Floral analysis cannot be considered as an alternative to the foliar diagnosis in the olive

Correlations between macro and micronutrient concentration of olive leaves and those obtained in floral buds at five development stages, were studied in order to evaluate the utility of floral analysis for the diagnosis of the nutritional status of olive orchards. Olive leaves from ‘Arbequina’, ‘Frantoio’, ‘Hojiblanca’, ‘Bella de España’ and ‘Picual’ cultivars were taken during July of 2002 and 2003. Samples of floral buds were collected at five development stages: closed bud (E), petal fall (G), G + 15 days, G + 30 days and pit hardening (H). Results showed a lack of signification of the correlation coefficients between leaf and floral analysis for N, P, K, Ca, Mg, B, Zn, Mn, Fe, Cu and Na in both years of the experiment. The few significant correlations obtained were not repeated in both years. Therefore, the results indicate that floral bud mineral analyses cannot substitute the foliar diagnosis to establish the nutritional status of the olive orchards.     

Rose (Rosa hybrida L.) EST-derived microsatellite markers and their transferability to strawberry (Fragaria spp.)

The ‘Genome database for Rosaceae (GDR)’ provides a large collection of expressed sequence tags (ESTs) harboring simple sequence repeats (SSRs) from several Rosaceae genera, including Rosa (rose). Primer pairs flanking SSR were designed for 312 unique Rosa ESTs based on GDR database. Eight rose (Rosa hybrida L.) genotypes were tested for PCR amplification, and 287 (92%) of the primer pairs generated allele-specific PCR bands that were readily scored. From 183 (63.7%) primer pairs that evidenced polymorphic alleles among the eight rose cultivars, 20 pairs evidencing EST sequence homology to known gene functions and high levels of polymorphism were selected and utilized for DNA fingerprinting and genetic diversity assessments of 47 rose hybrids. A total of 202 polymorphic bands were scored and generated unique fingerprints for each rose hybrid. The Nei–Li genetic similarity coefficients among 1081 pair-wise comparisons of 47 cultivars exhibited a broad range of genetic variations from 0.30 (‘Grand King’ and ‘Carnival’) to 0.99 (‘First Red’ and ‘Red Champ’). UPGMA cluster analysis divided 47 hybrids into five major groups and two sub-groups. The cross-species transferability of 273 EST-SSR primer pairs was evaluated using four genotypes of the strawberry, a genus member of the Rosaceae family. PCRs on the DNA samples of strawberry were successful for 165 primer pairs; among these, 123 pairs amplified 243 polymorphic bands. As surrogates of the marker transfer, the phenetic relationship among the four strawberry genotypes was evaluated. Genetic similarity coefficients varied from 0.78 (‘Maehyang’ and ‘Janghyee’) to 0.64 (‘Janghyee’ and ‘Pragana’). The results of cluster analysis showed that the three octaploid strawberry cultivars were quite similar, whereas the diploid ‘Pragana’ was related distantly at the genomic DNA level. The EST-SSR markers developed in the present study can be efficiently utilized for genetic diversity studies in Rosaceae.     

DNA fingerprinting of olive varieties in Istria (Croatia) by microsatellite markers

The Istria region, where olives have been cultivated for many centuries, is characterized by a considerable variety of microclimates. The study of varieties traditionally cultivated in Croatian Istria and their relationships with varieties in historically and geographically connected regions is very important in order to identify native olive germplasm, well adapted to local conditions, and to characterize the oil of regional origin. Twelve olive microsatellite markers were used for identification and differentiation of a set of 27 olive accessions grown in Istria (Croatia). Among the 27 accessions, 18 different SSR profiles were discriminated. All 12 microsatellite markers analysed were polymorphic, revealing a total of 81 alleles. The number of alleles per locus ranged from four to nine. This is the first molecular characterization of olive germplasm in Croatian Istria. The analysis clarified the genetic relationships of varieties native to Croatian Istria with introduced olive varieties, as well as with varieties in the neighbouring Slovene Istria region. Numerous varieties in neighbouring regions showed high similarity and a few cases of synonymy (‘Bilica’-‘Bjankera’; ‘Buga’-‘?rna’) and one Croatian-Slovenian homonymy (‘Bu?a’-‘Buga’) were observed. The results provide useful information for a native germplasm survey and can be used for the construction of a unique database comprising all olive varieties in the Istrian region of Croatia and Slovenia.     

