Incompatibility alleles in Corylus avellana L. cultivars

Summary Pollen-stigma compatibility relationships are reported for 55 filbert cultivars (cvs) (Corylus avellana L.). A total of 11 S-alleles have been identified amongst 36 cvs for which one or both S-alleles have been established. For the 20 cvs with only one known allele and the 17 for which neither allele have been identified further information is provided as to which alleles can be excluded as possibilities.Oregon Agricultural Experiment Station Technical Paper No. 4985. Corvallis, Oregon 97331     

Dominance relationships among S-alleles in Corylus avellana L.

Summary Pollen-stigma compatibility relationship were studied in 50 cultivars and more than 800 seedlings of the European hazelnut (Corylus avellana L.). A total of 22 unique S-alleles have been identified. Dominance relationships in 75 of the possible 231 pairs of alleles have been determined in both pistil and pollen. In the pistil, all alleles exhibited independent action, whereas in the pollen, alleles exhibited either dominance or codominance. The dominance relationship was linear with 7 levels of dominance.Oregon Agricultural Experiment Station Technical Paper No. 8542     

Revised dominance hierarchy for S-alleles in Corylus avellana L.

Pollen-stigma compatibility was studied in cultivars and more than 1800 seedlings of the European hazelnut (Corylus avellana L). Four new S-alleles were identified, bringing the total to 25 unique alleles within C. avellana. The new alleles are the recessive alleles in ‘Tonda di Giffoni’ and ‘Segorbe’ (S₂₃), in ‘Neue Riesennuss’ (S₂₅), in ‘Gasaway’ (S₂₆), and a dominant allele in a seedling of Turkish origin (S₂₄). Dominance relationships in 233 of the possible 300 pairs of alleles were determined in both pistil and pollen. All alleles exhibited independent action in the pistil, whereas in the pollen either dominance or codominance was exhibited. The dominance hierarchy of alleles in the pollen was revised in light of the new information obtained. All 25 alleles have been assigned to a level in the hierarchy that is linear and now has eight levels. S₆ and S₉ were reassigned to lower levels in the hierarchy. Thirteen of the alleles are on the level of S₁, while S₄, S₆, S₁₁, and S₂₃ occupy unique positions in the hierarchy. Improved pollen tester clones were identified for several S-alleles. The alleles in 55 cultivars were determined. The alleles identified in ‘DuChilly’ (S₁₀ S₁₄) did not agree with previous reports. Four cultivars have the same alleles as ‘Römische Nuss’ (S₁₀ S₁₈) and are morphologically indistinguishable from it: ‘Frutto-grosso’, ‘Istarski Okrogloplodna’, ‘Payrone’, and ‘Romai’. ‘Belle di Giubilino’ and ‘Tonda di Biglini’ are both S₁ S₁₀ and appear to be synonyms for the same cultivar.     

Pentose phosphate metabolism during dormancy breakage in Corylus avellana L.

Commercially obtained fruits of Corylus avellana exhibit the characteristic loss of dormancy of this seed following chilling under moist conditions. The activities of cytosolic and organellar enzymes of pentose phosphate pathway in cotyledonary tissue were assayed throughout stratification and over a similar period in damp vermiculite at 20° C. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconic acid dehydrogenase (6PGDH) were both found in cytosolic extracts in all treatments; only 6PGDH was present in the organellar fraction.The enzyme activities monitored in seeds at 20° C remained relatively constant over the course of the investigation except in the case of cytosolic 6PGDH where it is suggested an inhibitor of the enzyme accumulated. This inhibitor was removed by the partial purification procedure. Increases in the activities of the enzymes occurred during stratification, the major increase coinciding exactly with dormancy breakage but prior to the initiation of germination. The marked increase in G6PDH and 6PGDH concurrent with the change in germination potential of the chilled seed may have considerable biochemical significance in breaking down the dormant state.Abbreviations G6P glucose-6-phosphate - G6PDH glucose-6 phosphate dehydrogenase - NADP nicotinamide adenine dinucleotide phosphate - 6 PGDH 6-phosphogluconic acid dehydrogenase - PPP pentose phosphate pathway     

Lobeline production by hairy root culture of Lobelia inflata L.

