Plants – Rose – Climber
Plant Patent
1999-08-12
2002-03-12
Campell, Bruce R. (Department: 1661)
Plants
Rose
Climber
Plant Patent
active
PP012443
ABSTRACT:
TECHNICAL FIELD
This invention is directed to an apple rootstock.
BACKGROUND OF THE INVENTION
‘Malling 9’ rootstock is susceptible to crown and root rots and extremely susceptible to fire blight.
The goal herein was a dwarfing apple rootstock that is resistant to fire blight.
SUMMARY OF THE INVENTION
The present invention relates to a new and distinct cultivar of apple tree rootstock, ‘Geneva 16’, which we discovered in a test planting belonging to New York State Agricultural Experiment Station, Cornell University, Geneva, Ontario County, New York. This discovery is a product of the apple rootstock breeding program of the New York State Agricultural Experiment Station (‘Station’).
Origin: In March, 1981, pollen was collected from a
Malus floribunda
cv. 821 apple tree and used to pollinate emasculated flowers of a
Malus×domestica
cv. Ottawa 3 apple tree growing in Station greenhouse No. 13. The seeds were harvested from fruit produced from this cross and were stratified in November, 1981. After stratification, 560 germinating seeds were planted in a Station greenhouse in January, 1982. When the emerging seedlings were about 2.5 cm tall, they were inoculated with 15 isolates of the fungi
Phytophthora cactorum
and
Phytophthora megasperma
, which are causal agents of certain crown and root rots. The flats were flooded to mid-hypocotyl level of the seedlings, and kept at about 23° C. for seven days; 127 seedling survived this treatment. The surviving seedlings, when 10 to 15 cm tall, were inoculated in their shoot tips with about 10
6
cells of isolate Ea 273 of the bacterium
Erwinia amylovora
, the causal agent of the fire blight disease, using a 26-gauge hypodermic syringe. Three subsequent inoculations with
E. amylovora
isolate Ea 273 were made in summer and autumn, 1982. All but 14 of the seedlings were discarded for susceptibility to fire blight or were killed by fire blight. The seedling designated 6103FL-016, later tested as CG.16 and now named ‘Geneva 16’, was very resistant. Lesions that developed from the greenhouse inoculations and later in the field were less than 1 cm long, with some <1 mm long. Later, lesions 2 to 2.5 cm long developed when CG.16 shoots were inoculated with E4001A, a very virulent strain of the bacteria. The survivors were inoculated repeatedly with woolly apple aphids (
Eriosoma lanigerum
); very susceptible individuals were discarded. Seedings with very small leaves and those displaying either root initials or spines were also discarded.
The plant now designated ‘Geneva16’ was moderately susceptible to woolly aphids when inoculated with the local wild type. Leaves and fruit of ‘Geneva16’ are immune to apple scab (
Venturia inaequalis
) (CG.16's pollen parent,
Malus floribunda
cv. 821, carries the Vigene for immunity to scab). Leaves and shoots are moderately susceptible to powdery mildew (
Podosphaera leucotricha
).
We planted the 14
Erwinia amylovora
-resistant seedlings as trench layers on the Station's Loomis Farm in April, 1983. Rooted liners were harvested in late fall 1984 and were planted in the Station nursery in the spring, 1985. Maiden trees of the cultivars ‘Topred Delicious’, ‘Pagenelli Delicious’, ‘Summerland McIntosh’ and ‘Mutsu’ were produced by grafting onto ‘Geneva 16’ liners. These trees were subsequently planted in trial orchards at the Station and at the United States Department of Agriculture Appalachian Fruit Research Station, Kearneysville, W. Va.; Washington State University Tree Fruit Research and Extension Center, Wanatchee, Wash; Littletree Orchards, Newfield, N.Y.; and Brown Orchards, Ithaca, NY.
In these test plantings, trees on ‘Geneva 16’ were similar in size to those on ‘Malling 9’ EMLA rootstock, based on comparison with the check trees in the same testing plantings. None of the trees on other clones from the ‘Ottawa 3’×
Malus floribunda
family were dwarfed. Trees on ‘Geneva 16’ began flowering early, usually the second year in the orchard; this wes especially noteworthy for ‘Mutsu’ cultivar, which in New York normally begins fruiting in the third or fourth year when grafted on the precocity-inducing rootstock ‘Malling 9’. All of the culivars that have been tested on ‘Geneva 16’ have demonstrated high production efficiency, similar to that experienced with the very efficient ‘Malling 9’ rootstock.
Compatibility: We have observed no symptoms of incompatibility with 26 trees of the four fruiting cultivars mentioned above. Besides these, we have grafted ‘Jonagold’ on ‘Geneva 16’; in the nursery we have observed no symptoms of incompatibility. All scionwood used was free from known harmful viruses. Virus sensitivities of ‘Geneva 16’ are not known.
Propagation: We have propagated ‘Geneva 16’ asexually by budding and grafting onto seedling and clonal rootstocks; by root cuttings; by hardwood cuttings; by greenwood cuttings; and by conventional layering. These asexual propagules have remained true-to-type with these methods of asexual propagation.
We have also propagated ‘Geneva 16’ readily in vitro. ‘Geneva 16’ appears not to be prone to epigenetic changes induced by the growth regulator environment in the tissue culture medium. In layerbeds established with micropropagated ‘Geneva 16’ plants, rooting has been superior to that observed in conventional layerbeds.
We have also used ‘Geneva 16’ as a pollen parent in our breeding program; since ‘Geneva 16’ is highly heterozygous, its seedlings are much different from both parents and from each other, but the excellent resistances to Phytophthora and to
Erwinis amylovora
transmitted to a substantial percentage of progeny.
Aldwinckle Herbert S.
Cummins James N.
Campell Bruce R.
Cornell Research Foundation Inc.
McCormick Susan B.
LandOfFree
Apple rootstock named ‘Geneva 16’ does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apple rootstock named ‘Geneva 16’, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apple rootstock named ‘Geneva 16’ will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2877534