Extra, Diminutive Chromosomes Inoenothera

MonoFour plants from the first generation were tested cytologically.Two of these had the normal diploid number (0 4, 5 pairs, in both cases).The other two had extra, diminutive chromosomes (7 pairs plus the extras).One of these plants had an extra pair of diminutives (fig.5), the other had three extra chromosomes (fig.123).Subsequent generations have been derived from the plant of the first generation which had 2 extras.Chart 1 shows the subsequent history of this race with respect to chromosome number.It will be noted that, starting with a plant having 7 ordinary pairs and an extra diminutive 165 15585646, 1951, 2,