Hairy roots were obtained following inoculation of the stems of Lobelia inflata L. with Agrobacterium rhizogenes strain ATCC 15834. These hairy roots contained agropine and mannopine. In addition, lobeline was detected by HPLC and confirmed by mass spectrometry. Various media were tested for the growth of hairy roots as well as for the content of lobeline in hairy roots. The growth rate of hairy roots cultured in Nitsch and Nitsch's medium was approximately one third of those cultured in other media. The lobeline content of hairy roots (18–54 g/g dry weight) cultured in these media was the same order of magnitude compared with that of roots of L. inflata (24 g/g dry weight) cultivated in pots. The hairy roots cultured in Nitsch and Nitsch's medium were morphologically different from those cultured in other media.Abbreviations MS medium Murashige and Skoog's medium - 1/2 MS medium one-half strength of the standard Murashige and Skoog's medium - B5 medium Gamborg's B5 medium - NN medium Nitsch and Nitsch's medium - FW fresh weight - DW dry weight     

Nondormant mutants in a temperate tree species,Corylus avellana L.

Summary Nondormant mutants in hazelnut (Corylus avellana L.) are described. In contrast to normal trees in which physiological rest, or dormancy, is induced by short days, mutants fail to respond to this stimulus. Shoot tips continue to grow, old leaves are retained until midwinter when they are frozen and/or pushed off by developing axillary buds, axillary buds begin to grow in December, 2–3 months before normal spring bud break, and cold hardiness does not develop. Nondormancy is controlled by a single recessive gene (dd). The mutation is not uncommon since eight cultivars, including the world's most important commercial cultivars, are heterozygous for this trait. The implications of nondormancy in a temperate tree species are discussed in relation to evolution, extension of the range of cultivation, breeding, and value for basic studies of fundamental mechanisms of dormancy.     

欧洲榛子贮藏及萌发生理特性研究

对欧洲榛子(Corylus avellanaL.)在沙藏、萌发、幼苗生长阶段的种仁养分和保护酶活性动态变化特点进行了研究,结果表明:种子萌发后107 d营养耗尽;沙藏过程中种仁的干重、粗脂肪含量略下降,萌发后下降迅速且与时间呈线性负相关;可溶性糖在沙藏至萌发后12 d内下降而后上升,萌发24 d后上升迅速,72 d后进入高峰期;淀粉含量在沙藏过程中下降,萌发后上升并在萌发48 d取得11.12%的峰值后下降;游离氨基酸总量在沙藏期间下降,萌发前12 d开始升高,在萌发36~48 d达155.31 mg/100 g的高峰后降低;可溶性蛋白50.87 mg/g的峰值出现在萌发前12 d;SOD在萌发前12 d至萌发后12 d、CAT由萌发起24 d内、POD在萌发36 d后分别出现活性高峰,对种仁营养按测定时间进行的聚类分析结果与依据幼苗干重划分的幼苗生长阶段相吻合。     

Endogenous hormonal content and somatic embryogenic capacity of Corylus avellana L. cotyledons

Endogenous indole-3-acetic acid (IAA), abscisic acid (ABA) and cytokinins [zeatin (Z) zeatin riboside, dihydrozeatin, dihydrozeatin riboside, N⁶-isopentenyl adenine (iP) and N⁶-isopentenyladenine riboside] were evaluated in hazelnut (Corylus avellana L.) cotyledons of different developmental stage and genetic source for their somatic embryogenic capacity. There was an inverse correlation between the embryogenic potential of cotyledons and the degree of maturity of zygotic embryos, the first characteristic being associated with iP-type cytokinins and the second with Z-type cytokinins. Although the differences in total cytokinin, ABA and IAA contents between the cotyledons were small, the IAA/ABA and, mainly, the iP-type/Z-type cytokinin ratios were found to be two good indexes of the embryogenic competence of explants, suggesting that the endogenous hormonal balance is a very important factor defining the in vitro potential of hazelnut cotyledons. Received: 6 January 1997 / Revision received: 3 March 1997 / Accepted 1 April 1997     

