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Summary — The breeding of sunflower varieties whose seeds (achenes) can be easily hulled would help to optimise industrial hulling before oil extraction, and thus improve the protein content of sunflower seedmeal. Laboratory hulling tests require samples of about 10 g of seed, and so a search was made for characteristics that would permit indirect selection for improved hullability using smaller numbers of seed. Anatomical characteristics of the pericarps of 12 inbred sunflower lines and 18 hybrids were observed using light microscopy. Significant differences between genotypes in the frequency of parenchyma rays separating sclerenchyma zones, and in the proportion of wide and wedgeshaped sclerenchyma zones were observed. However, the phenotypic correlations between these characteristics and hullability measurements with a laboratory huller were too weak to be usable alone in hullability breeding programmes. Observations of hull structure however will probably serve most usefully to explain certain aspects of variation in hullability.

Nickel (Ni) is an essential element for many organisms; however, it is very toxic at high concentrations and also depending on the species. In macrofungi the mechanisms underlying their Ni tolerance are poorly documented. This study examines, for the first time, the participation of the antioxidative system in Macrolepiota procera exposed to different Ni2+ concentrations and their relation with Ni tolerance. The effect of the pH on Ni tolerance was also evaluated. The fungus was cultivated on solid medium with different NiCl2 concentrations (0.05, 0.2, 0.8 mM) at pH 4, 6, and 8, and fungi growth and Ni uptake were determined. The antioxidative enzymes catalase (CAT) and superoxide dismutase (SOD) and the production of hydrogen peroxide H2O2 were evaluated on fungal submerged cultures within the first hours of Ni2+ exposure. Results showed that M. procera growth decreased when Ni2+ concentrations increased, reaching a maximum growth inhibition (>80%) up to 0.2 mM of NiCl2. Ni uptake increased proportionally to Ni increase in the medium. Both Ni tolerance and Ni accumulation were affected by medium pH. Microscope observations showed differences in the size of spores produced by fungi at different Ni concentrations. Ni exposure induced oxidative stress, as indicated by the production of H2O2, the levels of which seem to be regulated by the antioxidant enzymes SOD and CAT. The time variation pattern of SOD and CAT activities indicated that the former has a greater role in alleviating the stress. The results obtained suggested that tolerance of M. procera to Ni2+ is associated with the ability of this macrofungus to initiate an efficient antioxidant defense system.

In Northeast of Portugal, the macrofungal community associated to chestnut tree (Castanea sativa Mill.) is rich and diversified. Among fungal species, the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare are common in this habitat. The aim of the present work was to assess the effect of the interaction between both fungi on growth, nutritional status, and physiology of C. sativa seedlings. In pot experiments, C. sativa seedlings were inoculated with P. tinctorius and H. fasciculare individually or in combination. Inoculation with P. tinctorius stimulated the plant growth and resulted in increased foliar-N, foliar-P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tinctorius. This result could be related to the inhibition of ectomycorrhizal fungus root colonization as a result of antagonism or to the competition for nutrient sources. If chestnut seedlings have been previously inoculated with P. tinctorius, the subsequent inoculation of H. fasciculare 30 days later did not affect root colonization, and mycorrhization benefits were observed. This work confirms an antagonistic interaction between ectomycorrhizal and saprotrophic fungi with consequences on the ectomycorrhizal host physiology. Although P. tinctorius is effective in promoting growth of host trees by establishing mycorrhizae, in the presence of other fungi, it may not always be able to interact with host roots due to an inability to compete with certain fungi.

ABSTRACT. In Brazil, cultivation of hybrid plants comprise near 40% of the area grown with vegetables. For Capsicum, hybrids of bell and chili peppers have already exceeded 50% and over 25% of all are commercialized seeds. This study aimed to evaluate new pepper hybrids in two environments, Cáceres, MT, and Campos dos Goytacazes, RJ, Brazil. Nine experimental hybrids of C. baccatum var. pendulum were tested and trials were performed in a randomized block design, with three replications and eight plants per plot. In each environment, plants were assessed for canopy diameter, plant height, number of fruit per plant, mean fruit mass per plant, fruit length and diameter, pulp thickness, and content of soluble solids. Seven of the eight traits have differed significantly due to environment variation. Furthermore, genotype and environment interaction was highly significant for number of fruit per plant, mean fruit mass per plant, fruit length, and fruit diameter. Choosing a hybrid to be grown in one of the studied locations must be in accordance with the sought characteristics since there is a complex interaction for some studied traits.

