Autumn Gold Research Articles

Autumn gold in Beijing - EMC Beijing 2017

Line Eight of the marvelous Beijing Subway (地铁or, literally, “Earth Iron”) takes riders along the northern extension of an imaginary line that connects the Forbidden City in the center of the city to the vast complex built to host the 2008 Olympics. We enjoyed a few days of “Golden Autumn” in Beijing, which was just revealing the golden hues of the many gingko, willow and locust trees that thrive around the city.

Seven Ulmus minor clones tolerant to Ophiostoma novo-ulmi registered as forest reproductive material in Spain

Abstract: The Spanish elm programme began in 1986 in response to the devastating impact of Dutch elm disease on natural elm stands and urban trees. Its main objectives were to conserve remaining genetic resources and select and breed tolerant native elm genotypes. After 27 years of work conducting susceptibility trials on thousands of elm genotypes, the first seven tolerant Ulmus minor trees are now being registered by the Spanish Environmental Administration. This paper presents the results of the susceptibility tests on these clones and their distinctive genetic, morphological and phenological features. In all susceptibility trials the commercial “Sapporo Autumn Gold” clone, which is highly tolerant to O. novo-ulmi, was used as a control. The registered clones were named “Ademuz”, “Dehesa de la Villa”, “Majadahonda”, “Toledo”, “Dehesa de Amaniel”, “Retiro” and “Fuente Umbria”. The most tolerant clone was “Dehesa de Amaniel”, as its wilting values were below 5% during the two consecutive inoculation trials performed in Madrid. “Fuente Umbria”, tested over four consecutive years in Guadalajara and Palencia, was the Spanish clone with the most reliable tolerance level to O. novo-ulmi. The “Ademuz” and “Majadahonda” clones had the highest ornamental scores and are promising trees for use in urban environments and tree breeding for ornamental quality. These two genotypes showed a later bud burst phenology than the other U. minor clones, demonstrating suitability to areas with late frost events. The Spanish programme aims to substantially increase the range of tolerant native elms through new selections and crossings to gain a better understanding of the genetic basis of resistance.

Comparison of commercial elm cultivars and promising unreleased Dutch clones for resistance to Ophiostoma novo-ulmi

Elms, and especially Ulmus × hollandica have been dominant and very much appreciated trees in cities and rural landscape for centuries in the Netherlands. As a result of two Dutch Elm Disease (DED) epidemics in the 20th century these trees largely disappeared from the landscape. Despite the introduction of new cultivars with increased levels of DED-resistance, by the end of the 20th century the elm had disappeared from the top 20 list of trees produced by Dutch nurseries. New cultivars with increased resistance to DED are used to a limited extent only. Apparently the lasting problems with DED in old cultivars has led to a lack of confidence in the resistance of these latest released cultivars among urban foresters and landscape managers. This paper reports on a study that aims at restoring the position of the elm as a street tree in the Netherlands by providing information on resistance to O. novo-ulmi causing DED of the currently available cultivars. All elm cultivars currently on the Dutch market were compared in an inoculation test. In 2007 a field experiment of 18 cultivars, one species and 10 non-released clones from the Dutch elm breeding program was established. Two cultivars were used as reference clones: “Commelin” (relatively susceptible) and “Lobel” (relatively resistant). In 2008 and 2009 the elms were stem-inoculated with Ophiostoma novo-ulmi and disease development was assessed throughout the summer and the following year. Clear differences in resistance to O. novo-ulmi were found between the cultivars, with “Columella”, “Sapporo Autumn Gold”’ and “Rebella” being highly resistant and significantly different from “Lobel” and “Regal”, “Urban”, “Belgica”, “Den Haag” and the U. laevis seedlings being the most susceptible and comparable to “Commelin”. The non-released clones performed comparable to “Lobel’”or even better. The ranking of the cultivars based on their level of resistance to O. novo-ulmi in this field test corresponds well with experience in urban green practice. Our conclusion is that there is a wide range of cultivars available with a good to excellent level of resistance. The available cultivars have a broad genetic base due to different parentage and use of exotic germplasm in the crossings. This broad genetic background may contribute to the stability of resistance in case new forms of the disease appear. The non-released clones performed well compared to the released cultivars and give good opportunities to further broaden the current range of cultivars on the Dutch and European market.

