture for field planting.
From each F2 population ten seeds were
tested for germination using a standard 7-day test
[21]. Only those seed lots with germination percentages
higher than 85% were planted in field
experiments.