Delayed flowering and reduced branching in micropropagated mature wild cherry (Prunus avium L.) compared with rooted cuttings and seedlings

The development of micropropagated wild cherry (Prunus avium L.) was compared in the nursery and the field with cuttings and seedlings, over a total period of 6 years. Summer semi-hardwood cuttings tended to produce moderate numbers of branches in the season following propagation, whereas micropropagules and seedlings produced significantly fewer or none at all. Removal of branches from cuttings resulted in taller trees. A greater proportion of cuttings than micropropagules flowered in the first year in which trees produced flowers. In the second flowering year, there were no differences in flowering habit between cuttings and micropropagules. Propagation by cuttings or micropropagation did not consistently affect increments in stem diameters or heights. These results are discussed in terms of the suitability of micropropagation and cuttings to produce clonal wild cherry. Received: 23 February 1997 / Revision received: 3 January 1998 / Accepted: 5 February 1998     

Style antigens of Prunus avium L.

Antiserum to a protein fraction of an extract of mature styles of P. avium cv. Lambert (S ₃ S ₄) was raised in rabbits. Two major antigenic components of the style extracts were detected by immunoelectrophoresis and immunodiffusion. The presence of one antigen (S-antigen) correlated with a particular S-genotype (S ₃ S ₄). This antigen is restricted to mature styles of P. avium. The second antigen (P-antigen) was detected in styles of all Prunus species examined, but not in styles of other species of the Rosaceae. The S-antigen is positively charged and the P-antigen negatively charged at pH 8.8.     

Mechanical stimuli regulate the allocation of biomass in trees: demonstration with young Prunus avium trees

Background and Aims

Plastic tree-shelters are increasingly used to protect tree seedlings against browsing animals and herbicide drifts. The biomass allocation in young seedlings of deciduous trees is highly disturbed by common plastic tree-shelters, resulting in poor root systems and reduced diameter growth of the trunk. The shelters have been improved by creating chimney-effect ventilation with holes drilled at the bottom, resulting in stimulated trunk diameter growth, but the root deficit has remained unchanged. An experiment was set up to elucidate the mechanisms behind the poor root growth of sheltered Prunus avium trees.

Methods

Tree seedlings were grown either in natural windy conditions or in tree-shelters. Mechanical wind stimuli were suppressed in ten unsheltered trees by staking. Mechanical stimuli (bending) of the stem were applied in ten sheltered trees using an original mechanical device.

Key Results

Sheltered trees suffered from poor root growth, but sheltered bent trees largely recovered, showing that mechano-sensing is an important mechanism governing C allocation and the shoot–root balance. The use of a few artificial mechanical stimuli increased the biomass allocation towards the roots, as did natural wind sway. It was demonstrated that there was an acclimation of plants to the imposed strain.

Conclusions

This study suggests that if mechanical stimuli are used to control plant growth, they should be applied at low frequency in order to be most effective. The impact on the functional equilibrium hypothesis that is used in many tree growth models is discussed. The consequence of the lack of mechanical stimuli should be incorporated in tree growth models when applied to environments protected from the wind (e.g. greenhouses, dense forests).Key words: Prunus avium, growth, mechanical stress, bending, biomass, shoot/root ratio, wind, shelter     

GA_1和GA_3在樱桃幼果及枝条中的代谢

ＧＡ_１和ＧＡ_３在樱桃幼果及枝条中的代谢马焕普（中国农业科学院果树研究所,兴城１２５１００）ＢｌａｋｅＰＳＢｒｏｗｎｉｎｇＧ（国际园艺研究中心,东茂林,英国）关键词：樱桃,赤霉素,代谢最近,Ｂｌａｋｅ等（１９９３）从樱桃（Ｗ。ｕｓａｕｎ）幼果中分离出...     

Tissue Development in the Stigma of Prunus avium L.

