Occurrence of Polysiphonia Epiphytes in Kappaphycus Farms at Calaguas Is., Camarines Norte, Phillippines

This paper describes the occurrence of an epiphyte infestation of Kappaphycus farms in Calaguas Is. Camarines Norte, Philippines. In particular, percentage cover of ‘goose bump’-Polysiphonia and ‘ice-ice’ disease, and some environmental parameters that influence the thallus condition of Kappaphycus alvarezii in Calaguas Is. were assessed during 3 separate visits and are discussed.Commercial cultivation of Kappaphycus at Calaguas Is. began in the early 1990s. After five years of farming, the stock was destroyed by a strong typhoon. The area was re-planted the following year and production increased annually and reached its peak in 1998–1999. However, the following year, the first occurrence of a Polysiphonia epiphyte infestation occurred concurrently with an ‘ice-ice’ disease. Consequently, annual production and the number of seaweed planters declined rapidly, and this situation persists to the present time. This paper highlights the etiological factors and their consequences.Results show that farm-site selection is critical for the success of Kappaphycus production. Characteristics of water movement and light intensity in farming areas contributed to the occurrence and detrimental effect of the phenomenon described as ‘goose bumps’: a morphological distortion of the host seaweed due to the presence of a Polysiphonia sp. epiphyte. A strong inverse correlation was observed between the occurrence of Polysiphonia and water movement: areas with low water motion registered a higher % cover (65%) of Polysiphonia than those in more exposed areas (17%). Although ‘goose bump’-Polysiphonia infestation and ‘ice-ice’ disease pose a tremendous problem to the seaweed farmers, the results of this limited assessment provide a useful baseline for future work.     

Screening of a broad range of rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) germplasm for <Emphasis Type="Italic">in vitro</Emphasis> rapid plant regeneration and development of an early prediction system

Rice has emerged as a model monocot for studies in agriculture and biotechnology due to its relatively small genome and a ready accessibility to plant material. Tissue culture is one of the tools required for genetic transformation and some breeding programs, and the selection of high-frequency regenerator types is essential for success in these technologies. Thirty-three rice entries with agricultural and biotechnological characteristics of interest were screened with the aim to identify the best regenerators. Entries that exhibited between 50% and 90% regeneration frequencies include ‘Taipei-309,’ ‘Super Dwarf,’ ‘Norin’ (japonica types), PI 312777, ‘Ali Combo’ (indica types), ‘STG-S,’ and ‘LA3’ (red rice types). One third of the entries tested were at least two times better at regeneration than the often-cited regenerator ‘Nipponbare.’ Those entries showing at least 85% frequency of greening or somatic embryo formation at 15 or 30 d on regeneration medium ultimately produced whole plants after 45 d on regeneration medium at high frequency (at least 40%); those entries not reaching the 85% threshold of greening by Days 15 or 30 exhibited moderate (15–40%) to low (less than 10%) frequency of whole plant regeneration. This greening response suggests the means for an early prediction system for identification of useful rice regenerator lines, which would be beneficial for high-throughput screening of germplasm as well as for decreasing the time and cost of in vitro culture.     

Modification of competence for in vitro response to Fusarium oxysporum in tomato cells. III. PR-protein gene expression and ethylene evolution in tomato cell lines transgenic for phytohormone-related bacterial genes

 Previous work carried out in our laboratory has shown that, in tomato, the alteration of endogenous phytohormone equilibria through the integration of Agrobacterium tumefaciens genes for auxin and cytokinin synthesis can modify the active defense response to Fusarium oxysporum f. sp. lycopersici. The susceptible cv ‘Red River’ acquires a stable competence for active defense, particularly when the phytohormone equilibrium is altered in favour of cytokinins. Here, we analyse the expression of genes involved in the defense response against pathogens, i.e. pathogenesis-related (PR)-protein genes, in the susceptible ‘Red River’ and resistant ‘Davis’ cultivars transgenic for the aforementioned genes. Fungal cell-wall components, glutathione, salicylic acid and the ethylene-forming ethephon are used as “probes” for the induction of defense processes, including ethylene production. The data obtained show that the extracellular PR-proteins (acidic chitinase and PR-1 protein) that were inducible in the control tissue of the resistant ‘Davis’ cultivar and not expressed in the susceptible ‘Red River’ cultivar became constitutive in the transgenic tissues of both. On the other hand, expression of the intracellular PR-proteins (basic chitinase and β-1,3-glucanase) was found to be constitutive in all cases, both in the control and in the transgenic cell lines of the resistant and the susceptible tomato cultivars. Ethylene production was higher in ‘Davis’ than in ‘Red River’, and significantly increased in the transgenic cell lines, particularly when cytokinin synthesis was altered. Received: 25 February 1998 / Accepted: 7 April 1998     