Identification of S-alleles in pear (Pyrus communis L.) cv. ‘Rocha’ and other European cultivars

In this work we report the cloning and identification of S-RNase alleles responsible for gametophytic self-incompatibility (GSI) of ‘Rocha’ pear and of 13 other European pear cultivars that might be used as its pollinators. Partial sequences of S-RNase alleles were amplified by PCR with specific primers hybridising in conserved regions of previously identified S-RNase alleles of Pyrus communis, cloned and sequenced and the S-genotype of eight pear cultivars was fully determined. Three cultivars (‘General Léclerc’ (SqSl), ‘Tosca’ (SbSl) and ‘Alexandrine Douillard’ (SbSk)) shared no S-alleles with ‘Rocha’ (SaSe) and shall be totally compatible with this cultivar. None of the cultivars analysed showed an identical amplification pattern to the one observed in ‘Rocha’, so the other cultivars shall be at least semi-compatible. One new allele was identified in P. communis cv. ‘Beurré d’Avril’ (designated as St). The determination of both S-RNase alleles of cvs ‘Rocha’, ‘Beurré Precoce Morettini’ (SeSk) and ‘Tosca’ and the identification of one S-RNase allele in cvs ‘Carapinheira’ (Sb), ‘Amêndoa’ (Se), ‘Pérola’ (Sk) and ‘Beurré d’Avril’ (St) are important contributions for the effort recently developed worldwide to establish groups of sexual compatibility among European pears.     

Growth,biomass allocation and leaf ion concentration of seven olive (Olea europaea L.) cultivars under increased salinity

Olive (Olea europaea L.) is the major fruit tree in the Mediterranean region, often grown in locations where plants are exposed to increased salinity. To determine the effect of NaCl on shoot and root growth, dry matter allocation, leaf Na⁺ and K⁺ concentration, electrolyte (EL) and K⁺ leakage (KL), seven olive cultivars of different origins were grown in nutrient solution containing 0, 33, 66, 100 or 166 mM NaCl for three months. The general effect of salinity was linear and quadratic decrease of observed plant growth parameters. Different responses of tested cultivars to applied levels of salinity were found for stem dry weight, shoot length and number of leaves. As salinity increased, growth of ‘Manzanillo’ declined sharply, whereas ‘Frantoio’ was the most tolerant to growth reduction in most of the observed growth parameters. Allometric analysis showed that biomass allocation under salinity stress was similar in all cultivars, but the slope between shoot weight and total plant weight decreased as salinity increased. Since the higher allocation in roots was not found, it seems that salinity only slowed the above ground plant canopy growth. Sodium concentration in leaves of all cultivars increased as salinity increased with the highest increment reached when the salinity of nutrient solution was raised from 100 to 166 mM NaCl. Significant differences among genotypes were found in leaf Na⁺ and K⁺ concentration and K⁺:Na⁺ ratio, but they were not related to the growth rate. Generally, ‘Frantoio’ and ‘Oblica’ accumulated less Na⁺ and were able to maintain higher K⁺:Na⁺ ratios as compared to other genotypes. Electrolyte leakage and KL linearly increased with increasing salinity and the magnitude of the response depended upon the olive cultivar.     

Influence of cultivar and site of cultivation on levels of lipophilic and hydrophilic antioxidants in virgin olive oils (Olea Europea L.) and correlations with oxidative stability

Oxidation stability is an important property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by cultivar, year and place of production. Polyphenols, tocopherols, carotenoids, chlorophylls and fatty acids levels were correlated to oxidative stability in olive oils from three experiments: cultivar influence (18 cultivars assessed for 4 years in the same place); environmental influence by mesoclimatic (4 cultivars from 17 sites in a single region for 4 years) and macroclimate conditions (3 cultivars from 3 different regions for 3 years). Total polyphenols and saturated on polyunsaturated fatty acids ratio were shown to be the major factors in oil antioxidant stability, according to multivariate regression models. Among the surveyed cultivars, oils from ‘Leccino’ and from three ‘local’, minor cultivars (‘Miniol’, ‘Regina’ and ‘Rossanello’) resulted in higher oxidative stability and oils from cultivars grown in Tuscany (central Italy) showed the highest oxidative stability by comparison with northern and southern regions.     

