Search

Humiria balsamifera (Aubl), commonly known as “mirim”, is a plant of the Humiriaceae family, which consists of 39 species divided between eight genera: Duckesia, Endopleura, Humiria, Humiriastrum, Hylocara, Sacoglottis, Schistostemon, and Vantenea. This study aimed to characterize H. balsamifera extracts by LC-MS/MS and evaluate their antimicrobial potential through in vitro and in vivo assays. The leaves and stem bark of H. balsamifera were collected and dried at room temperature and then ground in a knife mill. The extracts were prepared with organic solvents in order to increase the polarity index (hexane, ethyl acetate, and methanol). The antimicrobial effects of these extracts were evaluated against the following bacterial strains: Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 15313, Salmonella enterica Typhimurium ATCC 14028, and Staphylococcus aureus ATCC 6538. The best activity was observed in the ethyl acetate (EALE = 780 µg/mL), methanol (MLE = 780 µg/mL), and hexane (HLE = 1560 µg/mL) leaf extracts against S. aureus. Considering the results for both antimicrobial and antibiofilm activities, the EALE extract was chosen to proceed to the infection assays, which used Tenebrio molitor larvae. The EALE treatment was able to extend the average lifespan of the larvae (6.5 days) in comparison to S. aureus-infected larvae (1 day). Next, the samples were characterized by High-Performance Liquid Chromatography coupled to a mass spectrometer, allowing the identification of 11 substances, including seven flavonoids, substances whose antimicrobial activity is already well-reported in the literature. The number of bioactive compounds found in the chemical composition of H. balsamifera emphasizes its significance in both traditional medicine and scientific research that studies new treatments based on substances from the Brazilian flora.

The race structure and genotypic diversity of four Leptosphaeria maculans populations isolated from Brassica oleracea (broccoli, cauliflower, cabbage, etc.) in central Mexico (Aguascalientes, Guanajuato and Zacatecas states) were analysed. Race structure was characterized by an unusually low diversity at three locations out of four. Fourteen minisatellite markers revealed a high proportion of repeated multilocus genotypes in these populations, combined with a significant linkage disequilibrium and strong clonal fraction (65‐87%). The occurrence of the mating-type idiomorphs always significantly departed from the 1:1 proportion expected in the case of random mating. Each population thus consists of a few (four to nine) multilocus genotypes which are specific to each location. These data strongly support the hypothesis of exclusive, or a high rate of, clonal multiplication. Comparison of cropping practices between B. oleracea and B. napus indicate that the shift in reproductive behaviour of the fungus is chiefly man-mediated.

Portuguese perennial kale is a rare leafy vegetable and forage crop in Portugal. It may be a relic of a primitive kale form which could have been grown on a large scale in Portugal and in West Europe. This kale has strong branching habit with rosettes of leaves in the stems. It shows a strongly reduced flowering ability and for this reason is vegetatively propagated. In the past, perennial kale has probably been widely distributed in West Europe, but the crop has gradually declined in occurrence in this area. At present it is an almost extinct vegetable crop and by this reason deserves to be preserved.