The tissue inside the stigma of Prunus avium L, through whichpollen tubes grow, undergoes a specific pattern of developmentwhich is different from that of the papillae on the stigmaticsurface or the transmitting tissue of the style in several importantaspects An elaborate system of intercellular spaces developsconsisting of small lacunae and aerenchymatous tissue The majorityof spaces contain no intercellular substances and appear tobe air canals, although the small lacunae may participate insecretion Aerenchymatous tissue on the peripheral regions ofthe stigma is characterized by several cytological featureswhich change during ontogeny, such as nuclear inclusions, amyloplastinclusions, dumbbell-shaped mitochondria, cytoplasmic sequestrationand isolated segments of endoplasmic reticulum Occasional clustersof amyloplasts were also observed Prunus avium L, sweet cherry, stigma, cytology, ultrastructure     

甜樱桃品种及其砧木的RAPD分析

利用RAPD技术,从130个随机引物中筛选出46个引物,对欧洲甜樱桃、欧洲酸樱桃、马哈利樱桃和野生中国樱桃4个类型樱桃种,以及欧洲甜樱桃与中国樱桃的种间杂交种共15个品种的基因组遗传变异进行分析。结果表明,46个随机引物均得到了稳定可重复的RAPD图谱,扩增出的DNA条带大小在100~2625bp之间,多态性位点数517个,多态性位点百分率为98.85%,每个随机引物扩增出的多态性DNA条带数在4~23条。品种间Nei遗传距离在0.166~0.479之间,平均遗传距离0.329;甜樱桃新品种‘秦樱1号’与‘秦岭玛瑙’、‘CDR-1’等10个樱桃砧木之间的遗传距离在0.248~0.376,并且根据遗传距离可以相互区分,所分析的15个樱桃品种均扩增出了特有的DNA条带,每个樱桃特有标记带在2~17个之间,共扩增出149个特有标记,据此可以进行樱桃品种及砧木的RAPD鉴定。研究认为利用RAPD技术可以在分子水平上对甜樱桃品种及其砧木进行快速鉴定。     

Inheritance and linkage of isozymes in sweet cherry (Prunus avium L.)

Eight polymorphic isozyme loci, 6PGD, G6PD, MDH, PGM, SKDH, FDP, GOT and IDH, in sweet cherry where found to be in one linkage group, with a ninth isozyme locus, GPI, being in another linkage group on a different chromosome. Isozymes were also linked to the incompatibility S locus and this explained the disturbed segregation ratios observed in the first generation from controlled hybridisations between different sweet cherry cultivars. Analysis revealed close linkage between the isozyme and S loci. The results supported a pre-existing theory that the S gene in cherry consists of three linked segments each coding for a different function. Progeny derived from selfing of Stella, the self-fertile cherry cultivar, also showed disturbed segregation ratios and an absence of homozygotes for the isozyme loci assayed. This demonstrated that codominant inheritance of the S alleles had not been effected by the self-fertile mutation.     

Metabolic profiling of ethephon-treated sweet cherry (Prunus avium L.)

Increasing costs and decreasing labor availability for sweet cherry harvest in Washington State, USA, has reinvigorated commercial and research interest of mechanized harvest. Ethephon (2-chloroethyl phosphonic acid) can be used to improve fruit abscission for mechanical harvest. Our previous work shows that 3.5 l ha⁻¹ ethephon enhances red color and reduces firmness of the cultivar ‘Bing’. In the current study, we used metabolic profiling of cultivars ‘Bing’, Chelan’, and ‘Skeena’ fruit meso and exocarp tissue to better understand underlying quality-related metabolism associated with ethephon application. Trees were treated using air-blast sprayer 13–14 days prior to harvest and fruit samples were harvested every 7–10 days starting at least 17 days prior to commercial harvest. Nearly 200 identified and partially characterized metabolites from mesocarp and exocarp tissue were characterized and evaluated. Principal component analysis models revealed changes in the metabolome associated with both natural ripening and ethephon-induced changes, including associations to key color, acid, and sugar components, such as cyanidin 3-glucoside, malic acid and sugar metabolism.     