Analysis of genetic diversity among some Persian walnut genotypes (Juglans regia L.) using morphological traits and SSRs markers

There is a high diversity among cultivated walnut trees in Iran due to its long time of seed propagation and vast area of cultivation. In this study some morphological characters as well as Simple Sequence Repeat (SSRs) markers were used to analyze the genetic diversity and relationships among 31 Iranian walnut genotypes along with four foreign cultivars. The nut weight ranged from 7.52 to 17.73 g, kernel weight from 4.00 to 9.83 g, and kernel percentage ratio from 38.78 to 67.05% among studied genotypes. In SSRs analysis, nine primer pairs were tested that produced 39 alleles ranging from 2 to 8, with a mean value of 5.10 allele per primer. The Iranian genotypes showed relatively high diversity both for their SSRs loci and morphological traits. Although the foreign cultivars (‘Serr’, ‘Vina’, ‘Franquette’ and ‘Lara’) clustered with each other, they also laid close and within the Iranian genotype. The results of the study provided us with valuable diversity among our genotypes which could be used for breeding studies and also showed the power of genetic markers for analysis and evaluation of this diversity.     

In vitro propagation using adventitious buds technique as a source of new variability in chrysanthemum

Eleven cultivars of Chrysanthemum × grandiflorum (Ramat.) Kitam.: ‘Richmond’ and its 10 radiomutants, representing the Lady group, were propagated in vitro with shoot tips and leaves as explants. The aim of this study was to investigate if the explant type used for micropropagation affects the genotype and phenotype of chrysanthemums. Plants grown from shoot tips and adventitious buds formed on leaves were rooted in vitro, acclimatized and cultivated in glasshouse up to full-flowering. The colour and shape of inflorescences of plants obtained from two different explant types were compared within the cultivars. All plants derived from shoot-tip explants showed the inflorescence colour and shape typical for the cultivars. Inflorescence colour of plants derived from adventitious buds were true-to-type in four cultivars: ‘Richmond’, ‘Lady Amber’, ‘Lady White’ and ‘Lady Yellow’. All plants of ‘Lady Apricot’ (originally: golden beet) and ‘Lady Salmon’ (salmon) propagated from adventitious buds technique showed altered inflorescence colour (respectively: purple gold; pink and white). ‘Lady Bronze’ (originally: reddish brown), ‘Lady Orange’ (orange brown) and ‘Lady Rosy’ (purple gold) propagated with adventitious buds had both typical and changed inflorescence colours (respectively: yellow; yellow and red; reddish pink). ‘Lady Vitroflora’ showed altered number of ligulate florets grown into tubes in inflorescence when propagated with shoot tips and leaves as explants. Those changes might be an effect of either chimeral structure or somaclonal variation of the plants investigated. The variation appears only if non-meristematical explants were used. The adventitious buds technique might be useful in chrysanthemum breeding as a source of a new variability.     

Assessment of genetic diversity of Highland bananas from the National Banana Germplasm Collection at Rubona,Rwanda using RAPD markers

The genetic similarities of 49 accessions of bananas from The National Banana Collection at Rubona were investigated using random amplified polymorphic DNA markers. A total of 120 primers were screened for their usefulness in amplifying DNA fragments of four cultivars belonging to the subgroup Mutika–Lujugira. Fifteen random primers were selected for more detailed analysis, on the basis of providing reproducible amplification and revealing a high level of variation between the four cultivars. The genetic similarity was estimated using a simple matching coefficient which showed the lowest value of 0.46 between ‘Ingumba’ and ‘Ishika’ and the highest value of 0.85 between ‘Kirayenda’ and ‘Inyabukuwe’. The data of matrix of coefficient of similarity was subjected to cluster analysis using the unweighted pair group method with arithmetic average (UPGMA). Each accession was clearly separated. The results of this study are important for the curation of the banana germplasm collection in Eastern Central Africa and for future breeding of this crop.     