Association between photosynthesis and contrasting features of minor veins in leaves of summer annuals loading phloem via symplastic versus apoplastic routes

Foliar vascular anatomy and photosynthesis were evaluated for a number of summer annual species that either load sugars into the phloem via a symplastic route (Cucumis sativus L. cv. Straight Eight; Cucurbita pepo L. cv. Italian Zucchini Romanesco; Citrullus lanatus L. cv. Faerie Hybrid; Cucurbita pepo L. cv. Autumn Gold) or an apoplastic route (Nicotiana tabacum L.; Solanum lycopersicum L. cv. Brandywine; Gossypium hirsutum L.; Helianthus annuus L. cv. Soraya), as well as winter annual apoplastic loaders (Spinacia oleracea L. cv. Giant Nobel; Arabidopsis thaliana (L.) Heynhold Col-0, Swedish and Italian ecotypes). For all summer annuals, minor vein cross-sectional xylem area and tracheid number as well as the ratio of phloem loading cells to phloem sieve elements, each when normalized for foliar vein density (VD), was correlated with photosynthesis. These links presumably reflect (1) the xylem's role in providing water to meet foliar transpirational demand supporting photosynthesis and (2) the importance of the driving force of phloem loading as well as the cross-sectional area for phloem sap flux to match foliar photosynthate production. While photosynthesis correlated with the product of VD and cross-sectional phloem cell area among symplastic loaders, photosynthesis correlated with the product of VD and phloem cell number per vein among summer annual apoplastic loaders. Phloem cell size has thus apparently been a target of selection among symplastic loaders (where loading depends on enzyme concentration within loading cells) versus phloem cell number among apoplastic loaders (where loading depends on membrane transporter numbers).

Effects of 1‐MCP applied postharvest on epicuticular wax of apples (Malus domestica Borkh.) during storage

AbstractBACKGROUND: Certain apple cultivars develop a greasy feel when overripe. Treating fruits with the ripening inhibitor 1‐methylcyclopropene (1‐MCP, SmartFresh™) reduces fruit greasiness. This study examines the nature of this phenomenon. ‘Royal Gala’ apples were treated with 1‐MCP at 1.0 µl L−1 following harvest. Periodically, during storage at − 1 °C for up to 6 months, fruits were evaluated for internal ethylene concentration, fruit epicuticular wax morphology (using scanning electron microscopy) and non‐polar organic solvent‐extractable (NPOSE) wax constituents of the cuticle (using gas chromatography/mass spectrometry).RESULTS: In 2004, 1‐MCP strongly inhibited internal ethylene production; however, total weight of NPOSE wax during storage was unaffected by treatment. In 2005, several wax constituents present in both ‘Autumn Gold’ and ‘Royal Gala’ showed differences during storage. In 2006, cuticular wax constituents comprising 80% of the total from ‘Royal Gala’ showed no treatment differences. Although several minor constituents did exhibit differences within treatment and sampling date, these did not appear sufficient to cause the subtle differences in surface wax morphology.CONCLUSION: 1‐MCP strongly inhibited ethylene production and delayed development of certain wax constituents thought responsible for fruit greasiness during cold storage. Subtle differences in surface wax morphology appeared unrelated to wax production. Published in 2008 by John Wiley & Sons, Ltd.

