The efficiency of visual selection in early generations of a potato breeding programme

Abstract

The efficiency of visual selection in the early generations of a potato breeding programme is examined. Tubers from 571 potato genotypes were scored by four breeders after being grown, from true seed, in a glasshouse and in the field for three consecutive years. The four breeders were in good agreement as to which clones would be selected in any environment. The association between breeders was greatest when the clones were grown in plots in the field. All correlations of breeders' preferences between different environments were significantly greater than zero, but only accounted for a small percentage of the total variation. Selection in both the glasshouse and first clonal year produced a desirable response. However, such selection carried a high cost in terms of losing clones with commercial potential. Comparison of a random sample of clones with ones from the same crosses which had been selected, indicated that selection in the glasshouse and first clonal year was at best random with some suggestion, however, of a negative effect.

Repeatability of family means in early generations of potato under heat stress

“…This would indicate that family selection for yield targeting heat tolerance could be performed in the warm season and in FCG with positive response to any environment, provided that the selection intensity is > 30 %. This idea is consistent with the studies of Brown et al (1987b) on potato and on sugarcane by Jackson et al (1995). One way to exploit family selection for yield would be to assess a higher number of families in a greenhouse, or in FCG, at warm temperatures, using a high selection intensity (Hogarth et al 1997).…”

“…At the level of individual clones, the correlations were low and non-significant, except for FCG x SCG. This result indicates that selection for tuber yield of individual clones would be advisable in the early generations (SG and FCG), as also demonstrated by Martin (1984), Swiezynski (1984), Caligari et al (1986) and Brown et al (1987b).…”

The use of multivariate cross prediction methods in the breeding of a clonally reproduced crop (Solanum tuberosum)

“…The growing conditions and experimental design used for the seedlings in the glasshouse, and the clones in the first clonal year were described by Brown, Caligari, Mackay and Swan (1984). Those for the second and third clonal generations were given by Brown et al, (1987 In each year, at each site, individual plots were harvested and taken into storage. The total weight and number of tubers were recorded for each plot and from these, mean tuber weights were calculated.…”

The use of univariate cross prediction methods in the breeding of a clonally reproduced crop (Solanum tuberosum)

“…For a description of the Scottish Crop Research Institute (SCRI) potato breeding programme see Holden, 1977 andMackay, 1982. However, all the other problems of selection efficiency are still pertinent and studies have shown that such conventional phenotypic selection in the early generations is relatively ineffective (Brown, Caligari, Mackay and Swan, 1984;Brown, Caligari, Mackay and Swan, 1986). It would therefore seem appropriate to investigate cross prediction methods in potatoes, particularly as have reported that progeny means were repeatable over the early generations, even though the environments in which different generations were raised were as diverse as seedlings in small pots in a glasshouse to material grown in the field from tubers.…”