The fruit pitting disorder—A physiological anomaly in mango (Mangifera indica L.) due to deficiency of calcium and boron

A new disorder known as fruit pitting has been observed in some Indian mango orchards during the recent years. In this disorder, there is a development of some sunken pits on fruit peel, which distract consumers. Based on preliminary observations, it was observed that deficiency of nutrients could be the cause, and hence systematic studies were conducted in five indigenous cultivars such as ‘Alphonso’, ‘Amrapali’, ‘Dashehari’, ‘Mallika’ and ‘Neelum’, and five exotic mango cultivars such as ‘Edward’, ‘Irwin’, ‘Rosari’, ‘Sensation’ and ‘Tommy Atkins’ with the aim to observe the fruit pitting incidence and degree, and to investigate its probable causes. Our studies indicated that nearly 13% of the mango fruit was affected by fruit pitting with variable degree and magnitude. All indigenous cultivars had higher incidence of fruit pitting than exotic cultivars. ‘Dashehari’ had the maximum incidence of fruit pitting (30.3%), followed by ‘Amrapali’ (28.6%), and ‘Rosari’ the least (3.4%). Our studies indicated that the incidence of fruit pitting in mangoes was nearly 13% with a significant variability among the cultivars (Table 1). Although the concentrations of most of the major nutrients such as N, P, K, Mg, and minor nutrients such as Cu, Mn, Fe, Zn, did not differ significantly. However, the pitted fruit had lower Ca (1.53%) and B (22 mg kg⁻¹) concentrations than normal fruit (2.47% and 38 mg kg⁻¹, respectively), indicating that deficiency of Ca and B probably is the cause for fruit pitting in mangoes.     

Influence of time of harvest and maturity index on olive oil yield and quality

Harvesting plays a major role in the virgin olive oil production line, being the most expensive single component, but also due to its significant effect on the whole year's produce. Previous studies have focused on the effects of harvest timing on either oil yield or quality. Here we determined the separate and combined effects of harvesting date, fruit maturation, cultivar and fruit load on olive oil quality and quantity. Cultivars typical to the Middle East region were selected: the traditional cv. Souri and the newer cv. Barnea, grown under intensive conditions. The results demonstrate fundamental differences between the two cultivars with respect to harvest strategy. In high-yielding ‘Barnea’, oil accumulation continued throughout the ripening season resulting in increasing yield of oil with time while maintaining high quality. Hence, exploiting the production potential in ‘Barnea’ requires late harvest and advanced fruit maturity. However, in heavily loaded ‘Souri’, oil accumulation was accompanied by early massive shedding of fruits. Furthermore, late harvest and advanced maturation in ‘Souri’ were associated with a sharp increase in free fatty acids combined with a rapid decline in polyphenol content, and in MUFA to PUFA and saturated to unsaturated fatty acid ratios, all resulting in loss of oil quality. Rapid decline in oil yield coupled with deterioration of oil quality call for early harvesting at low maturity index in ‘Souri’. In medium-yielding trees of both cultivars, maturation progressed more rapidly, resulting in earlier harvest to utilize optimal oil potential.     

Comparison of anthocyanins in non-blotches and blotches of the petals of Xibei tree peony