Breeding is probably as old as agriculture itself. Early vegetable breeders developed landrace cultivars by selection of favorable variations in horticultural traits, yield and resistance to diseases and other problems. Later new breeding methods were developed, including hybridization techniques, culminating with the use of recently developed molecular tools, all leading to our modern improved vegetable cultivars. Great emphasis on protection of cultivars by seed companies, including development of F1 hybrids, plant cultivar protection and patenting have been done. There were 392 vegetable crops cultivated worldwide but only slightly over one half of the total number of them have attracted commercial breeding attention. In recent times, there have been challenges and new trends in the breeding domain. These include an unrelenting movement away from well supported public breeding institutions to a breeding world dominated by private entities, and an increase in size of the companies in the private sector, with emphasis on the major vegetable crops. Almost half of the world vegetable farmers are poor and cannot afford to buy hybrid seed every growing season. Their economics and logistics make them difficult to buy expensive improved or hybrid cultivars since the lack of capital by subsistence farmers denies them the opportunity to invest in vegetable production inputs. If credit facilities and other input facilities are offered, improved or hybrid cultivars can have also a great impact on subsistence vegetable farmers overcoming their poverty and food insecurity. In last 50 years vegetable genetic resources are being lost, on a global scale at the rate of 1–2% per year. The multinational seed companies concentration in huge corporations have merged or canceled some vegetable breeding programs to reduce costs. Then there will be fewer vegetable breeders in the future and the growers will be dependent on a narrower genetic background, that could contribute in a near future, for food insecurity. Smaller seed companies, which are usually specialize in few vegetable crops, must be supported, possibly through autonomous affiliation with the larger companies. There is a need of investment in research breeding and cultivar development in traditionally open-pollinated cultivars and in the minor and so-called “forgotten” vegetables. More investments in this area will mean cheaper cultivars for growers to choose from and more preservation of vegetable biodiversity. In recent years, private plant breeding programs have increased in size and number. Financial investment also increased, as well as interest in intellectual property protection. Protective measures, especially patenting, must be moderated to eliminate coverage so broad that it stifles innovation. The intellectual property protection laws for plants must be made less restrictive to encourage research and free flow of materials and information. Public sector breeding must remains vigorous, especially in areas where the private sector does not function. This will often require benevolent public/private partnerships as well as government support. Intellectual property rights laws for plants must be made less restrictive to encourage freer flow of materials. Active and positive connections between the private and public breeding sectors and large-scale gene banks are required to avoid a possible conflict involving breeders’ rights, gene preservation and erosion. Improved and hybrid vegetable cultivars are, and will continue to be, the most effective, environmentally safe, and sustainable way to ensure global food security in the future.

There is no information in the literature about the variability of resistance of Chinese Brassica vegetables, pak choi and Chinese cabbage, to the white blister disease caused by Albugo candida (Pers.) Kuntze. A collection of 43 accessions of pak choi and 19 accessions of Chinese cabbage was screened for resistance to the Portuguese A. candida isolate Ac 506 at the cotyledon stage. Different levels of resistance were found among the germplasm tested, ranging from complete resistance to full susceptibility. Most of the accessions were highly susceptible with less than 10% of resistant seedlings, and only four accessions of pak choi, presenting more than 50% resistant seedlings, were considered as new sources or resistance to white blister. Inheritance of resistance at the cotyledon stage was studied in two crosses between the most resistant pak choi accession, BRA 117, and the highly susceptible rapid cycling Brassica rapa line CrGC 1.19. It was proposed that resistance to white blister in pak choi BRA 117 is controlled by two nuclear genes with dominant recessive epistatic gene action.

The identification of seedling resistance to white rust of crucifers was performed in a screening of a B. oleracea core collection with 400 accessions representing the genetic and geographic diversity of the species. Fifty seedlings per accession were tested against the Portuguese isolate Ac502 using the methodology and evaluation procedures developed by and . The percentage of resistant seedlings (%R) and the conventional rating criteria of the mean Disease Index (DI) based on the two different evaluation procedures of disease expression used, were compared and adopted as the criteria to rank the accessions for their interest as sources of resistance. A great variability of reactions was found between and within accessions of the core collection, ranging from complete resistance to full susceptibility. Sources of resistance were found namely among the cauliflowers, broccoli and tronchuda cabbages gene pools. Forty-seven accessions presented at least 20% of resistant seedlings. Nine accessions (the kales INRA18 and INRA62, the cauliflowers HRI4856, HRI4866 and HRI5424, the loose-head cabbage HRI11555, the savoy cabbage BRA848, the black broccoli HRI6318 and the Portuguese tronchuda cabbage ISA207) presented 50–78% of resistant seedlings and so they should be considered as potential and useful sources for direct use in breeding programs for white rust resistance. Fourteen inbred lines, representing the full range of disease expression, derived from resistant accessions of the core collection were also tested for resistance to other two Portuguese isolates (Ac503 and Ac504) and to a UK isolate. The results provided no evidence of differential reaction to the A. candida isolates tested.

