Patent Grant
PP29217
Latin name of the genus and species of the tree claimed: The Coast Redwood tree variety of this invention is botanically identified as Sequoia sempervirens.
Variety denomination: The variety denomination is ‘Early Snow’.
The present invention relates to a new and distinct tree variety of Sequoia sempervirens, more commonly known as Coast Redwood tree, having naturally-occurring chimeric characteristics resulting in albinism vegetation.
Specifically, ‘Early Snow’ is a periclinal chimera exhibiting stable albino growth inside the apical meristem dome. The albinism emerges more prominently beginning in the first or second year of growth. Tests conducted by the first-named inventor reveal that the present invention has a survival tolerance with up to 65 to 70 percent albinism. The buds of the present invention contain several forms of naturally-occurring chimera, including: periclinal, mericlinal, and sectorial. The branches demonstrate color variation, including: green, albino, and chimeric, and non-chimeric variegation; and exhibit a horizontal-to-moderate drooping growth habit. Needle morpholgy exibits a dense, occasionally overlaping habit that is singularly arranged with a concave pattern. Additionally, certain favorable conditions, the present invention yields high propagation levels via stem and leaf cuttings.
The new variety originated as a result of an ongoing breeding program in Santa Cruz, Calif. The seedling of the present invention was grown from a controlled cross conducted in 1976 where an unnamed, unpatented albino Sequoia sempervirens providing the male pollen and the conelets of an unnamed, unpatented green Sequoia sempervirens were pollinated. After repeated experimental propagation efforts, asexually-reproduced leaf and stem cuttings took root in a greenhouse laboratory setting in Volcano, Calif. between the years of 2012-2015. These cuttings yielded the stable periclinal chimeric albinism growth characteristic of the present invention.
Coast redwood trees (hereinafter “redwood”) are well known in the industry for their disease and insect resistance, fast growth habit, fire tolerance, and for supporting wildlife habitat. Redwoods are also noted for their height and longevity. These characteristics have led to an increase of the use of this plant as an ornamental feature in landscaped gardens and re-forestation projects. Congruent with similar coast redwoods, the present invention is expected to reach a height of 18 to 36 meters, maintain tree form, and have a lifespan capacity of 200 to 1000 years.
Albinism in redwoods is a genetic mutation presenting chlorophyll deficiency in the plant's needles and stems. As chlorophyll is instrumental to glucose production and storage, albinism prevents a plant from providing food for itself; therefore, survival of albino growth is depended upon parasitic-type growth on the non-albino portions of the redwood. Albino redwoods (hereinafter “albino”) in the wild are typically found in two forms: aerial and basal. Aerial albinos consist of a mutated branch where the foliage grows white or yellow. Basal albinos consist of entirely white or cream colored basal sprouts growing off an otherwise healthy green redwood. A chimeric redwood is a single plant organism with two or more different genotypes originating from the same bud or meristem. The normal green genotype acts as a surrogate to support the growth and survival of the albino mutation. It is not a symbiotic relationship between two separate plants. Further, due to this dependency and lack of chlorophyll, pure albino redwoods are unable to be reproduced vegetatively.
White color variation is subject to environmental conditions, particularly light exposure. For example, when grown in direct sunlight conditions, albino redwoods may turn ivory, cream, or light yellow in color. In contrast, when growing under the canopy of surrounding tree branches, albino redwoods are white in color. Excessive heat and low humidity may also result in die-back of the albino portions of the redwood. Additionally, the variation and distribution of white coloration is influenced by the phenotypic expression of three different types of chimeric growth: periclinal, sectorial, and mericlinal.
Chimerism in plants is typically achieved artificially through grafting and controlled gamma ray irradiation of seeds. One example of a grafted chimera plant is the thornless rose. A second example of irradiated seeds producing chimeric growth is the African violet plant. The present invention, in contrast, is a naturally-occurring chimeric mutation observed through variegated apical stems.
In order to provide a clear and consistent understanding of the specification, the following definitions are provided:
A Zone. “A Zone” refers to a primary branch originating from a terminal bud. Coloration in the A Zone is predominantly green, but can range from range from albino, chimera, and non-chimeric variegation.
Albino. “Albino” refers to a white color variation ranging from ivory white to pale, yellow-green white, and is a result of a genetic mutation inhibiting chlorophyll production.
B Zone. “B Zone” refers to secondary branches developing from axillary and accessory buds from present or empty leaf axils with no primary branch present. They are commonly found between the internode of two primary branches. Coloration in the B Zone can range from albino, chimera, non-chimeric variegation, and less frequently green.
C Zone. “C Zone” refers to secondary branches developing from axillary and accessory buds in the region of the primary branch's axil or branch collar. Coloration in the C Zone can range from range from albino, chimera, non-chimeric variegation, and less frequently green.
