MULTIVARIATE ANALYSES OF POTATO HYBRIDS. II. DISCRIMINATION BETWEEN TUBEROSUM-ANDIGENA HYBRID FAMILIES AND THEIR RELATIONSHIP TO THEIR PARENTS

Abstract

In 1978 17 families from crosses between Tuberosum and long-day adapted Andigena parents were compared with each other and their parents using ten-hill plots. The mean performance of all Tuberosum-Andigena hybrid families was between the performances of the parental groups for six of eight traits, while in the best families the means of some yield traits exceeded the best parent. Multivariate analysis of seven traits gave five significant canonical variates which accounted for 96.6% of the variation. Two dimensional canonical diagrams showed a considerable overlap of the hybrid families and the Andigena parents, but very little overlap of either of these with the Tuberosum parents. Canonical distances between the hybrid families and the parents showed the families to be closer to the mid-parent value than to either parent, and closer to the Andigena parent than to the Tuberosum parent. The results suggest that the genetic effects of the Andigena parents are stronger than those of the Tuberosum parents, while non-additive effects are also important. Only the better Andigena parents and hybrid families are close to or overlap the distribution of the Tuberosum parents. Discrimination between hybrid families and their relationship to their parents provides information of value in determining future breeding strategies.