Two experiments were performed in order to determine the effect of medium renovation and incubation temperature regimes on in vitro microspore culture embryogenesis in four tronchuda cabbages. In the first experiment, the effect of medium renovation of microspore culture after 0, 24, 48, 72, 96 and 120 h, on embryo production was studied. A decrease of embryo yields with medium refreshing was always observed in the tronchuda cabbages ‘Couve Grelo’, ‘Penca da Povoa’ and ‘Couve Algarvia’, while an increase of the embryo yields with the transference of microspores to a fresh medium after 24 h was observed on the ‘Penca de Mirandela’. With the ‘Couve Algarvia’, a thorough analysis of each of the seven donor plants allowed their separation into five different groups. In one of the group, the control, without medium renovation, gave the best production of embryos. In the other, it was the treatment of medium renovation after 24, 48, 72 and even at 96 h that produced the most embryos. In all the accessions, and especially in the ‘Couve Algarvia’, qualitative improvement of embryo development into plantlets was also observed with the renovation of the media after 48, 72 and 96 h. In the second experiment, the effect of incubation regimes at 27.5 and 30 °C for 2 days, and 32.5 and 35 °C for 1 and 2 days, on embryo production was studied. Embryo yields were significantly higher in the ‘Couve Grelo’, ‘Penca da Povoa’ and ‘Penca de Mirandela’ when using the standard microspore incubation at 30 °C for 2 days. In contrast, the ‘Couve Algarvia’ embryo yield was significantly higher at 32.5 °C for 1 day compared to the standard 30 °C for 2 days. In this accession, with a higher proportion of embryogenic bicellular pollen, a temperature stress treatment of 30 °C for 2 days was insufficient to induce cellular divisions in microspores.

Conditions for reliable induction of embryogenesis from isolated microspores were studied in ten genotypes of broccoli. Embryo yields were significantly increased in almost all of the broccoli genotypes by the incubation at 32.5 °C for 1 day, than when the standard incubation at 30 °C for 2 days was used. Treatments of 48 hours at 32.5 °C produced less than optimal results suggesting that broccoli microspores are more sensitive to high temperatures than those of B. napus. The use of the 1/2 NLN-13 medium yielded greater number of embryos than the standard NLN-13. The magnitude of the response to the redution of the concentration of major salts by half in the NLN medium varied with the different genotypes. High embryogenic broccoli cultivars, such as ‘Shogun’, ‘SDB9’, and ‘Green Valiant’, presented a better response to the reduction of the concentration of major salts by half in NLN-13. Reduction never produced a detrimental effect on embryo yield and seems not to have any effect in the subsequent development of embryos in plants.

The effect of three concentrations of silver nitrate on anther culture embryo production was studied in 27 morphotypes of Brassica oleracea. Embryo yields were significantly increased in the majority of the morphotypes by the addition of silver nitrate to the media. Embryo yields were not increased in only a few of the almost nonembryogenic accessions. The magnitude of the response to silver nitrate varied with the different morphotypes. In general, the best results were obtained with the addition of 10 mg l ˇ1 AgNO3. Without the addition of silver nitrate no embryos would have been obtained in some of the nonembryogenic morphotypes. Data suggests that silver nitrate addition to anther culture media promoted embryo production in different B. oleracea morphotypes. # 1999 Elsevier Science B.V. All rights reserved.

The effect of the addition of a 0.1 ml drop of activated charcoal (AC) on microspore culture embryogenesis was studied in nine morphotypes of Brassica oleracea. Embryo yields were significantly increased in all of the morphotypes by the addition of the 0.1 ml drop of AC to the microspore culture media. The magnitude of the response to the addition of AC varied with the different plants and morphotypes. The addition of AC never produced a detrimental effect. A qualitative improvement of the subsequent development of embryos to plants was also observed with the addition of AC. Data suggest that the addition of AC to microspore culture media promoted embryo production in different B. oleracea morphotypes.