Chimera. “Chimera” refers to the existence of more than one genotype present in one plant originating from the same bud or meristem. The chimeric phenotype is separated into three different categories based on the location and relative proportion of mutated to non-mutated cells in the apical meristem. These categories are mericlinal, periclinal, and sectorial.
Chimeric variegation. “Chimeric variegation” refers to a pronounced delineation of color with both green and white pigment in the meristems, branches, and needles.
Mericlinal chimera. “Mericlinal chimera” refers to a phenotypic expression in which only a small portion of the plant structure (stems, branches, and leaves) demonstrates chimeric albinism. This type of chimera is known in the industry to be unstable.
Non-chimeric variegation. “Non-chimeric variegation” refers to a partial lack of chlorophyll (and therefore green pigment) in plant cells and tissues where it is normally expected to be present. The pattern of variegation is unorganized and is differentiated at the cellular level between green and white. The variegation expression is mosaic in appearance.
Periclinal chimerism. “Periclinal chimerism” refers to a stable chimeric variegated mutation expressing albinism across the meristem dome. This leads to subsequent cell division of mutated and non-mutated cells within the meristem giving rise to a stable continuation of growth for both genotypes.
Primary. “Primary” as used in this application refers to branches and buds forming initially from the meristem with no rest period. Primary branches and buds develop within the “A Zone”.
Secondary. “Secondary” as used in this application refers to branches and buds forming after a rest period and are latent in nature. They develop from axillary and accessory buds after Primary branch development. Secondary branches and buds are found both in “B and C Zones”.
Sectorial chimera. “Sectorial chimera” refers to growth where mutated cells affect large sections of the apical meristem. Mutated tissue can extend through all cell layers within the meristematic tissue. The delineation line between both genotypes is usually vertical in arrangement through the meristem and between stomata bands in the leaves. This type of chimerism is known in the industry to be unstable.
The following traits represent the characteristics of the new redwood tree variety ‘Early Snow’. These traits in combination distinguish this variety from all other commercial varieties known to the inventors.
The initial cross took place in 1976 under the direction of the second-named inventor, combined the premature cones on the green redwood (Parent Two) with pollen collected from the albino redwood (Parent One). The conelets were then sealed with a plastic bag to prevent open pollination. Redwood seeds take a year to mature, so in late 1977, of the thousands of seeds present, 360 were randomly selected from the ripe cones. Within a couple of weeks, several tiny stems and cotyledons emerged displaying differences in coloration. The present invention is derived from one of the 161 surviving seedlings of this experiment. Further background on the original cross are detailed in the book entitled The White Redwoods: Ghosts of the Forest (Davis, D. & Holderman, D. 1980, Naturegraph Publishers. California. Pages 33-36).
At the time of application filing, ‘Early Snow’ demonstrates a moderate-to-fast tree-like growth habit. It is approximately 1.86 m tall with a pointed top and a stem nearly 1.9 cm in diameter. The limb spread is approximately 96.5 cm in diameter. Sections exhibiting periclinal chimera and green foliage appear more dense then it's sibling ‘Mosaic Delight’ (U.S. Plant Pat. No. 26,573, hereinafter ‘Mosaic Delight’). Forty percent of the present invention's branches exhibit periclinal chimeric growth with albino axillary bud growth. Propagated cuttings from the present invention already exhibit a faster growth rate than the original, first specimen. present invention A determination of growth rate for the cuttings is correlated with albinism. For example, when trees exhibit ratio of 0 to 25% albino foliage to green, they exhibit moderate to fast growth. With a ratio of 25 to 60% albino foliage to green, trees have a more moderate to slow growth rate. This expression reflects the impact of lower glucose levels in trees with high albinism and the effect on growth rate.
Past experimental propagation of ‘Early Snow’ underwent several propagation efforts and experienced several challenges in producing vigorous, stable specimens. Finally, the present invention has been successfully and repeatedly propagated asexually in a controlled nursery environment through vegetative, leaf and stem cuttings under the direction of the first named inventor. The first viable progation effort was conducted in the Fall of 2013 after the first-named inventor selected forty eight hardwood cuttings from the present invention. The cuttings were transported to a greenhouse located in Volcano, Calif. The cuttings were divided into stem cuttings, and dipped into a rooting solution consisting of 2500 PPM of IBA for approximately 10 seconds. Following this step, the stem cuttings were planted in gallon-sized pots and treated with a fungicide product. Between the Fall of 2013 through the Winter of 2013-2014, the cuttings were misted and given water at regular intervals. The cuttings were also provided supplemental lighting 24 hours a day. After 22 months in the propagation incubator 23 cuttings out of a total of 48 rooted. By the end of August of 2015 (second year), the cuttings demonstrated sharp increased albino growth from axillary and/or accessory buds forming within the internode and branch collar zone of the primary green branches.