Susceptibility of 32 Elm Species and Hybrids (<I>Ulmus</I> spp.) to the Elm Leaf Beetle (Coleoptera: Chrysomelidae) Under Field Conditions in Arizona

We evaluated elm leaf beetle, Pyrhalta luteola (Müller) (Coleoptera: Chrysomelidae), defoliation of 32 elm species or hybrids (taxa) established under field conditions in Holbrook, AZ. Percentage of defoliation, number of eggs, and number of larvae were estimated on randomly selected 15-cm shoot lengths annually in July, from 1996 to 2001. The following nine taxa consistently sustained 15-46% mean overall defoliation: 1) Siberian elm, U. pumila L.; 2) 'Dropmore' elm, U. pumila; 3) 'Camperdownii' elm, U. glabra Huds.; 4) 'Regal' elm, U. glabra x U. carpinifolia Gledisch x U. pumila); 5) 'Sapporo Autumn Gold' elm (U. pumila x U. japonica Sang.); 6) 'New Horizon' elm (U. pumila x U. japonica); 7) 'Charisma' elm [(U. japonica x U. wilsoniana Schneid.) x (U. japonica x U. pumila)]; 8) 'W2115-1' elm (U. parvifolia Jacq. x U. procera Salisb.); and 9) 'Homestead' elm [(U. hollandica Mill. x U. carpinifolia) x (U. pumila-racemosa Dieck x U. carpinifolia)]. Percentage of defoliation was significantly low on four Chinese elm (U. parvifolia) cultivars ('Allee', 'Athena', 'Glory'/lace bark, and 'Kings Choice'). Percentage of defoliation was also low on seven Asian elms (including U. chemnoui Cheng, U. bergmaniana Sneid., U. szechuanica Fang, and species of the U. davidiana Planch. complex [U. davidiana, U. japonica, U. wilsoniana, and U. propinqua Koidz.]) and the American elm (U. americana L.) 'Valley Forge'. Percentage of defoliation and the number of eggs or larvae per plant were highly correlated. The results of this study are generally consistent with results of past laboratory screening trials.

New late-season navel orange varieties evaluated for quality characteristics

New early- and late-maturing navel orange varieties have expanded the navel orange season for California's domestic and export fresh-fruit market. For 5 years, we evaluated the fruit-quality characteristics of purported late-season varieties imported from Australia to determine whether they have any advantages over Lane Late, the first late-season navel orange imported from Australia and grown in California. Of the six varieties evaluated, Autumn Gold, Barnfield, Chislet, Powell and Lane Late had late-maturing characteristics, but none of these varieties stood out as having the latest maturing fruit for all traits associated with maturity at all nine locations studied. For certain locations, sample dates and years, there were significant differences among the varieties for quality traits associated with maturity, such as solids-to-acid ratio, percentage acidity and puncture resistance, but these differences varied depending upon location.

Stegophora ulmea

<i>Stegophora ulmea</i>

Adaptation and Market Potential of Jack o' lantern and Miniature Pumpkin Cultivars in Eastern North Carolina

In 1998 and 1999, a total of 27 large-fruited and 15 miniature-fruited pumpkin (Cucurbita pepo) cultivars were evaluated for adaptation to eastern North Carolina grow- ing conditions. Test categories were yield (fruit number and weight); fruit characteristics (shape, rind and stem attributes); and susceptibility to edema (wart-like growths on fruit exterior), foliar diseases, preharvest and postharvest fruit decay, and viruses. Yields of large pumpkins ranged from over 3,200 fruit/acre (7,907 fruit/ha) for `SVT 4613367', `Autumn Gold', and `Gold Standard' to less than 1,000 fruit/acre (2,471 fruit/ha) for `Gold Rush' and `Progold 200'. For miniature pumpkins, over 33,000 fruit/acre (81,542 fruit/ha) were produced by `Touch of Autumn', `Lil' Pump- ke-mon', and `HMX 5682', whereas `Mystic' and `Progold 100' produced less than 7,000 fruit/acre (17,297 fruit/ha). `Gold Rush', `Howden', and `Progold 510' (large), and `EXT 4612297', `Lil' Goblin', and `Lil' Ironsides' (miniature) appeared the most susceptible to foliar diseases. Preharvest fruit decay ranged from 0% for `Howden' and `EXT 4612297' to over 20% for `Lil' Goblin', `Jumping Jack', `Peek-A-Boo', and `Tom Fox'. Virus incidence on fruit and foliage was low on virus-resistant cultivars ('SVT 4613367' and `EXT 4612297'), and ranged from 4% to 74% for nontransgenic cultivars. Virus incidence and/or severity on foliage and fruit were not related. `Early Autumn' (large) and `Touch of Autumn' (miniature) were the most prone to edema. `Aspen' and `Magic Lantern' (large) and `Baby Pam', `Lil' Goblin', and `Spooktacular' (miniature) were the most susceptible to postharvest fruit decay. Fruit characteristics are discussed in relation to marketability and possible consumer appeal to pumpkins.

