The mass selection reservoir and sugarcane selection.

A method is proposed which extends the mass reservoir technique to the breeding of clonally propagated crops. The first phase produces a diverse array of clones by sexual recombination. Then the selection phase is conducted in one genotypically heterogeneous population. Such a population is termed a mass selection reservoir (MSR). In each generation of agricultural bulk planting, competitive ability is supplemented with a regime of artificial selection among propagules for fixing the rate at which each component genotype is advanced.A MSR programme has been initiated in sugarcane in Fiji. An analysis of the variation in selection characters demonstrated significant clonal effects at the single stalk (propagule) level. Sugar concentration was particularly repeatable on this basis. After two generations of selection, the MSR's performance at the population level at least equalled that of the best current commercial clone, Ragnar. It is therefore likely to include superior isolates of one or more clones.Two possible artificial selection methods are compared. These arise from either a linear (L) or multiplicative (M) combination of the two major selection criteria, sugar concentration and stalk weight. Although the M series differs genotypically from the L series, there is little difference to date in their respective population performances.