For diagnostic proposes of ink disease, chestnut orchards with symptoms of decline or sudden death of trees were sampled by soil baiting techniques and selective agar media (P 10 VPH). Thirty-six Phytophthora isolates were obtained. One isolate per tree and three or two isolates from the soil of the same plant were considered for molecular identification. Genomic DNA was extracted from all the isolates and from the reference strain P. cinnamomi CECT 2965. The ribosomal regions ITS1, 5.8S and ITS2 were amplified with the universal primer pair ITS6 (Cooke and Duncan, 1997) and ITS4 (White et al., 1990) by PCR. The amplified fragment (900 pb) was digested with restriction enzymes MspI, AluI and TaqI. Two different patterns of fingerprinting were obtained with enzymes TaqI and AluI (type I and II) and three different patterns with MspI (type I, Ia, II). The fingerprinting of each isolate was compared with database of CABI by public web access. Type I and Ia (14 isolates) were assigned to P. cinnamomi and type II (4 isolates) was assigned to P. cambivora. Molecular methods provide a rapid means of Phytophthora species identification associated with ink disease of chestnut and will provide a useful tool for etiological and epidemiological studies of this important disease of chestnut.

Pests and diseases can cause significant loss of olive yield and/or justify control measures with pesticides which are harmful to the environment. Several agroecological variables, such as fertilization, can favour or limit the incidence of pests and diseases. However, in olive, few studies exist on the subject than can assist in the implementation of more sustainable phytosanitary measures. In this study the effect of nitrogen fertilization (0, 20, 40 and 120 kg N ha −1) on the incidence of olive fruit fly (Bactrocera oleae), olive leaf spot (Spilocaea oleaginea) and olive anthracnose (Colletotrichum gloeosporioides) was evaluated in two olive orchards of the cultivars 'Cobrançosa' and 'Madural'. The study took place in 2017 and 2018 in Lombo, NE Portugal. Nitrogen fertilization significantly increased olive yield and nitrogen concentrations in plant tissues and induced a delay in fruit maturity. The incidence of the olive fruit fly was significantly lower in the more fertilized treatments of both cultivars. However, 'Madural' showed itself to be more susceptible than 'Cobrançosa' to olive fruit fly. The effect of nitrogen on the reduction of the incidence of the olive fruit fly was attributed to the delay caused in fruit maturation, which might have desynchronized the attractiveness of the fruits for insects to lay their eggs on their flight curve. In contrast, olive leaf spot and olive anthracnose were not influenced by nitrogen fertilization. As a result, nutrient management in olive groves must balance carefully the requirements of economic rationality with environmental preservation, particularly with regard to the harmful relationship between the use of excessive nitrogen rates and several adverse environmental effects.

O castanheiro europeu (Castanea sativa Mill.) é a árvore central de um sistema agroflorestal extensivo e multifuncional muito característico das montanhas do nordeste de Portugal. A introdução do fungo Cryphonectria parasitica (Murrill) Barr que provoca no castanheiro cancros nos tecidos corticais é desde a sua introdução, em 1989, a principal causa de morte do castanheiro. Não existindo meios de luta eficazes a remoção dos cancros é utilizada para reduzir o inóculo do parasita. O método evidenciou pouca eficácia e a doença está presente em todas as regiões de castanheiro. A Hipovirulência, mediada pela presença do hipovírus CHV1, é um método muito eficaz para o tratamento dos cancros e recuperação dos castanheiros. Foi objetivo deste trabalho avaliar a estrutura da população de C. parasitica para introduzir a Hipovirulência. Em 3 freguesias, onde a doença está presente desde a sua introdução, foi estudada a estrutura populacional do fungo parasita. Numa malha geográfica de 500x500m, 70 pontos de amostragem e 1331 castanheiros foram estudados. A análise geoestatística revelou focos de grande intensidade da doença que variaram de 54,75 a 73,33%. Foram identificados 5 vc types. EU-11 é o grupo dominante com 85,55%, seguido do EU01 (5,34%), EU66 (4,58%) e EU12 (2,90%), considerados novas introduções do parasita. O idiomorfo MAT-1 e MAT-2 estão presentes nas populações estudadas, sendo o MAT-2 dominante. A proporção 1:1 identificada, num dos locais, sugere multiplicação sexuada do fungo. A ainda baixa diversidade vc type na população de C. parasitica aconselha a introdução da hipovirulência como meio de luta preferencial contra o Cancro do Castanheiro em Portugal.