Correlations of Chilling Requirements for Germination, Blooming and Leafing within and among Seedling Populations of Almond1

Relationships among blooming and leafing dates of parents, offspring, and the chilling requirements of the intervening seed were determined among a group of families of almond ( Prunus amygdalus Batsch). Parentoffspring heritabilities for blooming and leafing dates were high. Leafing and blooming dates of individuals and families, although significantly correlated, were more or less independent traits. Seed chilling was a function of both seed and pollen parents and was correlated with mean bloom and leafing of parents. The correlation coefficient between chilling of a seed and the blooming date of the corresponding offspring plant was significant and large when calculated for families and significant, but low, when calculated for individuals. The seed-leafing correlation was significant when the early and late leafing progeny were considered separately.