Twenty-nine Brassica oleracea accessions, including Portuguese cole landraces, were screened for resistance to crucifer downy mildew using seven Portuguese isolates of Peronospora parasitica. Seven-day-old seedlings were inoculated on the cotyledons with two 10 μl droplets of a water suspension containing 5 × 105 conidiospores ml−1. Host-pathogen interaction phenotype (IP) was evaluated 7 days after inoculation using an increasing susceptibility (1–9) scale. The screening revealed high variable reaction for downy mildew resistance within Portuguese cole landraces. Some accessions were very susceptible with most of the plants scoring in IP classes 7 and 9, but most of the accessions showed high variability in interaction phenotype with plants scoring in all IP classes. Four accessions belonging to landraces ‘Couve Algarvia’, ‘Couve Murciana’ and ‘Couve Coracao de Boi’ expressed high resistance to all downy mildew isolates, with over 42% of seedlings in the non-sporulating IP class 1. Downy mildew isolates Pp504 (Batalha), Pp503 (Condeixa), and Pp507 (Faro) showed slightly higher aggressiveness than isolates Pp505 (Loures), Pp502 (Vila Real), Pp506 (Odemira), and Pp501 (Povoa). There was no significant interactions between accession and downy mildew isolate, which shows that the geographic origin of the host and pathogen had no influence on the interaction phenotype. This study confirms the high potential of Portuguese cole landraces as sources of resistance to downy mildew and has identified accessions with a high valuable resistance.

Portuguese coles, tronchuda cabbage and galega kale landraces, are a unique group of vegetables very important for Portuguese horticulture owing to their excellent adaptation to prevalecent climatic conditions and good integration in the traditional small farming cropping systems. Reports on these coles are scarce and scattered. A bibliography review is presented on some general aspects of Portuguese cole landraces such as botany, folknames, foreign synonymy, origin, history, and worldwide spreading. In addition to such available information, other data has been gathered from growers in door-to-door enquiries during a germplasm collecting of Portuguese coles. Recent research on the taxonomy of Portuguese coles has been summarized.

Isozyme analysis was used to study the genetic variation and the genetic relationships of a collection of 48 Brassica spp. including 31 Portuguese coles (Brassica oleracea L.) accessions representative of the different landraces cultivated in Portugal. Other brassicas included in this experiment were Jersey kale, kailaan, common cabbages, broccolis, cauliflower, nine-chromosome wild brassica and turnip. Nine enzymes used in the starch gel electrophoresis included: PGM, PGI, AAT, LAP, TPI, FBP, SOD, IDH and GR. Twenty-one putative loci were revealed, with 3 showing invariance and the other 18 contained 50 alleles. The allelic frequencies at these loci represented by 40 plants per accession were used to calculate the following estimators of genetic variation: % of polymorphic loci, average number of alleles per polymorphic loci, average number of alleles per locus, and index of heterozygosity. The genetic relationships were evaluated considering Nei (1978) and Rogers (1972) genetic distances between each pair of accessions whose matrices were hierarchically clustered by the UPGMA method. The accessions were also studied using the principal coordinate analysis. Portuguese Tronchuda cabbages and Galega kales have shown high genetic diversity in comparison with the other accessions. This indicates their potential variation for use in breeding programs. The UPGMA results show that the 48 accessions, with the exception of B. insularis, B. cretica, and turnip, can be clustered into 6 groups: (a) Portuguese Tronchuda cabbages, Galega kales and Algarve cabbages; (b) common cabbages and kales; (c) Couve Poda do Algarve and broccoli; (d) Algarve cabbage and common cabbages; (e) kailaan; (f) broccoli and cauliflower. The groupings obtained by the isozyme analysis are difficult to interpret considering the origin of the Brassica spp. and the morphological resemblance among the accessions.

