Morphological and molecular identification to secure cultivar maintenance and management of self-sterile Rubus arcticus

Background and Aims

Preservation of cultivar purity creates a particular challenge for plants that are self-incompatible, require insects for cross-pollination, and have easily germinating seeds and vigorously spreading rhizomes. As the fields must be planted with mixed populations, and a balance must be maintained between the cultivars to achieve effective pollination, methods for field monitoring of the relative density of different cultivars must be practical. Furthermore, a DNA-based method is needed for cultivar verification in the collections and outside of the growing season. The aim of this study was to develop both types of methods for Rubus arcticus (arctic bramble).

Methods

Morphological parameters were measured from six cultivars grown on three farms. Observations from the flowers and fruits included: petal and sepal number, flower diameter, arrangement of petals, size of calyx in relation to corolla, fruit weight, yield and soluble sugars. Observations from the leaves included: width and height of middle leaflet, shape of the base of terminal leaflet, shape of terminal leaflet, leaf margin serration and fingertip touch. The applicability of simple sequence repeat (SSR) or microsatellite DNA markers developed for red raspberry was tested on eight arctic bramble cultivars.

Key Results and Conclusions

Morphological and molecular identification methods were developed for R. arcticus. The best morphological characteristics were the length-to-width ratio of the middle leaflet and leaf margin serration. A particular characteristic, fingertip touch, was shown by electron microscopy to be related to the density and quality of the leaf hairs. Red raspberry SSR marker no. 126 proved to be applicable for differentiation of the eight arctic bramble cultivars tested. These identification methods are critical to secure the maintenance and management of R. arcticus. However, the challenges faced and approaches taken are equally applicable to other species with similar biology.     

Autumnal emergence of Anagrus wasps,egg parasitoids of Empoasca vitis,from grapevine leaves and their migration towards brambles

• 1 The Anagrus‘atomus’ parasitoid group (Hymenoptera: Mymaridae), associated with Empoasca vitis (Göthe) (Homoptera: Cicadellidae), overwinters on vegetation surrounding vineyards. The emergence of parasitoid adults from grapevine leaves in autumn was studied in north‐eastern Italy, both in relation to the E. vitis egg‐laying period and to the presence of leafhoppers overwintering as eggs on Rubus bushes.
• 2 Autumnal peaks of Anagrus captured using yellow sticky traps were observed first on grapevines and then on brambles. Parasitoid captures in vineyards were observed for more than 1 month after the last first‐instar nymphs of the grape leafhoppers were noticed. Two species belonging to the A. ‘atomus’ group, Anagrus atomus and Anagrus ustulatus, were captured both on grapevines and brambles.
• 3 Parasitoids of the A.‘atomus’ group can emerge from third‐generation grape leafhopper eggs in accordance with two different development time patterns (i.e. normal or delayed). Individuals with delayed emergence required up to 2.2‐fold more time to develop from an egg to adult than individuals with normal emergence. This meant that some parasitoid adults emerged in autumn from eggs of grape leafhopper laid in August.
• 4 A delayed emergence as a result of a slower development ensures that the A.‘atomus’ parasitoid group is synchronized with the egg‐laying of leafhoppers that overwinter as eggs on Rubus spp.
• 5 Consequently, leafhoppers overwintering as eggs on brambles play a key role in the ecology of the relationship between grape leafhoppers and the A.‘atomus’ parasitoid group.

     

Effect of lesion of nucleus robustus archistriatalis on call in bramble finch ( Fringilla montifringilla )

The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls. It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%–22.1% and 21.2%–24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%–25.8% on an average, and the step-up rate decrease 22.7% –24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.     

