Cold hardiness of southern-adapted blueberry (Vaccinium × hybrid) genotypes and the potential for their use in northern-adapted blueberry breeding

Twelve southern-adapted blueberry genotypes, both southern highbush ( Vaccinium corymbosum L. introgressed with 2x V. darrowi Camp) and rabbiteye ( V. ashei Reade), were evaluated for bud development using a morphological scale and for mid-winter cold hardiness using a shoot freezing assay. The winter of 2006–2007 was particularly warm producing higher bud development scores for several of the genotypes and an apparent decrease of cold hardiness. Significant differences in LT₅₀ values (treatments causing 50% bud mortality) were observed among the genotypes in both years, with a significant clone × year interaction. The greatest range in LT₅₀ values occurred in 2007, when values ranged from −11.9°C for 'Millennia' to −25.5°C for 'Reveille', two southern highbush cultivars. Results suggest that germplasm selected in North Carolina might typically have sufficient cold hardiness to be used without concern as parental material in the development of blueberry germplasm with northern adaptation. Other more southern germplasm was generally less hardy and, if utilized as parental material, the resulting progeny would require greater scrutiny with regard to cold hardiness.     

蓝莓适生环境与栽培技术研究

结合蓝莓不同品种的生物学特性,阐述了蓝莓的适生环境,包括适宜的气候条件、土壤环境和地形和地貌。从育苗、栽植、修剪和水肥管理等方面提出了比较合理的栽培技术措施。并探讨了存在的问题及发展趋势。     

Artificial infection of Vaccinium vitis-idaea L. and defence responses to Exobasidium species

An inoculation method for Exobasidium splendidum and Exobasidium vaccinii was developed on the dwarf shrub Vaccinium vitis-idaea. Using inoculated ramets, we investigated whether there are differences between V. vitis-idaea populations in the susceptibility to Exobasidium infections and whether the defence reaction of V. vitis-idaea is visible at a molecular level. Sixteen V. vitis-idaea clones from four populations were propagated in tissue cultures and the ramets were inoculated with E. splendidum or E. vaccinii fungi. The expression of three flavonoid biosynthetic genes (chalcone synthase, dihydroflavonol 4-reductase and anthocyanidin synthase) and the accumulation of flavonoids and hydroxycinnamic acids were determined in response to E. splendidum infection. A pathogenesis-related (PR 4) gene was isolated and its expression was studied in host ramet leaves. To our knowledge, this was the first successful artificial infection reported with E. splendidum. Disease frequencies of the inoculated ramets were between 32% and 47% for E. splendidum and 33% for E. vaccinii, but below 10% in uninoculated control ramets. There were no differences in disease frequencies between V. vitis-idaea populations. Both symptomatic leaves and healthy leaves of diseased ramets showed activation of flavonoid biosynthesis at the gene level, whereas expression of PR 4 was observed only in symptomatic leaves. The increase of flavonoid biosynthesis in healthy leaves of diseased ramets may represent a general response to stress or a role in defence against the pathogen E. splendidium. Ability of V. vitis-idaea to defend chemically against Exobasidium fungi and the heterogeneity of genotypes, age, size, and growth rates in host plant populations might be reasons for the low infection incidence of Exobasidia in nature.     

Laboratory and field susceptibility of blueberry spanworm (Lepidoptera: Geometridae) to conventional and reduced-risk insecticides

Blueberry spanworm (Itame argillacearia Packard) is a key insect defoliator of wild blueberry, an important crop in north-eastern North America. We evaluated the susceptibility of blueberry spanworm to several reduced-risk insecticides in laboratory and field experiments. Two populations from two Canadian provinces were studied in the laboratory. Both were highly susceptible to flubendiamide, spinetoram and deltamethrin, although there were inter-population differences, and flubendiamide was slower acting. Flubendiamide, spinosad, spinetoram, and methoxyfenozide demonstrated good suppression of economically damaging populations of blueberry spanworm larvae in the field.     