A comparison in non-blotches and blotches of 35 cultivars of Xibei tree peony was investigated to explore flower coloration of Xibei tree peony (the second cultivar group in Chinese tree peony). With high performance liquid chromatography (HPLC) analysis, six anthocyanins including peonidin 3,5-di-O-glucoside (Pn3G5G), peonidin 3-O-glucoside (Pn3G), cyanidin 3,5-di-O-glucoside (Cy3G5G), cyanidin 3-O-glucoside (Cy3G), pelargonidin 3,5-di-O-glucoside (Pg3G5G), and pelargonidin 3-O-glucoside (Pg3G) were detected in non-blotches and blotches of petals. Total anthocyanins (TA), total flavones and flavonols (TF), and the copigmentation index (CI) were also analyzed. Cyanidin-based glycosides, which accumulated abundantly at the basal petal, resulted in blotch formation. Some peculiar cultivars with only one kind of anthocyanins or without anthocyanins in non-blotches were found in this study. For example, ‘Feng Zi Xiu Se’, ‘Ou Duan Si Lian’, and ‘Xi Wang’ contained only Pn3G5G; ‘Bing Shan Cang Yu’ and ‘Jin Bo Dang Yang’ contained only Cy3G; while no anthocyanins were found in ‘Bing Shan Xue Lian’. Several cultivars were rich in Pg-based glycosides, such as ‘Ni Hong Huan Cai’, and ‘Ju Yuan Shao Nv’. These cultivars would be excellent parents for creating new cultivars with novel flower color in the future.     

Investigation of the fertilization biology of some sweet cherry cultivars grown in the Central Northern Anatolian Region of Turkey

The experiments were carried out between 2003 and 2005 in the Province of Amasya. The first objective of the study was to determine the best pollinizer for the cultivar ‘0900 Ziraat’ which is the most popular sweet cherry cultivar (Prunus avium L.) in Turkey. The ‘0900 Ziraat’ was used as a female parent and ‘Türko?lu’, ‘Köro?lu’, ‘Kargayüre?i’, ‘Hac? Ali’, ‘Starks Gold’ and ‘Geçkiraz’ were used as pollinizer cultivars. In 2003, for the hand cross pollination combinations, fruit set was between 31.25% and 42.80%. In 2004, fruit set was reduced by spring frost and was between 9.69% and 15.24%. Additionally, the blooming periods of the experimental cultivars, fruit set of open pollination and hand self pollination were examined. The fruit set ratios of all tested cultivars under open pollination conditions varied between 26.73% and 53.49% in 2003 and 4.38% and 38.35% in 2004. ‘Geçkiraz’ had the highest fruit set owing to its late flowering date. For open pollination, fruit set values of ‘0900 Ziraat’ were lower than hand cross pollination with other cultivars in 2003 when the results of both treatments are compared. On the contrary, fruit set was higher than hand cross pollination in 2004. In the present study, pollen germination values varied greatly among year, cultivar and sucrose concentration. Viability percentages were generally high, not less than 66%. According to phenological observations, partial or complete overlapping of the flowering period of ‘0900 Ziraat’ and its possible pollinizer cultivars were observed in 2003 and 2005. But in 2004, the flowering period overlapped for only ‘0900 Ziraat’ and ‘Geçkiraz’ cultivars. When blooming times are taken into consideration, ‘Geçkiraz’ was found to be the best pollinizer cultivar.     

Temperature responses,flowering and fruit yield of the June-bearing strawberry cultivars Florence,Frida and Korona

The effect of night temperature on short day (SD) floral induction has been studied in three June-bearing strawberry cultivars of different geographic origin and compared with yield performance in the cool Nordic environment. At the optimum day temperature of 18 °C, the SD flowering response of the cultivars ‘Florence’ and ‘Korona’ increased significantly with increasing night temperature from 9 to 18 °C, while an optimum was reached at 15 °C in the cultivar ‘Frida’ that is selected under cool-environment conditions in Norway. Also, while saturated flowering response was obtained with 3 weeks of SD treatment at all temperatures in ‘Frida’, several plants of ‘Florence’ and ‘Korona’ failed to initiate flowers at 9 °C night temperature even with 5 weeks of SD. The effect of extended SD period was particularly pronounced in ‘Florence’. The slow SD floral induction response of ‘Florence’ was associated with a 2 week delay of anthesis in subsequent long day (LD) conditions at 21 °C. Yield performance of the same cultivars during 2 years under field conditions at Nes Hedmark and in North Norway also demonstrated that the yield potential of ‘Florence’ was not realized under the climatic conditions prevailing at these locations. In both years the yields varied significantly among the cultivars, ‘Frida’ having the highest yields followed by ‘Korona’, with ‘Florence’ far below. It is concluded that, in the Nordic environment, autumn (September) night temperatures are obviously sub-optimal for yield performance of some June-bearing strawberry cultivars, and that this effect is mediated by autumn temperature effects on flower initiation responses.     