Callus induction and plant regeneration from broccoli (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. italica) for transformation

We evaluated the efficiency of callus induction and plantlet regeneration from hypocotyl explants of broccoli (Brassica oleracea var. italica). The cultivars were ‘Marathon’, ‘Greenbelt’, and ‘Shogun’. Transformation success was not affected by the presence of tobacco feeder-cell layers on the culture media. The frequency of shoot regeneration was greater from 10-d-old hypocotyls than from 14-d-old hypocotyls. Both ‘Marathon’ and ‘Greenbelt’ had higher potentials for tissue regeneration than did ‘Shogun’. We found that for transformation selection, the optimum concentration was either 50 mg/L kanamycin or 100 mg/L genetkin.     

Selection of Highly Informative Microsatellite Markers to Identify Pollen Donors in ‘Hass’ Avocado Orchards

‘Hass’ is the most popular avocado (Persea americana Mill.) cultivar in the world. It has been characterized as a crop requiring cross-pollination. However, the potential extent of self-pollination and the most effective pollen donors (best cross-pollinizing cultivars) have not been determined. In this study, 56 markers were screened against ‘Hass’ and nine commonly used pollinizing cultivars grown in southern California: ‘Bacon,’ ‘Ettinger,’ ‘Fuerte,’ ‘Harvest,’ ‘Lamb Hass,’ ‘Marvel,’ ‘Nobel,’ ‘Sir Prize,’ and ‘Zutano.’ Seventeen microsatellite, i.e., simple sequence repeat (SSR) markers, were found to be very promising for paternity analysis. Four highly informative SSR markers were selected to accurately and unequivocally identify pollen parents of ‘Hass’ fruit from an orchard interplanted with these pollinizing cultivars. From 2003 to 2006, 7,984 ‘Hass’ fruit were analyzed for their paternity. Overall, the pollen parents of 99.55% of the analyzed fruit could be unequivocally identified with a single multiplex polymerase chain reaction (PCR). Only 36 fruits (<0.45%) required a second PCR reaction to reach unequivocal identification of the pollen parents.     

Species of <Emphasis Type="Italic">Neohaliotrema</Emphasis> Yamaguti, 1965 (Monogenea: Ancyrocephalidae) from the pomacentrid <Emphasis Type="Italic">Abudefduf vaigensis</Emphasis> (Quoy &; Gaimard) off Pulau Langkawi,Malaysia, with a revised diagnosis of the genus and a key to its species

Four new and one unidentified species of Neohaliotrema Yamaguti, 1965 were obtained from the gills of the Indo-Pacific sergeant Abudefduf vaigensis (Quoy & Gaimard) off Pulau Langkawi, Malaysia. The five species, N. malayense n. sp., N. bombini n. sp., N. andamanense n. sp., N. parvum n. sp. and an unidentified Neohaliotrema sp. (similar to N. macracanthum Zhukov, 1976), are described and distinguished based mainly on features of the haptor. Species of this genus are divisible into two groups, the ‘maomao group’, with two pairs of morphometrically modified ‘marginal’ hooks and a fenestrated haptor, and the ‘gracile group’, with morphologically similar marginal hooks and an entire haptor. With the exception of N. bombini n. sp., the species described fit within the ‘maomao group’. It is suggested that the more complex Neohaliotrema species of the ‘maomao group’ have modified hooks 1 and 2 on a haptoral ‘isthmus’ between two large apertures, i.e. ‘windows’, whereas the less complex species lacking these features are those of the ‘gracile group’. Neohaliotrema spp. have only a single pair of pigmented eye-spots. A fenestrated haptor is unique to the Neohaliotrema spp. of the ‘maomao group’. The generic diagnosis of Neohaliotrema is amended to include new data and a key to its known species is presented.     