On the size of Corylus avellana L. pollen mounted in silicone oil

A considerable variation in the size of modern Corylus avellana pollen mounted in silicone oil was noticed. It turned out that a residue of the silicone oil solvent (benzene) prevents shrinkage of the pollen grains, and that size-variations may be due to more or less incomplete evaporation of the solvent. Evaporation at 50[ddot]C is more effective than evaporation at room temperature. Diffusion of solvents from a plastic spatula and from the slide-sealing material may cause a swelling of the pollen. The size of pollen grains compressed by the cover slip may increase slightly due to deformation. Size changes with storage up to 17 years are random, compressed grains do not swell, and the average changes are insignificant. The size of Corylus pollen from various modern collections is compared.     

Diterpenoid production in hairy root culture of Salvia sclarea L

Growth and diterpenoid accumulation (salvipisone, ferruginol, aethiopinone and 1-oxoaethiopinone) during the growth cycle of a Salvia sclarea hairy root culture are described. The roots transformed by Agrobacterium rhizogenes (LBA 9402) were cultured in half-strength B5 liquid medium supplemented with 30 g L(-1) sucrose under light (16 h/8 h light/dark). A culture period of 30 days was optimal for both biomass and diterpenoid production. The total content of four diterpenoids in the hairy roots [(27.3 +/- 0.6) mg g(-1) dry weight] was higher than that of roots of field-grown S. sclarea plants [(3.15 +/- 0.15) mg g(-1) dry weight]. In transformed roots, aethiopinone was the main diterpenoid, whereas the principal diterpenoid of natural roots was salvipisone.     

Adventitious root induction inCorylus avellana L. cotyledon slices

Summary An experimental rooting system was developed to study in vitro adventitious root formation in hazelnut cotyledons. Experiments involveda) assay of several culture media,b) use of different developmental status of the seeds (germinated and ungerminated),c) cotyledons subjected to various light regimes, andd) different size of cotyledons slices. It was observed that higher rooting was induced in cotyledonary portions of 5- or 7-mm thickness (250 and 350 mm³, respectively) cultured on half-strength basal medium supplemented with 50 μM indole-3-butyric acid and 5 μM kinetin. Rooting was affected by light and the developmental state of seeds. Preinitiation, initiation, and root manifestation stages were defined according to specific culture periods and in relation with morphologic and histologic changes. The first histologic changes (cell division and root primordia induction) were observed after 12 days in culture. At 30 days of culture in rhizogenic medium root primodia were fully differentiated with well-developed vascular tissues.     

Agrobacterium infection of hemp (Cannabis sativa L.): establishment of hairy root cultures

Abstract

Experimental conditions were optimized for hemp, a difficult to transform plant, to be effectively infected with either Ri or Ti plasmid-bearing agrobacteria and to establish stably transformed tissues. Hypocotyl of intact seedlings was the most responsive material and the response depended on both bacterial strain and plant variety. Transformed tissues, hairy roots and tumors, were cultured and stabilized in vitro and showed the characteristic traits of fast and phytohormone-independent growth as well as high incidence of lateral branching and abundance of root hairs in the case of roots. They all contained T-DNA of the corresponding Ri or Ti plasmid as revealed by PCR analysis with specific primers and further hairy roots induced by AR10GUS strain showed normal pattern of β-glucuronidase positive staining. To our knowledge, this represents the first reported protocol for the establishment of Cannabis sativa hairy root cultures.     

In vitro establishment of a cycloclonal chain from nodal segments and apical buds of adult hazel (Corylus avellana L.)