Gibberellins in relation to flowering in Polianthes tuberosa

Endogenous gibberellins (GAs) in corms of Polianthes tuberosa L. (cv. Double) were isolated and identified by high performance liquid chromatography, bioassay and combined capillary gas chromatography-mass spectrometry (GC-MS). Gibberellins A₁, A₁₉, A₂₀ and A₅₃ were quantified at the vegetative, early floral initiation and flower development stages. The identification of 13-hydroxylated GAs indicates the presence of the early 13-hydroxylation pathway in P. tuberosa corms. An increase in GA₁ and GA₂₀, and a decrease in GA₁₉ levels, coincided with the transition from the vegetative phase to the stages of early floral initiation and flower development. GA₅₃ stayed at constant levels at the 3 different growth stages. The absence of GA₁ in vegetative corms and its presence in corms at early floral initiation and flower development stages suggest that GA₁ is a causal factor in inducing floral initiation in P. tuberosa . When GA₁, GA₃, GA₄, GA₂₀ and GA₃₂ were applied to corms at the vegetative stage (plants about 5 cm in height), floral initiation was promoted by all of the GAs used, GA₃₂ being the most active. In contrast with the other GAs, GA₃₂ had no effect on stem elongation. Therefore, it is suggested that hydroxylated C-19 GAs play an important role in flower induction in P. tuberosa .     

Characterisation of novel S-alleles from cherry (Prunus avium L.)

In plant populations exhibiting gametophytic self-incompatibility, individuals harbouring rare S alleles are likely to have a reproductive advantage over individuals having more common alleles. Consequently, determination of the self-incompatibility haplotype of individuals is essential for genetic studies and the development of informed management strategies. This study characterises six new S alleles identified in wild cherry (Prunus avium L.). Investigations to determine the S genotype of individuals in recently planted woodland through length polymorphisms of introns associated with the stylar S-RNase gene and the pollen SFB gene revealed six S intron profiles which did not correspond to those of known S alleles. These are now attributed to S ₂₇ to S ₃₂ . Consensus primers, annealing in the S-RNase sequence coding for the signal peptide and C5 regions, were used to isolate the S-RNase alleles associated with the novel S intron profiles. The proteins corresponding to the new alleles were separated by isoelectric focusing from stylar extracts and their pI values determined. Similarities between the deduced amino acid sequence for the new alleles isolated and other cherry S-RNase sequences available on the databases ranged from 40% to 86%. Amplification products for SFB introns ranged from 172 to 208bp. New sequence regions exposed to positive selection were identified and the significance of the PS3 region reinforced. A phylogenetic relationship between P. avium S-RNases for S ₁₀ and S ₁₃ and between corresponding SFB alleles may indicate co-evolution of allele specificities of these two genes. The nucleotide sequences reported in this paper have been submitted to the EMBL/GenBank database under the following accession numbers: S ₂₇ (DQ266439), S ₂₈ (DQ266440), S ₂₉ (DQ266441), S ₃₀ (DQ266442), S ₃₁ (DQ266443), S ₃₂ (DQ266444).     

Phosphoenolpyruvate carboxykinase in cherry (Prunus avium L.) fruit during development

In this study the abundance and location of phosphoenolpyruvate carboxykinase (PEPCK) was determined in the flesh and skin of the sweet cherry (Prunus avium L.) cultivar Durone Nero II during development. PEPCK was not present in young fruit but appeared in both tissues as the fruit increased in size. In these there was no net dissimilation of malic acid, which accounts for the bulk of their organic acid contents when PEPCK was present. To assist in understanding the function of PEPCK, the abundance of a number of other enzymes was determined. These enzymes were aspartate aminotransferase (AspAT), glutamine synthetase (GS), phosphoenolpyruvate carboxylase (PEPC), pyruvate, orthophosphate dikinase (PPDK), and ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). A potential role for PEPCK in the regulation of pH and the utilization of malate in gluconeogenesis in the flesh and skin of cherries is presented.     