Morphological characters, nuclear RFLPs, and isozyme analysis were used to study the similarity between 32 Portuguese Tronchuda cabbage and Galega kale landraces, and some cabbage cultivars traditionally grown in Portugal. Forty-six morphological characters observed in two consecutive years, RFLP data from 55 nuclear probes, detecting 291 polymorphic nuclear DNA restriction fragments, and allelic frequencies in 21 putative loci, generated by nine isozymes, were analyzed by the unweighted pair group method, using arithmetic averages (UPGMA), in order to present the results in the form of a phenogram. The three methods resulted in different clustering patterns of the 32 cole accessions. Morphological characters gave consistent clustering according to the traditional landrace definition and denomination, producing clear separation between Tronchuda cabbages and Galega kales. RFLPs were unable to separate Tronchuda cabbages from Galega kales and defined five landrace groups corresponding to their geographic origins rather than to their morphological similarities. Isozymes showed poor accession discrimination and an intermediate clustering pattern with some accessions being clustered according to their geographic origins and others according to their morphological similarities. Portuguese Tronchuda cabbages and Galega kales constitute a distinct and relatively homogenous group within Brassica oleracea, sharing the same genetic background. It is concluded that Portuguese coles have evolved independently from a common ancestor to the present cultivated forms. Portugal should be considered as an important region of domestication of specialized leafy coles.

Forty-four landraces of Portuguese coles (Brassica oleracea L.), representing different morphotypes, were screened at the cotyledon stage for downy mildew resistance, caused by Peronospora parasitica. Two isolates of the pathogen, PHW 630 and PHW 828, were used in the experiment. The mean disease interaction phenotype varied among the landraces. Overall, the Portuguese coles have shown resistance to both isolates, particularly to isolate PHW 828. Some landraces were identified with differential reaction to the two P. parasitica isolates. Some of the Portuguese coles are, therefore, good sources of resistance genes to P. parasitica, and could be used in breeding programs or in the development of a downy mildew host differential set. Among the morphotypes tested, Couve Algarvia (ISA 207), Couve Galega (ISA 243 and 187) and Couve Gloria de Portugal (ISA 84) have presented the highest resistance interaction. For the development of host differential sets, the landraces ISA 2 (Penca de Mirandela), ISA 35 (Couve de Valhascos) and ISA 600 (Penca Espanhola) could be further selected for the differentiation of P. parasitica isolates. They are resistant to PHW 828 and susceptible to PHW 643. The same morphotypes and landraces were also screened at the seedling stage for resistance to clubroot, caused by Plasmodiophora brassicae Woron.. Although some variation for resistance could be noticed in some the landraces tested, mainly Galega kale types, none of them presented a sufficient level of resistance as to be directly be useful in breeding for resistance to race 6 of P. brassicae.

Summary Fifty-six landraces of Portuguese coles (Brassica oleracea L.),representing fourteen morphotypes, were screened for resistance to Leptosphaeria maculansat the cotyledon stage . Three isolates of the pathogen belonging to three pathogenicity groups were used in the screening . The mean disease interaction phenotype of theB. oleracea landraces with the L. maculansisolates confirmed their differences in pathogenicity . When compared to pathogenicity grouping using a B. napus differential set, a different classification was observed on B. oleracea for the three L. maculansisolates, suggesting possible differences in the genetic interaction between the two plant species and the pathogen . Most of the Portuguese cole landraces were found to be susceptible to all three isolates of L. maculans,although a few have shown intermediate interaction pheno

RFLPs were used to study the genetic relationships of 31 Portuguese coles (Brassica oleracea L.) representing the different ecotypes or landraces grown in Portugal. Other cole crops such as Jersey kale, Chinese kales, common cabbages, broccolis and cauliflower, two nine-chromosome wild species, and one accession of turnip also were included to determine the evolutionary relationships of Portuguese coles to other related coles. Principal coordinates and cluster analyses were conducted using a package of computer programs and RFLP data from 55 nuclear DNA probes, detecting 291 polymorphic restriction fragments. The results showed that the 48 accessions clustered into five groups: (a) a dispersed group with turnip and the wild brassicas; (b) Chinese kales; (c) broccolis and cauliflower; (d) a disperse group including Algarve and Jersey kales, thousand head kale, cabbages, and savoy cabbage; (e) a large and compact group containing all Portuguese tronchuda cabbages and kales. This unique and closely related group containing Portuguese tronchuda cabbages and kales could be further divided into five subgroups corresponding to the major areas of cultivation. The phenetic groupings of Portuguese tronchuda cabbages and kales based on RFLP data corresponded more with their geographic origins (collecting sites) than with their morphological similarities. A mechanism involving geographic isolation and frequent intercrossing within local areas is proposed to explain genetic relationships among Portuguese tronchuda cabbages and kales.