The effect of forcing temperature on peony shoot and flower development

Pre-chilled potted plants of Paeonia ‘Coral Sunset’, ‘Monsieur Jules Elie’, ‘Sarah Bernhardt’, and ‘Karl Rosenfeld’ were placed in a range of controlled temperature regimes to ascertain the effect of temperature on the timing of shoot emergence and floral development. For all cultivars, warmer temperatures up to 25 °C lead to more rapid shoot emergence and flower development. Linear temperature responses adequately described the rate of development from shoot emergence to flower bud appearance, and from bud appearance to flower opening, but a curvilinear response was required to describe the time taken for shoots to emerge. There were significant differences between cultivars in the number of heat units required for shoot emergence, with the shoots of the slowest-developing cultivar, ‘Monsieur Jules Elie’, taking 50% longer to emerge than those of the most rapid, ‘Coral Sunset’. No significant differences were found among cultivars in the time taken from shoot emergence to flower opening, although the ‘split’ stage (when the bud opens sufficiently for petal colour to be observed) was slightly earlier in ‘Karl Rosenfeld’.     

Fruit characteristics of fig cultivars and genotypes grown in Turkey

In this study, fruit quality characteristics of some cultivars and types of fig (Ficus carica L.) were determined in Dortyol, Hatay, Turkey, which has a Mediterranean climate. The main fig cultivars grown in Turkey (‘Sarilop’, ‘Bursa Siyahi’, ‘Goklop’, ‘Yediveren’, ‘Yesilguz’, ‘Morguz’, ‘Sari Zeybek’, and ‘Ufak Yesil’) were evaluated along with 24 selections from a larger collection from the Mediterranean Region of Turkey. Several pomological characteristics of the genotypes were determined on 5-year-old trees during the 2001 and 2002 growing season. Averaged over the 2 years, fruit weight ranged between 22 and 52 g, total soluble solids content (TSS) ranged between 20.1 and 27.4%, and acidity ranged between 0.09 and 0.26%. ‘Bursa Siyahi’, ‘Goklop’, 31-IN-17, 31-IN-11 and 31-IN-09 produced the largest fruits in terms of fruit weight and dimensions. 31-IN-01, 31-IN-02, ‘Yesilguz’, ‘Morguz’ and ‘Ufak Yesil’ had the highest TSS. ‘Yediveren’, ‘Goklop’, ‘Bursa Siyahi’ and 31-IN-16 scored the highest in overall quality according to the weighted ranked method. Based on the results obtained ‘Yediveren’, ‘Goklop’ and 31-IN-16 could be alternatives to ‘Bursa Siyahi’, currently the most favored fresh table fig cultivar. These alternatives appear to have potential for both local consumption and export markets. Our results also indicate extensive diversity among Turkish figs permitting marketing of a broad range of fresh fig traits.     

Assessment of tolerance to NaCl salinity of five olive cultivars,based on growth characteristics and Na and Cl exclusion mechanisms