Chloroplast DNA study in wild populations and some cultivars of Prunus avium L.

The PCR-RFLP technique was used to detect chloroplast DNA diversity in wild populations of Prunus avium from five European deciduous forests and some cultivars. A study of 10.8% of the total chloroplast genome detected eight insertion-deletion (indel) mutations, distributed over 12 haplotypes. Six haplotypes (H1, H2, H3, H4, H5 and H6) were found in wild populations and eight (H2, H6, H7, H8, H9, H10, H11 and H12) in the cultivars. Only two haplotypes (H2 and H6) are shared by the wild populations and the cultivars. The most-abundant and frequent haplotype in wild populations is H2 (frequency=78%). The wider geographical distribution along with the high frequency reflects its ancient origin. Of the five populations, three are polymorphic. Populations GA (Scotland) and KE (Germany) have unique haplotypes. The total cpDNA diversity in wild populations is h_T=0.40, and a major portion of it is within populations (h_S=0.37). The genetic differentiation among populations was low (G_STC=0.08) and no genetic structure among wild populations was observed. A minimum-length spanning tree, demonstrating relationships among the haplotypes in wild populations, indicated two possible chloroplast lineages. The ten identified cultivars were represented by seven haplotypes; this result proposes the possible utilisation of the PCR-RFLP technique for the characterisation of sweet cherry cultivars. The cpDNA diversity in P. avium should be considered carefully for phylogenetic studies involving this species. Received: 10 July 2000 / Accepted: 19 October 2000     

Gibberellins in apical shoot meristems of flowering and vegetative sugarcane

Gibberellins A₁, A₃, iso-A₃, A₄, A₁₉, A₂₀, and A₃₆ were identified by gas chromatography-selected ion monitoring in apices of sugarcane (Saccharum spp. hybrids). Flowering apices (i.e., 2–4 cm panicle) contained 8–9 times more (estimated by bioassay) endogenous gibberellins A and iso-GA₃ (ratio of 1:6:8, respectively; in total 51 ng g^–1 fresh weight) than vegetative apices (6.4 ng g^–1 fresh weight). Vegetative apices contained small but significant levels of GA₁₉, which could not be detected in flowering apices; vegetative apices also contained approximately four times more of a GA₃₆-like substance than flowering apices. Since the two apex types developed under the same photoperiod, the increased levels of GA and iso-GA₃ and the reduced levels of GA₁₉ and GA₃₆-like substances are correlated with the flowering state rather than with photoperiod or photoperiod changes per se. Since there were relatively high levels of C₁₉ GAs along with low levels of C₂₀ GAs in flowering apices, and since the converse is true in vegetative apices, metabolism of C₂₀ to C₁₉ GAs may be enhanced in flowering apices.Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by U.S. Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.     

Stigmatic and stylar incompatibility in Prunus avium L.: Morphological and ultrastructural aspects

Abstract

Stigmatic and stylar structures of-sweet cherry (Prunus avium L.) «Malizia» were examined with light and electron microscopes (S.E.M. and T.E.M.).

It was demonstrated that the transmitting tissue, situated in the central portion of the style, extends below the stigmatic papillae and secretes an electrondense material accumulating in the intercellular spaces. Pollen tubes which germinated on the stigma, reached the ovules passing through this substance which facilitates their passage while trophic relations are established.

Some ultrastructural aspects of the pollen tubes observed inside the style were examined and discussed in relation to the phenomenon of self-incompatibility.     

Gibberellins and early growth in seedlings of Phaseolus vulgaris

Summary 1. Amounts of gibberellin extractable from young bean seedlings using phosphate buffer, and following acid hydrolysis, or protease treatment, have been examined and compared with those obtained using methanol extraction. 2. Considerable differences in the amounts of gibberellins extractable are found for different batches of material. The level of extracted gibberellin is less for dry seeds and for 1-day old seedlings than for seedlings 4 days old. Before germination, the amounts of free, buffer-soluble, gibberellins are low, but these rise rapidly in the postgermination period. 3. The appearance of large amounts of free gibberellins in the cotyledons, believed to represent the conversion of bound forms, is not dependent upon the presence of the embryonic axis, since removal of this at planting has only a small effect on the amount of gibberellin extractable at day 4. There is evidence for synthesis of new gibberellin in the intact seedling by day 4. 4. amylase activity in the cotyledons also develops in the absence of the embryo, but the high levels of activity shown by intact seedlings are not reached in cotyledons cultured in absence of the embryo.     