The second propagation effort was conducted in the Winter of 2015 when the first-named inventor selected 14 hardwood cuttings. The cuttings were grown at the same greenhouse facility located in Volcano, Calif. and propagated under the same environmental conditions and protocol procedures carried out in Fall of 2013. By the Spring of 2016 (beginning the second year), the 7 surviving cuttings from both the 2013 and 2015 propagation groups demonstrated increased albino growth from axillary and/or accessory buds forming within the internode of primary green branches and within the branch collar zone of green branches. The results of the second propagation effort showed that they were consistent with the first.
Based on the results between the 2013 propagation group and the 2015 propagation group, the invention shows better rooting results with hardwood cutting propagation taken from summer growth rather than winter growth. During propagation experimentation, one cutting was selected for a fertilizer test and the conclusion of the test elucidates that a slow release fertilizer works best with ‘Early Snow’ and quick release fertilizers should be avoided. Tests have shown that cuttings from ‘Early Snow’ roots very easly in a favorable growing environment. Results have shown 48 to 50% of cuttings propagated rooted successfully with this invention.
The cuttings of ‘Early Snow’ have demonstrate that the combination of characteristics disclosed are stable and firmly fixed, and are retained true-to-type through the periclinal chimera genotypes. It is important to note that the invention can exhibit mericlinal and sectorial growth through the periclinal phenotype and therefore this growth is claimed within this invention. It is known in the literature that periclinal chimerism in plants is considered stable and as such, is readily available in commercial markets (Lineberger, R. No date. Origin, Development, and Propagation of Chimeras. Texas A&M University. Retrieved from http://aggie-horticulture.tamu.edu/tisscult/chimeras/chimeralec/chimeras.html on Jan. 20, 2014).
Table 1 illustrates variations in coloration and growth rate among six stem cuttings of the present invention.
Plant Breeder's Rights for this variety have not been applied for and ‘Early Snow’ has not been offered for sale more than a year before the filing date of this application, nor has it been offered for sale under another variety name. Since the original cross, cuttings of ‘Early Snow’ have undergone experimental use to solve prior propagation challenges and the present invention has not been publicly available during this time.
Plants of the present invention have not been observed under all possible environmental and cultural conditions. The phenotype may vary somewhat with variations in environmental conditions without, however, any variance in genotypes. For example, phenotypic expression may vary somewhat with fluctuations in temperature, light intensity and soil chemistry.
The accompanying colored photographs illustrate the overall appearance of the new and distinct albino redwood tree with periclinal chimerism showing the colors as true as it is reasonably possible to obtain in colored reproductions of conventional photography. The photographs were taken in a greenhouse setting under defused, natural lighting. Two typical specimens (Stem Cutting Numbers 1 and 4) of the present invention are included to demonstrate color variation on the leaves and stems produced by the chimeric and non-chimeric genotypes.
The following is a detailed botanical description of the new variety ‘Early Snow’. Data was collected from Stem Cutting Number 1 at 39 months-old in the Fall of 2016; presently growing in a greenhouse in Volcano, Calif. The growing conditions approximate those generally used in commercial practice. Color readings were observed indoors with natural lighting diffused through greenhouse panes. The color determinations are in accordance with the Fifth Edition (2007) of The Royal Horticultural Society Colour Chart published by The Royal Horticultural Society (London, England), except where general color terms of ordinary dictionary significance are used. Chimeric and non-chimeric expression among the propagated trees leads to a variation in color and, therefore, a color's hue, saturation, or intensity is generally depicted in The R.H.S. Colour charts through the follow color groups and ranges: RHS 4C-D, 8C-D (yellow group), 128A-149D (green group), and 155A-D, NN155-159D, 157A-158D, 189A-196D (grey group). Variegated color descriptions include both chimeric and non-chimeric expression.
Sequoia sempervirens exhibiting characteristics typical of redwoods grown
Table 3 highlights the distinctions between ‘Early Snow’ and its siblings. One clone from each of the siblings propagated in 2013 was measured for total height. Then all “B Zone” and “C Zone” secondary branches were counted on each siblings' main axis. After the count, a ratio of B to C Zone was established to determine the percentages of each. Since each invention's height varies, the total of each B and C Zones was divided into the height of the tree to determine the average height (centimeters) for B and C Zone branches respectively. The data tabulated below illustrates the different growing patterns discovered within B and C Zone secondary branches and was collected the Winter of 2015.
Findings in Table #3 demonstrate that ‘Early Snow’ produces nearly equal amounts of buds from B and C zones. This balanced distribution of variegated buds is thought to enhance ‘Early Snow’s visual appearance and marketablity when compaired to siblings: ‘Mosaic Delight’ and ‘Grand Mosaic’.
Table 4 presents a side by side comparison of the sibling varieties from the original cross experiments conducted in 1976. The siblings were grown in the same environmental conditions and exhibit the following similarities and differences.
