To: "Martha L. Davis" <martha_davis@earthlink.net>, North American Fruit Explorers <nafex@lists.ibiblio.org>
Subject: Re: [NAFEX] Genetics of sweet kernel Apricots
Date: Thu, 10 Apr 2008 20:31:10 -0700
There is some information about apricot development in Advances in
Fruit Breeding, edited by Jules Janick and James N. Moore, Purdue
University Press. I have the 1975 edition, but I've been reading the
1996 one online - the entire chapter is not available, but a good
sampling. The name of the book has changed to Fruit Breeding, and it
is published by John Wiley and Sons.
Apricots are not widely adapted. Whenever a cross is made with an
apricot from a different area, qualities that are disadvantageous
appear. For instance, improving cold hardiness can increase
susceptibility to disease.
Sweet kernels are present in two groups:
The Central Asian group - Greatest variation. Most self-unfruitful.
High sugar content, small to medium sized. Vigorous, long-lived, bloom
late. Susceptible to fungus diseases so need to grow in a dry area.
Irano-Caucasian group - . Most self-unfruitful. Often white or light
fruit, larger than Central Asian ones. Less winter-hardy. Bloom
earlier.
Bitter kernels are in this group:
European group - Not very variable. Some can withstand greater cold
while dormant than the above. Mostly self-fertile. Fruit orange, more
acidic, all ripen within a month. Greater resistance to fungus
diseases.
When crossing Central Asian apricots with Europeans, these qualities
of the Central Asian apricots predominate: small fruit, relatively
large pit size, increased sugar and decreased bitterness of flesh,
longer period of winter dormancy, later flowering, increased winter
hardiness, less resistance to fungal diseases. No mention of pit
taste. Some of these qualities are desirable, and others not.
In British Columbia, some Irano-Caucasian cultivars were used to
broaden the genetic base. It is possible that some of the Summerland
trees have sweet kernels.
Harrow, in Ontario, does not include kernel taste in its evaluation
sheet (shown online).