Brassica cover crops can reduce nematode pests

The possibility of controlling soil-borne pest nematodes by using Brassica species plants as cover crops in the inter-row space of vineyards followed by biomass incorporation and so called biofumigation was investigated in the CORE Organic Cofund project BIOVINE

Exploit biodiversity in viticultural systems to reduce pest damage and pesticide use, and increase ecosystems services provision: the BIOVINE Project

Organic vineyards still rely on large external inputs to control harmful organisms (i.e., pests). The BIOVINE project aims to develop natural solutions based on plant diversity to control pests and reduce pesticide dependence. The capability of plants of increasing the ecosystem resistance to pests and invasive species is a well-known ecosystem service. However, monocultures (including vineyards) do not exploit the potential of plant diversity. BIOVINE aims to develop new viticultural systems based on increased plant diversity within (e.g., cover crops) and/or around (e.g., hedges, vegetation spots, edgings) vineyards by planting selected plant species for the control of arthropods, soil-borne pests (oomycetes, fungi, nematodes), and foliar pathogens. Candidate plants will be identified by a literature review, and the selected ones will be tested in controlled environment or small-scale experiments. The ability of the selected plants to: i) attract or repel target arthropod pests; ii) conserve/promote beneficials; iii) control soil-borne pests by means of biofumigation; iv) carry mycorrhizal fungi to the vine root system to increase plant health (growth and resistance); and v) control foliar pathogens by reducing the inoculum spread from soil, will be investigated. New viticultural systems able to exploit plant diversity will then be designed based on results of BIOVINE activities, following a design-assessment-adjustment cycle, which will then be tested by in-vineyard experiments in France, Italy, Romania, Slovenia, Spain and Switzerland for a 2-year period. Innovative viticultural systems should represent an improved way for pest control in organic viticulture, meanwhile they should positively affect functional biodiversity and ecosystem services. New control strategies may provide financial opportunities to vine growers and lower their reliance on pesticides

Satellitome analyses in nematodes illuminate complex species history and show conserved features in satellite DNAs

Background: Satellite DNAs (satDNAs) are tandemly repeated non-coding DNA sequences that belong to the most abundant and the fastest evolving parts of the eukaryotic genome. A satellitome represents the collection of different satDNAs in a genome. Due to extreme diversity and methodological difficulties to characterize and compare satDNA collection in complex genomes, knowledge on their putative functional constraints and capacity to participate in genome evolution remains rather elusive. SatDNA transcripts have been detected in many species, however comparative studies of satDNA transcriptome between species are extremely rare. Results: We conducted a genome-wide survey and comparative analyses of satellitomes among different closely related Meloidogyne spp. nematodes. The evolutionary trends of satDNAs suggest that each round of proposed polyploidization in the evolutionary history is concomitant with the addition of a new set of satDNAs in the satellitome of any particular Meloidogyne species. Successive incorporation of new sets of satDNAs in the genome along the process of polyploidization supports multiple hybridization events as the main factor responsible for the formation of these species. Through comparative analyses of 83 distinct satDNAs, we found a CENP-B box-like sequence motif conserved among 11 divergent satDNAs (similarity ranges from 36 to 74%). We also found satDNAs that harbor a splice leader (SL) sequence which, in spite of overall divergence, shows conservation across species in two putative functional regions, the 25-nt SL exon and the Sm binding site. Intra- and interspecific comparative expression analyses of the complete satDNA set in the analyzed Meloidogyne species revealed transcription profiles including a subset of 14 actively transcribed satDNAs. Among those, 9 show active transcription in every species where they are found in the genome and throughout developmental stages. Conclusions: Our results demonstrate the feasibility and power of comparative analysis of the non-coding repetitive genome for elucidation of the origin of species with a complex history. Although satDNAs generally evolve extremely quickly, the comparative analyses of 83 satDNAs detected in the analyzed Meloidogyne species revealed conserved sequence features in some satDNAs suggesting sequence evolution under selective pressure. SatDNAs that are actively transcribed in related genomes and throughout nematode development support the view that their expression is not stochastic

Almighty Cover Crops

Fungal pathogens are able to produce inoculum (spores) on plant debris present on the soil surface of vineyards. These spores can then reach plant surfaces and cause severe grapevine infections when environmental conditions are favourable. The capacity of plant diversity to increase the resistance of crops towards pests and invasive species is very well-known. For instance, Brassica spp. have been already investigated for their capacity to effectively suppress soil-borne inoculum of some causal agents of Black-foot disease in grapevines in vineyard soils. It may also have positive effect on the some dagger nematodes. Cover crops also stimulate the development of microbial communities such as arbuscular mycorrhizal fungi. Many management strategies have been developed against these important grapevine pathogens, but the effects of soil cover vegetation or organic mulching against spore dispersal, acting as a barrier, have been scarcely explored. Thus, in the BIOVINE project (www.biovine.eu) specific experiments were planned in order to verify the possibility of using cover crops: i) to control some relevant pathogens producing inoculum (spores) on plant debris present on the soil surface of vineyards; ii) to determine the presence of causal agents of Petri disease of grapevines on the roots of cover crops; iii) to promote mykorrhizal communities associated with grapevine roots; iv) to control arthropod pests (repellent of arthropods or attracting beneficials); v) to investigate Brassica plants effect on the soil-borne pest nematode Xiphinema index

Pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle, 1970 - a new threat to forests in Slovenia?

The present paper deals with the pine wood nematode (Bursaphelenchus xylophilus), which has been placed on the A1 quarantine list in both Europe and Slovenia. The species is extremely offensive, causing fast-paced deterioration in conifers, particularly in those of the Pinus genus and more rarely in those of the Picea, Abies, and Larix genera. The areal, ecological demands, hosts, ecology, and the symptoms of attack on pines of the pine wood nematode are shown. The confirmed vectors (Insecta: Cerambycidae - genus Monochamus) and potential vectors (Insecta: Curculionidae - genus Pissodes andScolytidae) of the pine wood nematode are presented within the framework ofits ecology. The range of potential host plants of the pine wood nematode inSlovenia, climatic conditions, and critical points for the entry and spread of pests are also given. The level of phytosanitary risk presented by the appearance of the pine wood nematode in Slovenia is also evaluated