Apical buds (0.5 cm) and nodal shoot segments (1.5 cm) excised from: A) field-grown branches, B) newly developed shoots from the forced outgrowth of axillary buds on A branches, C) newly developed shoots from the forced outgrowth of axillary buds on A branches submitted to cold storage were used as primary explants. Results indicate that three months cold storage greatly increases morphogenic capacity and reduces contamination and oxidation of tissues. Consequently, a multiplying chain could be easily established by culturing the tissues on a modified Murashige & Skoog (1962) medium plus 6-benzyl-aminopurine 5 mg l^-1, indole-3-acetic acid 0.01 mg l^-1 and gibberellic acid 0.1 mg l^-1. During the initiation and proliferation phases, both the proliferation and the elongation rate were significantly increased when a double-phase culture system (Viseur 1987) was used, giving rise to a higher microplant production than the one obtained using previously described methods. Plant regeneration was achieved by immersing the single microshoot's basal end in an IBA (0.1–1 mg ml^-1) solution for 10 s followed by a 20-day culture on a 1/2 MS2 medium.Abbreviations BAP 6-benzylaminopurine - GA₃ gibberellic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2ip 2-isopentenyladenine - MS1 and MS2 modified Murashige & Skoog media - NAA 2-maphtaleneacetic acid     

In vitro plantlet regeneration through asexual embryogenesis in cotyledonary segments of Corylus avellana L.

Cotyledonary nodes of corylus avellana L. excised from young seedlings cultured in K(h) medium for 5 weeks were used to induce embryoid formation. Embryogenesis was achieved in 60% of the explants over two 20-day culture steps in the presence of IBA (5 μM) plus BAP (0.5 μM) and BAP (5 μM) plus IBA (0.5 μM) respectively. Subsequent proliferation was successfully maintained during 5 subcultures on K(h) basal medium and in an unlimited number of subcultures in the presence of BAP (0.5 μM). Plant regeneration (50–55%) was easily achieved by planting into a basal K(h) medium after 10–20 days.     

Orderly arrangement of ribosomes in the embryogenic callus tissue of Corylus avellana L

Cultured callus tissue of hazel (Corylus avellana L.), which has the potency of somatic embryogenesis, was used for the study of cell ultrastructure in the course of callus growth and embryoid formation. The meristematic cells of this tissue exhibit a specific organization of rough endoplasmic reticulum (RER), stacked into extensive parallel sheets. The membranes of the aggregated RER are associated with orderly arrays of bound ribosomes. The high regularity of the alignment of the attached ribosomes seems to be influenced by the distance between the two neighbouring membranes in the RER aggregate. The RER aggregates with orderly attached ribosomes are more frequently found in callus cells and in early embryogenesis than in the advanced stages of embryo development.     

Quercetin 3-glucosylgalactoside from pollen of Corylus avellana

The main flavonoid glycoside from the pollen of Corylus avellana has been characterized as quercetin 3-O-(2″-O-β-d-glucopyranosyl)-β-d-galactopyranoside on the basis of UV, ¹H NMR, ¹³C NMR and mass spectral data and GLC sugar analysis.     

Use of Chenopodium murale L. transgenic hairy root in vitro culture system as a new tool for allelopathic assays

We investigated Chenopodium murale transgenic hairy root in vitro culture system as a new tool for allelopathic assays. Transgenic hairy roots were induced by Agrobacterium rhizogenes A4M70GUS from roots, cotyledons, leaves, and internodes of C. murale seedlings. Roots were found to be the best target explants, providing transformation efficiency of up to 11.1%. Established hairy root clones differed in their morphology and growth potential. Molecular characterization of these clones was carried out by PCR, RT-PCR and histochemical GUS analyses. No differences in rol gene expression were observed. Liquid culture system of characterized hairy root clones was maintained for over 2 years. Six hairy root clones were selected for assaying the allelopathic effect of their growth medium against germination and seedling elongation of wheat and lettuce test plants. The inhibitory potential varied depending on the hairy root clone. Some transgenic clones showed significantly higher inhibition compared to wild-type roots. These results revealed that hairy roots as an independent system synthesize some bioactive substances with allelopathic activity and exude them into the growth medium. Concentrations of caffeic, ferulic and p-coumaric acids (0.07-2.85 μmol/L) identified by HPLC analysis in the growth media were at least 1000 times lower than the inhibitory active concentration (5 mmol/L) of pure grade phenolic acids, suggesting that they have a limited role in the allelopathic phenomena of C. murale. The presented hairy root system appears to be a suitable tool for further investigation of the potential and nature of root-mediated allelopathic interference of C. murale.