Comparative study of rooting of leaf-bud and straight softwood elm cuttings

Parallel propagation tests of nine elm taxa - 6 species (Ulmus americana L., U. chenmoui Cheng, U. japonica (R) Sarg., U. laciniata (Tr) Mayr, U. laevis Pall. and U. parvifolia Jacq), 2 clones (U. 'Regal', U. 'Sapporo Autumn Gold') and 1 hybrid (U. pumila x japonica), by leaf bud cuttings and standard straignt softwood showed the results which point to the possibility of wider application of leaf bud cuttings. In some elm taxa, leaf bud cuttings can be the main method of propagation, and it can be used as an additional method in other taxa, because the seasonal timing is extended compared to standard cuttings.

Growth and Mortality of Dogwood Cultivars in Alabama

Abstract An open-field evaluation of 38 dogwood (Cornus) cultivars was conducted in central Alabama from May 1996 to March 1998. Mortality increased dramatically in giant dogwood (C. controversa Hemsl.), kousa dogwood cultivars (C. kousa Hance), and kousa x flowering dogwood hybrids (C. kousa x florida) from August 1996 to August 1997. Little mortality was observed for the flowering dogwood selections (C. florida L.) during this same period. Further characterization, based on height and stem diameter increases, was conducted on 23 flowering dogwood cultivars. Greatest average annual height and stem diameter increases for cultivars with white bracts and green foliage were observed in ‘Cloud 9’, ‘Fragrant Cloud’, ‘Ozark Spring’, ‘Springtime’, ‘Weaver’, ‘Welch Bay Beauty’, and ‘World's Fair’. Lowest average annual height and stem diameter increases occurred with ‘Autumn Gold’ and Wonderberry®. Among the selections with red or pink bracts and green foliage, ‘Stoke's Pink’ and ‘Welch's Junior Miss’ had greater annual average increases in height and stem diameter than ‘Purple Glory’. Annual average increases in height and final heights were similar among all cultivars with variegated foliage, with ‘First lady’ showing the greatest annual average increase in stem diameter and final stem diameter.

Comparing Gompertz and Richards Functions to Estimate Freezing Injury in Rhododendron Using Electrolyte Leakage

Seasonal patterns in freezing tolerance of five Rhododendron cultivars that vary in feezing tolerance were estimated. Electrolyte leakage was used, and raw leakage data were transformed to percent leakage, percent injury, and percent adjusted injury. These data were compared with visual estimates of injury. Percent adjusted injury was highly correlated (0.753) to visual estimates. Two asymmetric sigmoid functions—Richards and Gompertz—were fitted to the seasonal percent adjusted injury data for all cultivars. Two quantitative measures of leaf freezing tolerance—Lt50 and Tmax (temperature at maximum rate of injury)—were estimated from the fitted sigmoidal curves. When compared to the General Linear Model, the Gompertz function had a better fit (lower mean error sum of squares) than Richards function. Correlation analysis of all freezing tolerance estimates made by Gompertz and Richards functions with visual LT50 revealed similar closeness (0.77 to 0.79). However, the Gompertz function and Tmax were selected as the criteria for comparing relative freezing tolerance among cultivars due to the better data fitting of Gompertz function (than Richards) and more descriptive physiological representation of Tmax (than LT50). Based on the Tmax (°C) values at maximum cold acclimation of respective cultivars, we ranked `Autumn Gold' and `Grumpy Yellow' in the relatively tender group, `Vulcan's Flame' in intermediate group, and `Chionoides' and `Roseum Elegans' in the hardy group. These relative rankings are consistent with midwinter bud hardiness values reported by nurseries.