The most common and effective way to control phoma stem canker (blackleg) caused by Leptosphaeria maculans in oilseed rape (Brassica napus) is through the breeding of resistant cultivars. Race specific major genes that mediate resistance from the seedling stage have been identified in B. napus or have been introgressed from related species. Many race specific major genes have been described and some of them are probably identical in B. napus (allotetraploid AACC) and the parental species B. rapa (diploid AA). More work is needed using a set of well-characterised isolates to determine the number of different major resistance genes available. In some B. napus cultivars, there is resistance which is polygenic (mediated by Quantitative Trait Loci) and postulated to be race non-specific. Many of these major genes and Quantitative Trait Loci for resistance to L. maculans have been located on B. napus genetic maps. Genes involved in race specific and polygenic resistance are generally distinct.

Twelve accessions of tronchuda cabbage landraces were tested for their ability to produce embryos through microspore culture in NLN-13 medium. A sample from all the isolations was stained with DAPI for determination of microspore developmental stage. The relationship between the microspore developmental stage and the production of microspore-derived embryos was evaluated.\ud Embryos were obtained from all the accessions. Considerable variation was observed between isolations with different developmental stage of microspores, accessions and plants within the same accession. The best embryogenic responses occurred in microspore populations with approximately 10 to 89% of binucleate pollen. The highest embryo yield was obtained with one of the ‘Couve de Valhascos’ accessions (0.41 embryos / 1 000 microspores) and the lowest yields with the accessions of ‘Couve Portuguesa’ (less than 0.07 embryos / 1 000 microspores).

The objective of this project is to conduct a systematic evaluation of the distribution of diversity in Brassica oleracea with respect to resistance to three important parasites: Peronospora parasitica (downy mildew), Albugo candida (white blister) and Brevicoryne brassicae (cabbage aphid). A core collection of approximately 400 accessions representing the geographical, morphological and physiological diversity of the species has been selected for study. Protocols have been established to allow the rapid evaluation of phenotypic variation for response to all parasites and primary screening of the core collection is well advanced. Resistant individuals are being selected from within accessions expressing a high frequency of resistance. These are being crossed with a uniformly susceptible, self-compatible, rapid-cycling line to facilitate genetic characterisation and potentially easy gene-banking. Several putative new sources of resistance have been identified. Data will be linked to the European Brassica Database and together with seed will be made freely available to breeders and other researchers.

A morphological study was carried out to determine the relationships among Portuguese cole landraces using 58 accessions belonging to: (i) Portuguese Tronchuda cabbage (Brassica oleracea var. tronchuda Bailey syn. var. costata De Candolle, Couve Tronchuda); (ii) Portuguese Galega kale (B. oleracea var. acephala De Candolle, Couve Galega); and (iii) other economically less important coles such as Algarve cabbages (B. oleracea var. capitata L., Couve do Algarve or B. oleracea var. sabauda L., Couve Repolho-lombarda do Algarve). The cole accessions were collected from the growers, studied under field conditions during two consecutive years, and characterized using 46 morphological characters from seedling stage to ripe silique. Morphological data were analysed by numerical taxonomy techniques using UPGMA (Unweighted Pair Group Method Using Arithmetic Averages) and by principal component analysis (PCA). Phenograms based on correlation and distance coefficients showed the existence of 8 main groups (A-H). Five of these groups correspond to Tronchuda cabbage landraces: (A) “Couves de Tras-os-Montes”; (B) “Couves do Minho”; (C) “Couves from Central Portugal”; (D) “Couve Portuguesa”; (E) “Couves from Southern inland Portugal”. The three other groups correspond to: (F) cabbages; (G) miscellaneous coles; and (H) Galega kales. Landrace groups are primarily associated with morphological differences among accessions and secondly with accession geographical origin. The interannual character variation did not affect the clustering patterns of the accessions and therefore the stability of landrace classification. PCA was congruent with the landrace groups defined by the phenograms and gave supplementary information on the usefulness of the characters for the definition of the various groups.