Evaluating Combining Ability in Peach and Nectarine1

Abstract

Prepotency of 5 seed and 9 pollen parents of peach and nectarine, Prunus persica (L.) Batsch, was estimated from analysis of detailed data on 1,131 seedlings. Selections were compared as parents from percentages of transmission of 22 commercially important characteristics in multiple cross progenies. Three composite measures of combining ability delineated two of the selections as superior parents. One parent gave selections worthy of propagation at the rate of 1 per 33 seedlings, while poorer parents required as many as 752 seedlings to produce one selection.

Surface Features of a Novel Peach X Nectarine Hybrid1

“…Tender annual plants such as bean, corn and tomato can avoid frost in jury down to -5° to -7°C if they are free of ice nucleation active (INA) bacteria. The de gree of frost injury is proportional to the log of the bacterial population (4).…”

“…Presence or absence of pubescence is controlled by a single genetic factor (Gg) with nectarine the homozygous recessive genotype (6). Both the GG and Gg genotypes are peaches, but per sonal observation (V. E. Prince) and pub lished accounts (4,10) suggest that often the heterozygote has lighter pubescence. Other genes also affect the amount of pubescence present (6).…”

An Interactive Microcomputer Program for Development and Calculation of a Plant Breeding Selection Index

“…Genetic progress in improving overall merit using the index was only slightly less than selection for yield alone, suggesting that improvements in yield could be made with out sacrificing other desirable characters. Fogle (6) used weighted progeny data to ob tain cum ulative scores for identifying pre potent peach and nectarine parents. He concluded that percentage of selections from combined progenies did not necessarily de lineate the most prepotent parents.…”