Performance of Cornus florida L. Selections in the Southeast

In a full-sun Auburn, Ala., field study, 23 cultivars and 1 forma of Cornus florida L. were evaluated for growth from 1994 to 1996 and bract characteristics in Spring 1996. The selections were divided into three groups for analyses: 1) white bracted with green foliage, 2) red or pink bracted with green foliage, and 3) variegated foliage. Among the white bracted cultivars with green foliage, `Weaver' and `Welch Bay Beauty' had the greatest height and stem diameter increases, `Autumn Gold' the least. `Cloud 9' had the largest bract size. `Welch's Junior Miss' had the greatest height increase, while `Stokes' Pink' had the greatest stem diameter increase for the red or pink bracted cultivars with green foliage, and f. rubra the least. `Red Beauty' had the largest bract size. There were no differences among the variegated cultivars in height increase or bract size; however, `First Lady' had the greatest stem diameter increase.

Seasonal Fluctuations in Cold Hardiness and Protein Profiles of Five Rhododendron Cultivars

A time-course study was conducted to characterize seasonal patterns of cold hardiness (CH) and protein profiles in the leaf tissue of five Rhododendron cultivars (`Grumpy Yellow', `Vulcan's Flame', `Autumn Gold', `Chionoides', and `Roseum Elegans'). Leaf samples were collected monthly (starting in mid September) and leaf discs were subjected to controlled freezing and thawing regimes. CH (LT50 defined as temperature causing 50% injury) was assessed by electrolyte leakage and visual observations. Data indicate that cultivars varied in their CH in nonacclimated state and in their ability to cold acclimate. Results obtained in September showed `Grumpy Yellow' to be least hardy (about –3°C) and `Roseum Elegans' to be most hardy (about –7°C). All cultivars exhibited successive increases in CH during fall and winter. Maximum CH in all cultivars occurred by December/January with `Chionoides' being most hardy (about –31°C) while `Grumpy Yellow' was least hardy (about –20°C). LT50 based on electrolyte leakage was highly correlated with visual rating. Seasonal changes of protein profiles and relationship of specific stress proteins to cultivars' CH and cold acclimation ability are discussed.

302 POLLINATION AND FRUITSET PATTERNS OF FIELD-GROWN PUMPKINS

Investigations of varietal differences in pumpkin flowering and fruitset patterns were initiated in response to reports of poor fruitset by NYS growers. In addition, pollination requirements for marketable fruit were explored in one cultivar. Flowering date, fruitset, and fruit characteristics were recorded for 2 consecutive years in a RCBD of six popular Cucurbita pepo cultivars (Wizard, Happy Jack, Autumn Gold, Ghost Rider, Howden and Baby Bear). On average, female blossoms opened 38 days after 3-wk-old seedlings were transplanted into the field. Flowering period lasted for 3 to 4 weeks. No consistent pattern was found in female flower production nor fruitset until the last week when significant declines occurred. Each blossom only opens for one day and typically closes between 10 am and noon, limiting pollination opportunities. H and-pollination of Wizard' with various dilutions of pollen revealed that a minimum of approximately 2000 grains of pollen is necessary for fruitset. Removal of 66-75% of the stigmatic surfaces did not affect seed number or their location in the fruit, nor fruit shape or size. Fruit size was not correlated with seed number, although no fruit developed with less than 100 seed.