野生笃斯越桔适生生境研究

[目的]考察大兴安岭野生笃斯越桔的适宜生境。[方法]根据大兴安岭野生笃斯越桔生物学特性及生境条件,利用数量化Ⅰ方法,通过对影响野生笃斯越桔株高生长和平均单株产量的8个环境因子的分析,研究野生笃斯越桔的适宜生境。[结果]影响野生笃斯越桔株高生长的主导因子依次为土壤类型、全氮含量、pH值、含水量、有机质含量、A层厚度;影响野生笃斯越桔平均单株产量的主导因子依次为土壤类型、全氮含量、有机质含量、pH值、含水量、A层厚度。样地聚类结果表明,研究区域样地可分为3种类型,以样地平均株高及平均单株产量作为笃斯越桔适宜生境衡量指标,表明第1类样地的生境条件最适宜。[结论]该研究为笃斯越桔模拟自然栽培技术提供了重要理论参考。     

兔眼蓝莓灿烂的快繁技术优化

对兔眼蓝莓灿烂组培苗的增殖、生根及瓶外驯化技术的研究并优化.经过试验,确定灿烂最佳增殖培养基为wpm＋1.5mg/LZT＋0.5mg/L6-BA;最佳生根培基为wpm＋1.5mg/L＋0.2g/L活性炭,并进行7d的暗室处理后,生根率达到80％;最适炼苗基质为腐殖土∶园土=3∶1,保持湿度84％,温度35℃,组培苗成活率达到85％.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Quality of Highbush Blueberry (Vaccinium corymbosum L.) and Bilberry (Vaccinium myrtillus L.) Jam

ABSTRACT

Jam from wild bilberries and from the blueberry culti vars ‘Bluecrop’ and ‘Berkeley’ were analyzed by means of sensory profiling and by instrumental measurement of anthocyanins, color, pH and soluble solids. The study shows that bilberry jam has more “bluish black color,” compared to a more “reddish-blue color” and “glossy” surface of the jam from cultivated blueberries. Bilberry jam was less “smooth” and higher in “viscosity” and “berry density” as well as less distinct in “flavor of flowers and fruits,” while the “blueberry flavor and odor” were more distinct in the bilberry jam than that made of highbush blueberries. Analysis of color by means of sensory hue and instrumental a Hunter lab corresponded well, as did saturation measured by the sensory method and chroma instrumentally measured.     

Cultural Variation and Mycorrhizal Status of Blueberry Plants in NW Oregon Commercial Production Fields

ABSTRACT

Ericoid mycorrhizal fungi (EMF) form symbiotic relationships with roots of blueberry plants providing increased access to nutrients from fertilizers and soil. In August of 2001, we sampled 55 fields in Oregon to assess the mycorrhizal status of blueberry plants under production conditions and to determine whether any relationships exist between field characteristics, root distribution, soil characteristics and level of colonization by mycorrhizal fungi. Variation in measured soil characteristics, root type, root distribution and mycorrhizal colonization occurred with cultivar, field age, bed type, rate of nitrogen fertilization, irrigation type, and mulch. Root biomass was lower in the upper 15 cm of soil compared to 15-30 cm depth. Distribution of roots between the two sampled depths varied significantly with field age, nitrogen fertilization rate, and the time of 50% harvest for the different cultivars sampled. Root length was generally greatest in the upper 15 cm of the soil than at the 15-30 cm depth. Root colonization by ericoid mycorrhizal fungi (EMF) ranged from 0.5 to 44% of total root length with higher colonization generally occurring in the upper 15 cm of the soil where the majority of smaller, finer roots were found. Colonization generally increased with increasing plant age. In young plants the highest levels of colonization were found in roots from the upper 15 cm of soil while in older plants the highest levels of colonization were found in roots at the 15-30 cm depth. Colonization of roots by EMF in the upper 15 cm of the soil tended to decrease with increasing N fertilization rate, while root colonization at the 15-30 cm depth was unaffected by rate of N fertilization. Roots on cultivars that fruited early in the season tended to have higher levels of colonization than cultivars that fruited later in the growing season. Root biomass and root length were negatively correlated with soil pH and available Ca in soil, while root colonization by EMF was negatively correlated with ammonium levels in the soil. Differences in soil characteristics, root type and distribution, and mycorrhizal colonization found in this study need to be investigated in terms of production efficiency of blueberry in Oregon.