Molecular mapping of leaf rust resistance gene <Emphasis Type="Italic">Rph14</Emphasis> in <Emphasis Type="Italic">Hordeum vulgare</Emphasis>

An incompletely dominant gene conferring resistance to Puccinia hordei, Rph14, identified previously in an accession of Hordeum vulgare, confers resistance to all known pathotypes of P. hordei in Australia. Knowledge of the chromosomal location of Rph14 and the identification of DNA markers closely linked to it will facilitate combining it with other important leaf rust resistance genes to achieve long lasting resistance. The inheritance of Rph14 was confirmed using 146 and 106 F₃ lines derived from the crosses ‘Baudin’/‘PI 584760’ (Rph14) and ‘Ricardo’/‘PI 584760’ (Rph14), respectively. Bulk segregant analysis on DNA from the parental genotypes and resistant and susceptible DNA bulks using DArT markers located Rph14 to the short arm of chromosome 2H. DArT marker bPb-1664 was identified as having the closest genetic association with Rph14. PCR based marker analysis identified a single SSR marker, Bmag692, linked closely to Rph14 at a map distance of 2.1 and 3.8 cm in the ‘Baudin’/‘PI 584760’and ‘Ricardo’/‘PI 584760’ populations, respectively.     

Oud-leerling versus ancien élève: A Comparative Study of Adjectives Grammaticalizing into Prefixes in Dutch and French

This article analyzes the grammaticalization of adjectives into prefixes in Dutch and French. In the first part, the notion of ‘affixoids’, hybrid elements that combine properties of free lexemes and bound morphemes, will be defined and illustrated. It will be claimed that affixoids can be seen as a result of a grammaticalization process for which we will advance phonological, morphological, semantic and distributional parameters applying to the evolution of adjectives into prefixes. The second part will be devoted to a specific case study in which these grammaticalization parameters will be applied to the Dutch adjectives oud ‘old’ and nieuw ‘new’ and their French counterparts ancien ‘old’ and nouveau ‘new’ when used in word-formation. More particularly, we will examine whether these adjectives may develop prefix-like properties when embedded in a compound structure and determine their degree of grammaticalization. Kristel Van Goethem is a Postdoctoral fellow of the Research Foundation-Flanders (FWO)     

Inflammation,Aging, and Cancer: Tumoricidal Versus Tumorigenesis of Immunity

Acute inflammation is a highly regulated defense mechanism of immune system possessing two well-balanced and biologically opposing arms termed apoptosis (‘Yin’) and wound healing (‘Yang’) processes. Unresolved or chronic inflammation (oxidative stress) is perhaps the loss of balance between ‘Yin’ and ‘Yang’ that would induce co-expression of exaggerated or ‘mismatched’ apoptotic and wound healing factors in the microenvironment of tissues (‘immune meltdown’). Unresolved inflammation could initiate the genesis of many age-associated chronic illnesses such as autoimmune and neurodegenerative diseases or tumors/cancers. In this perspective ‘birds’ eye’ view of major interrelated co-morbidity risk factors that participate in biological shifts of growth-arresting (‘tumoricidal’) or growth-promoting (‘tumorigenic’) properties of immune cells and the genesis of chronic inflammatory diseases and cancer will be discussed. Persistent inflammation is perhaps a common denominator in the genesis of nearly all age-associated health problems or cancer. Future challenging opportunities for diagnosis, prevention, and/or therapy of chronic illnesses will require an integrated understanding and identification of developmental phases of inflammation-induced immune dysfunction and age-associated hormonal and physiological readjustments of organ systems. Designing suitable cohort studies to establish the oxido-redox status of adults may prove to be an effective strategy in assessing individual’s health toward developing personal medicine for healthy aging.     

Sequence Analysis and Comparison of 16S rRNA, 23S rRNA and 16S/23S Intergenic Spacer Region of Greening Bacterium Associated with Yellowing Disease (Huanglongbing) of Kinnow Mandarin

High incidence (up to 40%) of symptoms of yellowing and yellow mottling was observed in 5–8 years old orchards of kinnow mandarin {Citrus reticulate Balanco (‘King’ × ‘Willow mandarin’)} in the Punjab state of India during a survey in January 2007. These symptoms are often confused with nutrient deficiency and other stress related disorders. However, a greening bacterium has been attributed to cause the disease. The disease was graft transmissible and sequencing of 16S rRNA, 16S/23S intergenic spacer region and 23S rRNA of the greening bacterium associated with yellowing disease in kinnow mandarin confirmed it to be Candidatus Liberibacter asiaticus (‘Ca L. asiaticus’) showing maximum identity of 95.9% with ‘Ca L. asiaticus’ from USA and Brazil in 16S rRNA. The study indicates definite association of ‘Ca L. asiaticus’ with yellowing/chlorotic mottling symptoms of greening disease of kinnow mandarin in Punjab state of India.     

