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SNA RESEARCH CONFERENCE - VOL. 40-1995
Loropeta/um chinense
rubrum
Nick J. Gawel and G.R. Johnson
Tennessee
Nature of Work: The distinctness of Loropetalum chinensevar. 111b111mcultivars were examined using a DNA fingerprinting technique.
L. chinensevar. rubrum is an Asiatic evergreen shrub with many desirable landscape characteristics: it is fast-growing, tolerant to disease and insects, and produces attractive flowers. Recently, the horticultural community has shown an increased interest in the species since pink-flowering selections (L. chinensevar. 111b111nfi have become available. Due to the relatively rapid introduction and rapid commercialization of these introductions, there has been some confusion concerning the identity and distinctness of cultivars. This research examined the DNA of rubrumaccessions, and
14 L. chinensevar.
2 accessions of L. chinenseto determine the genetic diversity among the cultivars. The DNA was examined using the Randomly Amplified Polymor­ phic DNA (RAPD) technique.
Results and Discussion: Figure 1 presents the results of a Principal Components
Analysis based on the differences in DNA between the accessions examined. Results indicate that many of the accessions are very closely related to at least
1-2 other accessions. Accessions being propagated under the same cultivar name exhibited minimal diversity. Most named accessions had very closely related unnamed acces­ sions.
Significance to Industry: These results provide growers with a basis for decision­ making to avoid redundancy in cultivar propagation. Also, the data presented are useful when making breeding decisions concerning L. chinensevar. rubrum, and for those interested in determining which accessions will contribute the most or least genetic diversity to a collection.
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SNA RESEARCH CONFERENCE - VOL. 40-1995
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J.l. Sibley, D.J. Eakes, C.H. Gilliam, G.J. Keever and W.A. [
Alabama
Nature of Work: A trend towards production and use of red maple cult tales determination of characteristics by which cultivars can be readily of these characteristics have been described in publications available f nursery industry. Previous studies have reported differences in red mar terms of growth and fall color
(1, 4, 7), leaf greenness (2), and canopy
(6) gave general descriptions of
10 Acer rubrum and four A. x freeman these were largely individual and not comparative. As pointed out by D
(3), the opportunity to evaluate related trees in a single location is a se luxury. Often the only observational data available have been collectec growing conditions, and as such are difficult or impossible to compare ,
The purpose of this study was to complete a comparative evaluation ot maple cultivars grown under the same environmental conditions in ord1 the trees based on differences in average leaf area, petiole length, an2 ogy, and appearance. A unique feature of this study was to compare rE previously reported to pertorm well in the Southeastern United States ( selections from the Freeman maple group. Maples in this category are considered as red maple cultivars, but are classified botanically as A. > indicating their hybrid origin. These maples are interspecific crosses b< and A. saccharinum.
Red maple cultivars were obtained in March 1988 as tissue culture mic
(Microplant Inc., Fairview, OR). Trees were containerized and grown le under standard nursery practices, ranging in height from 4
•
5 ft when I
March
1990, at the Piedmont Substation, Camp Hill, AL. Trees were pl
35 ft spacing in
5 blocks of 2 plants each for a total of
1
O trees per cult fertilized at planting and annually in March prior lo bud break with 1 lb phosphorus (P), and potassium (K), as
13-13·13, per
1 in of caliper at level and were supplied with drip irrigation, thereby eliminating moistur cerns.
379