Gains from family and visual selection in sugarcane, particularly for heavily lodged crops in the burdekin region

摘要

In the Burdekin region, sugarcane is grown under irrigation, resulting in large and frequently lodged crops, which prohibit visual selection. The effectiveness of family selection in original seedlings followed by visual selection in the young ratoon crop was investigated for this region. Family selection based on the selection index, net merit grade (NMG), was effective in identifying families with a high proportion of elite clones (clones that combine good cane yield and sugar content). However,elite clones could also be identified in families with relatively poor performance, so that any form of family selection would have to be liberal. Combined family and visual selection was even more effective than family selection alone, and visual selection was effective in identifying elite clones in both the good and relatively poor families. Gain from family selection was consistent up to a selection rate of 30 percent. It is proposed that the top 30 percent of families be chosen for routine visual selection. Thereafter, progressively fewer clones should be selected from the intermediate 40 to 50 percent of families. Families with moderate to low NMG that have extremely high sugar content but low cane yield and vice versa should also be targeted forany outstanding clones. The time required to select from these relatively poor families would not be a limiting factor in a field operation, as such plots can be predetermined using family data. An added advantage of family selection is the use of family data to select parents, since the breeding value of parents can be determined from progeny performance. Overall, this can only mean a more effective and efficient breeding program for the Burdekin region.