Flower Bud Culture of Shallot (Allium cepa L. Aggregatum group) with Cytogenetic Analysis of Resulting Gynogenic Plants and Somaclones

Unpollinated flower culture was applied for induction of gynogenesis and somatic organogenesis in three shallot strains, ‘Dili-white’, ‘Yogya’ and ‘Dili-red’, from Indonesia. Chromosome surveys were performed on the plants obtained. From a total of 6,812 flowers, 89 plantlets were obtained by gynogenesis, of which 10 could be acclimated. Most of the plantlets were induced from ‘Dili-white’. Of the gynogenetic plants examined, two were haploid (2n = 8), four were naturally doubled haploid (2n = 16) and the remaining four were mixoploid (2n = 8, 16 or 2n = 16, 32, 64). ‘Dili-red’ showed the highest frequency of somatic organogenesis. Fifty-nine directly regenerated plants and 293 callus-derived plants were obtained from somatic organogenesis from the cultured flowers. Based on the chromosome number, frequencies of somaclonal variation were high both in the directly regenerated plants and the callus-derived plants. The frequency of tetraploid plants (2n = 32) in the former (50%) was higher than in the latter (33%). From these results we conclude that unpollinated flower culture is an effective method for chromosome doubling simultaneously with haploid induction in shallot.     

Isoenzyme markers in varietal identification of banana

Summary Salt-soluble polypeptide and a few isozymes were profiled to identify banana cultivars available in Andamans, India. Salt-soluble polypeptide profile was found to be inappropriate in cultivar identification However, isozymes such as peroxidase could differentiate ‘Jungli kela’, ‘Tissue Cultured Dwarf Cavendish’ (TCDC), ‘Lal kela’, ‘Rajbel’, and ‘Baratang wild’, while esterase identified all the cultivars except ‘Rajbel’ and ‘Tarkari kela’. The latter two cultivars could be identified with the use of malate dehydrogenase (MDH) and peroxidase profiles, MDH portrayed cultivar-specific distinct banding pattern in ‘Khatta Champa’, ‘Tarkari kela’, and ‘Baratang wild’, ‘China kela’ could be identified easily by superoxide dismutase (SOD). Amongst four isozymes, esterase was found to be most efficient in identifying eight cultivars amongst 10; bence this isozyme may be used often as a marker for cultivar identification of banana.     

Axillary proliferation and tuberisation of Dioscorea cayenensis–D. rotundata complex

Yams (Dioscorea spp) are tuber crops used as staple food in Africa because of their nutritional value. However agronomic constraints, phytosanitary problems and the lack of good healthy planting material restrict their production. In contrast to the inefficiency of traditional method of planting, tissue culture techniques allow to increase the multiplication and the rapid production of pathogen- free plant material. This work was undertaken to provide farmers in African countries with healthy microplants and microtubers as seeds. In vitro nodal segments of two varieties of local yams D. cayenensis–D. rotundata complex (cv. ‘Singo’, cv. ‘Singou’ and cv. ‘Gnidou’) were micropropagated on the modified medium of Murashige and Skoog. The morphogenesis, the growth of microplants and microtuber formation have been found to be controlled by external factors that act individually and synergistically. Addition of kinetin (2 mg l⁻¹) to the culture media could reduce multiplication rate (node number) of some clones. An increase of the sucrose concentration from 3% to 5% induced no change in the multiplication and tuberisation parameters. An important reduction of the multiplication (shoot number, height and node number) and the tuberisation (tuber number and length) was observed with 8% sucrose. Multiplication (shoot and node number) was increased in the presence of jasmonic acid (10 μM). JA also induced an increase of tuber number in the absence of Kin. Multiplication of yam by in vitro growth of nodal segments is a way for rapid clonal multiplication and could allow solving the problem of lack of seed material faced by farmers. This method could also be used for multiplication of elite cultivars, independently of the growing season.     