树莓种子原花青素的提取分离工艺研究

本文对树莓种子原花青素的提取及分离的工艺条件进行了研究和探讨。结果表明:水对原花青素的提取效果较好。用10倍于树莓种子重量的水(pH 8)于80℃提取三次,每次90 min,原花青素的提取效果最佳。提取液浓缩后,用NKA树脂吸附,当上样液pH值为7时,以50%乙醇溶液洗脱,分离出的原花青素含量最高,达23.66%,且产品得率也最大,达11.0%。     

An Evaluation of the Rust FungusGymnoconia nitensas a Potential Biological Control Agent for AlienRubusSpecies in Hawaii

The rust fungusGymnoconia nitensinfects blackberry (Rubus argutus) systemically in regions of the continental United States, producing bright yellow–orange masses of spores on newly developing floricanes during springtime. In tests to determine the suitability of this rust as a biological control agent forR. penetransin Hawaii, a species now thought to be conspecific withR. argutus,rooted cuttings of the Hawaiian plants were grown at North Carolina State University, inoculated, and observed. Other introduced weedyRubusspp. in Hawaii, includingR. ellipticus, R. rosifolius,andR. glaucus,as well as the two endemic speciesR. hawaiensisandR. macraei,also were inoculated. No species ofRubusare of commercial importance in Hawaii, but the protection of the native species, of whichR. macraeiis rare, was of utmost concern. The native Hawaiian species did not survive well in North Carolina in this study, however. Later availability of a plant pathogen containment laboratory in Hawaii enabled similar tests to be conducted at that facility. In addition to the above species,R. spectabilis(salmonberry), a species native to the Pacific Northwest with which the HawaiianRubusspp. are thought to share a common ancestor, was inoculated in Hawaii. Infection withG. nitensunder natural field conditions becomes apparent only when sporulation occurs on floricanes the second year following infection. However, experimental inoculation led to early responses of chlorotic leaf flecking and puckering, leaf and stem contortion, and stem gall formation, indicating the sensitivity ofR. penetrans(=R. argutus),R. hawaiensis,andR. macraeito this rust. Apparent systemic infection also resulted in sporulation on one plant ofR. macraei.Ability to attack the endemic species suggests thatG. nitenswould not be suitable for release in Hawaii as a biological control agent, at least on the islands with populations of the native species.     

Occurrence of Peronospora sparsa (P. rubi) on cultivated and wild Rubus species in Finland and Sweden

An outbreak of a dryberry disease caused by Peronospora sparsa (syn. P. rubi) occurred in plantations of arctic bramble (Rubus arcticus subsp. arcticus) in Finland in the middle of 1990s. The disease persists and is most severe in cool and rainy summers. The disease has not been encountered in northern Sweden where cultivars (R. arcticus nothosubsp. stellarcticus) different from those in Finland are used. The occurrence of P. sparsa in wild Rubus spp. is virtually unknown in both areas and it is not known whether they constitute a potential infection source. Therefore, the aim of this study was to investigate the occurrence of P. sparsa on wild Rubus spp. growing in the vicinity of cultivations of arctic bramble. Symptomatic plants were sampled in 1997–1999. P. sparsa was detected using a light microscope, preceded by incubation of the sample in vitro if necessary, and by a polymerase chain reaction (PCR) based method. Plants of cultivated R. arcticus subsp. arcticus were commonly infected by P. sparsa in Finland. P. sparsa was also found on the cultivated R. arcticus nothosubsp. stellarcticus in Finland and Sweden. However, the infected plants of the cultivars of nothosubsp. stellarcticus seemed to be much less damaged than the cultivars of subsp. arcticus. Plants infected with P. sparsa were found in the populations of wild R. arcticus subsp. arcticus in both countries, and in cloudberry (R. chamaemorus) in natural habitats in Finland. In addition, P. sparsa was detected on specimens of R. arcticus subsp. arcticus (collected in 1966–1985) and R. chamaemorus (collected in 1899–1981) in Finnish herbaria. The samples of R. idaeus and R. saxatilis collected from the field in this study or investigated in the herbaria were not infected with P. sparsa. These data show that P. sparsa has not recently invaded Finland but has become an economically significant pathogen during the rapid expansion of cultivation of the apparently sensitive clones of arctic bramble.     

Effect of lesion of nucleus robustus archistriatalis on call in bramble finch (Fringilla montifringilla)

The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls. It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%–22.1% and 21.2%–24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%–25.8% on an average, and the step-up rate decrease 22.7% –24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.     

Effect of lesion of nucleus robustus archistriatalis on call in bramble finch (Fringilla montifringilla)

The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls. It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows ri