First Snow

of this earth." The father seems as rootless as Walking John Gay, whose words bring back to mind the river of earth metaphor: "They's a world of dirt flowed under my feet. I never crawled when I was a baby. Just riz up and walked at ten months. I'm a-mind to see every living hill against I die." It is the father, and thus others in his train, who float on the surface of this river, knowing least the answer to Brother Sim Mobberly's question: Oh, my children, where air we going on this mighty river of earth, a-borning, begetting, and a-dying-the living and the dead riding the waters? Where air it sweeping us? Perhaps a little child, a nameless seven-year-old boy, shall lead them. Or perhaps a poet. It is likely they are the same. Surely the narrator of the poem, "River of Earth," is the child of vision, the naive observer, the innocent seer of the novel. The boy has a yearning for poetry, "music not set to notes." When asked what he would do with a bagful of money, he says, "I'd buy me a broadside off the peddle-woman.' Here again in the novel we find the frustrated visionary , the one who knows, modestly, "least or all," what he will never understand. And so he turns to poetry. Poet and child are one. They are James Still. This is today's book, and tomorrow's. Silver Hills The first snowfall silvers the hills on upper reaches and turns each simple tree into delicate filigree. The hilltop becomes a frosted decoration each pine a Christmas tree. The autumn gold transmutes to winter silver. -David F. Moore First Snow Walnut and amber wrap me, rocking, relaxed in the scent of yeast bread, rising. Through the cold gleam of glass I watch black stripped tree arms cradle snow, iced, in winter silence. -Margaret D. Kirkland ...

‘Prairie Shade’ Elm

Abstract Since the urban population of American elms (Ulmus americana L.) was ravaged by Dutch elm disease fungus [Ceratocystis ulmi Buism. (C. Moreau)], attention has focused on the development of disease resistant elm hybrids. The cultivars ‘Sapporo Autumn Gold’, ‘Urban’, and ‘Regal’ are highly resistant to Dutch elm disease (7, 8, 9); however, they are extremely susceptible to the elm leaf beetle, (Pyrrhalta luteola Muller), because the susceptible Siberian elm Ulmus pumila L.) is a common parent (10). On the other hand, Ulmus parvifolia Jacq. (syn. U. sempervirens), U. chinensis Pers., sometimes listed incorrectly as the lacebark elm (syn. leatherleaf elm, Chinese elm) is highly resistant to Dutch elm disease and the elm leaf beetle (1, 2, 4, 10). Lacebark elm is native to central China, Japan, and Korea, is drought tolerant, and withstands the severe conditions often associated with urban sites (10). Like most other members of the genus Ulmus, lacebark elm is propagated by seed collected in the fall; however, Schopmeyer (6) indicated that less than 50% of the seeds are viable, and only 5% to 12% of the viable seed sown can be expected to produce saleable trees. Four asexually produced cultivars, ‘Sempervirens’, ‘Drake’, ‘True Green’, and ‘Dynasty’ (5), currently sold provide improved consistency and quality.

Barrier Zone Formation as a Resistance Mechanism of Elms to Dutch Elm Disease

Host responses of elms susceptible and resistant to Dutch elm disease were histologically examined. In a time course study the susceptible elm clone Ulmus × hollandica 'Belgica' and U. × hollandica '390', a clone which shows a high degree of resistance to non-aggressive isolates and a moderate degree of resistance to aggressive isolates of Ophiostoma ulmi, were inoculated in twig or trunk with either an aggressive or a non-aggressive isolate of O. ulmi. For purposes of comparison, the susceptible elm U. americana and the more resistant clones U. × hollandica 'Groeneveld', U. 'Lobel' and U. 'Sapporo Autumn Gold' were included. Depending on clone-isolate compatibility, infected twigs reacted by a walling off process, by barrier zone formation, or failed to resist the infection and died. Trees inoculated into the trunk reacted comparably but in the case of a compatible combination they always formed a barrier zone and the cambium never died in the year of inoculation.

Autumn's Red and Gold: Fire

Autumn's Red and Gold: Fire