Multiple mating in the ant Cataglyphis cursor: testing the sperm limitation and the diploid male load hypotheses

Multiple mating (i.e., polyandry) by queens in social Hymenoptera is expected to weaken social cohesion since it lowers within-colony relatedness, and hence, indirect fitness benefits from kin selection. Yet, there are many species where queens mate multiply. Several hypotheses have been put forward to explain the evolution and maintenance of polyandry. Here,we investigated the ‘sperm limitation’ and the ‘diploid male load’ hypotheses in the ant Cataglyphis cursor. Genetic analyses of mother-offspring combinations showed that queens mate with up to 8 males, with an effective mating frequency of 3.79. Significant paternity skew (unequal contribution of the fathers) was detected in 1 out of 5 colonies. The amount of sperm stored in the spermatheca was not correlated with the queen mating frequency, and males carry on average enough sperm in their seminal vesicles to fill one queen’s spermatheca. Analyses of the nuclear DNA-content of males also revealed that all were haploid. These results suggest that the ‘sperm limitation’ and the ‘diploid male load’ hypotheses are unlikely to account for the queen mating frequency reported in this ant. In light of our results and the life-history traits of C. cursor, we discuss alternative hypotheses to account for the adaptive significance of multiple mating by queens in this species. Received 13 August 2008; revised 19 November 2008; accepted 21 November 2008.     

Response of durum wheat cultivars to immature embryo culture,callus induction and in vitro salt stress

Response of twenty eight cultivars of durum wheat (Triticum turgidum var. durum) to immature embryo culture, callus production and in vitro salt tolerance was evaluated. For assessment of cultivars to salt tolerance, growing morphogenic calli were exposed to different concentrations of NaCl (0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8 and 2.1% w/v) added to the culture medium during two subsequent subcultures (4 weeks each). Comparison of cultivars for callus induction from immature embryo was based on callus induction frequency and fresh weight growth of callus (FWG). While, for salt tolerance, the relative fresh weight growth (RFWG) and necrosis percent of callus were used. There were significant differences among cultivars for potential of regeneration from immature embryo, and ‘Shahivandi’ a native durum wheat cultivar originating from western Iran was superior among the cultivars tested. The FWG distinguished cultivars more than callus induction frequency did for callus induction evaluation. Hence, a range of FWG from 1.23 to 14.65 g was observed in ‘Mexical-75’ and ‘Omrabi-5’ cultivars, respectively. Growing calli derived from cultivars ‘PI 40100’ and ‘Dipper-6’ showed superiority for tolerating salinity under in vitro conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

What do the basal ganglia do? A modeling perspective

Basal ganglia (BG) constitute a network of seven deep brain nuclei involved in a variety of crucial brain functions including: action selection, action gating, reward based learning, motor preparation, timing, etc. In spite of the immense amount of data available today, researchers continue to wonder how a single deep brain circuit performs such a bewildering range of functions. Computational models of BG have focused on individual functions and fail to give an integrative picture of BG function. A major breakthrough in our understanding of BG function is perhaps the insight that activities of mesencephalic dopaminergic cells represent some form of ‘reward’ to the organism. This insight enabled application of tools from ‘reinforcement learning,’ a branch of machine learning, in the study of BG function. Nevertheless, in spite of these bright spots, we are far from the goal of arriving at a comprehensive understanding of these ‘mysterious nuclei.’ A comprehensive knowledge of BG function has the potential to radically alter treatment and management of a variety of BG-related neurological disorders (Parkinson’s disease, Huntington’s chorea, etc.) and neuropsychiatric disorders (schizophrenia, obsessive compulsive disorder, etc.) also. In this article, we review the existing modeling literature on BG and hypothesize an integrative picture of the function of these nuclei.     

Bacteria of muds colonized bySpartina townsendii and their possible role in Spartina die-back

Summary A study of the bacterial microflora of muds colonized bySpartina townsendii agg. in healthy and ‘die-back’ sites in the Lymington estuary was made. No important qualitative differences were found between the microfloras of the two types of site. Fewer species, however, were present in the die-back sites. It is suggested that under anaerobic conditions, such as occur in a ‘die-back’ site, the bacteria will utilise such oxygen as is present, and will then engage in anaerobic metabolic processes, producing reduced ions which will reduce the oxidation-reduction potential still further. The occurrence of abundant sulphate reducers in the ‘die-back’ sites may be particularly significant in this respect. No evidence was obtained of any more direct relationship between bacterial flora and the development of ‘die-back’.     