Tissue-specific antigens secreted by suspension-cultured callus cells of Prunus avium L.

A number of antigenic components are secreted into the medium by P. avium callus cells derived from different tissues and grown in suspension culture. These antigens have been detected using antiserum raised in rabbits to a protein fraction secreted by P. avium leaf callus. One antigen is specific to leaf tissue and is secreted by callus cells derived from stem, pistil and anthers as well as leaves. A second antigen is, in intact organs, restricted to styles of a particular self-incompatibility (S) genotype, but is also secreted by callus cells derived from the leaf. Another antigen, apparently not organ-specific, is secreted by all calli tested, including Rosa (cv. Paul's Scarlet).     

Distribution and fine-scale spatial-genetic structure in British wild cherry (Prunus avium L.)

Insights into the within-population spatial-genetic structure (SGS) of forest tree species, where little is known regarding seed and pollen dispersal patterns, enhance understanding of their ecology and provide information of value in conservation and breeding. This study utilised 13 polymorphic simple sequence repeat loci to investigate the impact of asexual recruitment, management regime and tree size on the development of SGS in wild cherry (Prunus avium L). Only 246 genotypes were identified in the 551 trees sampled, reflecting significant levels of clonal reproduction in both managed and unmanaged populations. Naturally regenerated wild cherry was spatially aggregated under both management regimes. However, in the managed population, sexually derived trees accounted for a greater proportion of the smaller size classes, whereas vegetatively produced trees dominated the smaller size classes in the unmanaged population. High overall SGS values (Sp 0.030-Sp 0.045) were observed when considering only sexually derived genets and kinship coefficients were significant up to the 120 m distance class for both populations. The inclusion of clonal ramets in the analysis significantly increased the overall SGS (Sp 0.089-Sp 0.119) as well as kinship coefficients in the 40-80 m distance classes, illustrating the dramatic impact of vegetative propagation on SGS in this species. Increased spatial aggregation and regeneration appeared to be concomitant with increased SGS in the 40 m distance class in the unmanaged population. Neighbourhood size estimates were relatively small for both populations and kinship coefficients were found to decline with distance under both management regimes, suggesting that common mechanisms may restrict gene dispersal in wild cherry.     

The effects of external magnesium concentration on the growth and magnesium inflow rates of micropropagated cherry rootstocks 'F.12/1' (Prunus avium L.) and 'Colt' (Prunus avium L. × Prunus pseudocerasus L.)

The cherry rootstock 'F.12/1' is more susceptible to Mg deficiency than the cherry rootstock 'Colt'. The effects of different external concentrations (3000, 500, 50 and 10 µM) of Mg on the growth of micropropagated plants of 'F.12/1' and 'Colt' were investigated in a flowing solution culture system. The relative growth rates (RGR) and total dry weight of both cultivars decreased similarly with the reduction in the external concentrations of Mg. The decreases were caused by a lower net assimilation rate (unit leaf rate). 'F.12/1' had a greater RGR than 'Colt' at all external concentrations of Mg and this is ascribed to its greater leaf weight ratio (leafiness). 'Colt' partitions more dry matter to roots than 'F.12/1', resulting in a smaller shoot: root dry weight ratio. 'F.12/1' required a greater inflow rate of Mg than 'Colt' to maintain its maximum growth rate. When the external concentration of Mg fell below 500 µM the concentration of Mg in the leaves of 'F.12/1' fell well below the critical concentration whereas for 'Colt' this did not occur until the concentration fell below 50 µM.