Changes caused by NaCl-induced salinity on several growth parameters and ions accumulation have been measured in five olive (Olea europaea L.) cultivars (‘Chemlali’, ‘Chetoui’, ‘Koroneiki’, ‘Arbequina I18’, and ‘Arbosana I43’) growing in a greenhouse in nutrient solution pot experiment. One-year-old plants were transplanted to sand–perlite (1:1) culture, and were irrigated with half-strength Hoagland nutrient solution containing NaCl at various levels (0.5, 50, 100 and 200 mM). Salinity induced significant decrease in growth parameters, but to a different extent in each cultivar. Leaf growth and total leaf area per plant were significantly affected by all salinity treatments in all studied cultivars, being ‘Arbequina I18’ the most sensitive cultivar. Leaf drop phenomenon was observed from 60 days after salt application at high salinity treatments, mainly in Arbequina I18. Contrary to leaf area, leaf thickness increased progressively during the experiment. ‘Chemlali’ developed thicker leaves at the two highest salinity treatments when compared to the other cultivars. Na⁺ and Cl⁻ concentrations were higher in roots than in shoots and leaves in most of the cultivars investigated. The effectiveness of Na⁺ exclusion mechanism in the roots differed significantly among studied cultivars, working effectively in ‘Chemlali’ (by inhibiting translocation of Na⁺ to the aerial part) and being much less efficient in ‘Arbequina I18’. Furthermore, leaf abscission can be considered as an additional tolerance mechanism of olive cultivars allowing the elimination of leaves that had accumulated Na⁺ and Cl⁻ ions. Tolerance to salinity stress was as follows: ‘Chemlali’ > ‘Chetoui’ > ‘Arbosana I43’ > ‘Koroneiki’ > ‘Arbequina I18’. This order of salt tolerance was indicated by lower reduction in plant growth parameters (shoot elongation, trunk diameter, total plant dry weight, internodes length, and total leaf area), the increase of leaf thickness, and by the effectiveness of the exclusion mechanism of Na⁺ and Cl⁻ in the root system.     

Pollen biology of ornamental ginger (Hedychium spp. J. Koenig)

An improved in vitro pollen germination assay was developed to assess the viability of stored Hedychium pollen. The effect of polyethylene glycol (PEG) (10, 15, and 20%, w/v) on pollen germination and tube growth was evaluated for Hedychium longicornutum and two commercial Hedychium cultivars, ‘Orange Brush’ and ‘Filigree’. Overall, the inclusion of PEG 4000 in the medium improved both pollen germination and tube growth for the three different genotypes tested and the results varied depending on genotype. In vitro germination was used to assess the viability of Hedychium pollen stored up to two months. Pollen nucleus status was determined for four Hedychium cultivars, ‘Orange Brush’, ‘Anne Bishop’, ‘Filigree’, and ‘Daniel Weeks’. Pollens of ‘Orange Brush’, ‘Anne Bishop’, and ‘Daniel Weeks’ were found to be binucleate but ‘Filigree’ was shown to possess both binucleate and trinucleate pollens. High pollen:ovule ratio values were obtained in several Hedychium taxa. The results obtained on the nuclear pollen status and pollen:ovule ratios will further our understanding of the pollination biology and help clarify the taxonomy and phylogeny of Hedychium species.     

EST-PCR markers developed for highbush blueberry are also useful for genetic fingerprinting and relationship studies in rabbiteye blueberry

The pedigrees of most rabbiteye blueberry (Vaccinium virgatum) cultivars can be traced back to four wild selections, ‘Ethel’, ‘Clara’, ‘Myers’, and ‘Black Giant’; thus, they result from a very narrow germplasm base and are highly related. Until now randomly amplified polymorphic DNA (RAPD) has been the only type of molecular marker used in rabbiteye blueberry. Here we have tested whether a type of sequence-tagged site (STS) marker which utilizes specific ∼20-mer primers from expressed sequence tags (ESTs) of highbush blueberry (V. corymbosum), called EST-PCR markers, are useful for genetic fingerprinting and relationship studies in rabbiteye blueberry. Of 44 EST-PCR primer pairs, from an assortment of genes expressed in flower buds of cold acclimated and non-acclimated plants, and shown to amplify polymorphic fragments among a collection of highbush genotypes, 40 (91%) resulted in successful amplification, and 33 of those (83%) amplified polymorphic fragments among the rabbiteye genotypes. The average number of scorable bands per primer pair was two. A dendrogram constructed from genetic similarity values, based on the EST-PCR marker data, tended to group siblings and parent/progeny together, generally agreeing with pedigree information. A group of 20 markers from five EST-PCR primer pairs distinguished all the genotypes in this study. These markers are as easy to generate and as affordable as RAPDs, but are based on actual gene sequences, and should have general utility for DNA fingerprinting, genetic diversity, and mapping studies.