Resistance to <Emphasis Type="Italic">Erysiphe necator</Emphasis> in the grapevine ‘Kishmish vatkana’ is controlled by a single locus through restriction of hyphal growth

Vitis vinifera ‘Kishmish vatkana’, a cultivated grapevine from Central Asia, does not produce visible symptoms in response to natural or artificial inoculation with the fungus Erysiphe necator Schwein., the casual agent of powdery mildew. ‘Kishmish vatkana’ allowed pathogen entry into epidermal cells at a rate comparable to that in the susceptible control Vitis vinifera ‘Nimrang’, but was able to limit subsequent hyphal proliferation. Density of conidiophores was significantly lower in ‘Kishmish vatkana’ (33.6 ± 8.7 conidiophores mm⁻²) than in ‘Nimrang’ (310.5 ± 24.0 conidiophores mm⁻²) by 120 h after inoculation. A progeny of 310 plants from a ‘Nimrang’ × ‘Kishmish vatkana’ cross were scored for the presence or absence of visible conidiophores throughout two successive seasons. Phenotypic segregation revealed the presence of a single dominant allele termed Resistance to Erysiphe necator 1 (REN1), which was heterozygous in ‘Kishmish vatkana’. A bulked segregant analysis was carried out using 195 microsatellite markers uniformly distributed across the entire genome. For each marker, association with the resistance trait was inferred by measuring in the bulks the ratio of peak intensities of the two alleles inherited from ‘Kishmish vatkana’. The phenotypic locus was assigned to linkage group 13, a genomic region in which no disease resistance had been reported previously. The REN1 position was restricted to a 7.4 cM interval by analyzing the 310 offspring for the segregation of markers that surrounded the target region. The closest markers, VMC9H4-2, VMCNG4E10-1 and UDV-020, were located 0.9 cM away from the REN1 locus. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Accumulation of additive effects generates a strong photoperiod sensitivity in the extremely late-heading rice cultivar ‘Nona Bokra’

Many rice cultivars that originated from lower-latitude regions exhibit a strong photoperiod sensitivity (PS) and show extremely late heading under long-day conditions. Under natural day-length conditions during the cropping season in Japan, the indica rice cultivar ‘Nona Bokra’ from India showed extremely late heading (202 days to heading) compared to the japonica cultivar ‘Koshihikari’ (105 days), from Japan. To elucidate the genetic factors associated with such extremely late heading, we performed quantitative trait locus (QTL) analyses of heading date using an F₂ population and seven advanced backcross progeny (one BC₁F₂ and six BC₂F₂) derived from a cross between ‘Nona Bokra’ and ‘Koshihikari’. The analyses revealed 12 QTLs on seven chromosomes. The ‘Nona Bokra’ alleles of all QTLs contributed to an increase in heading date. Digenic interactions were rarely observed between QTLs. Based on the genetic parameters of the QTLs, such as additive effects and percentage of phenotypic variance explained, these 12 QTLs are likely generate a large proportion of the phenotypic variation observed in the heading dates between ‘Nona Bokra’ and ‘Koshihikari’. Comparison of chromosomal locations between heading date QTLs detected in this study and QTLs previously identified in ‘Nipponbare’ × ‘Kasalath’ populations revealed that eight of the heading date QTLs were recognized nearby the Hd1, Hd2, Hd3a, Hd4, Hd5, Hd6, Hd9, and Hd13. These results suggest that the strong PS in ‘Nona Bokra’ was generated mainly by the accumulation of additive effects of particular alleles at previously identified QTLs.     

Hybrid origin of some ornamentals of Allium subgenus Melanocrommyum verified with GISH and RAPD

 Random amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) methods have been used to verify the hybridogenic origin and to identify the parental species of some ornamental cultivars in the subgenus Melanocrommyum of the genus Allium. The cultivars had been selected from seed obtained after uncontrolled pollination in breeders’ fields. The combination of GISH analysis with RAPD markers is very suitable for testing the hybridogenic origin of plants and to ascertain the parental species of the hybrids in such cases. As suspected, A. macleanii and A. cristophii are the parental species of ‘Globemaster’. The parental species of cultivar ‘Globus’ are A. karataviense and A. stipitatum, and not A. cristophii and A. giganteum as has been assumed on morphological grounds. Cultivars ‘Lucy Ball’ and ‘Gladiator’ are of hybrid origin, though only one of the parental species, A. hollandicum, could be confirmed. The cultivars ‘Purple Sensation’, ‘Mount Everest’, ‘White Giant’, ‘Michael H. Hoog’ and ‘Mars’ are not hybrids since neither GISH nor RAPD suggest the presence of a second genome. ‘Purple Sensation’ belongs to A. hollandicum, ‘Mount Everest’, ‘White Giant’ and ‘Mars’ to A. stipitatum,‘Michael H. Hoog’ to A. rosenorum. Received: 3 July 1997 / Accepted: 9 October 1997