Experimental Study of a Parallel Iterative Solver for Markov Chain Modeling

This paper presents the results of a preliminary experimental investigation of the performance of a stationary iterative method based on a block staircase splitting for solving singular systems of linear equations arising in Markov chain modelling. From the experiments presented, we can deduce that the method is well suited for solving block banded or more generally localized systems in a parallel computing environment. The parallel implementation has been benchmarked using several Markovian models

Detection of viruses infecting Lilium spp. by RT-PCR and Real-Time PCR

In order to enhance the Italian lily bulb production, a breeding program was carried out at CRA-VIV in Pescia (PT – Italy) during the last years. Asiatic hybrids (Lilium × elegans Thunb.), lily cultivars and other native species were involved in the program. The obtained lily lines, which presented interesting traits, were preserved in a collection. After years of vegetative propagation, some of the new selections showed symptoms referable to viral infections. Virus diseases represent some of the most dangerous threats of Lilium, so the application of fast and effective diagnostic techniques for early detection is very important. The aim of the present study, in the frame of a phytosanitary survey of the lily collection, is to investigate the presence and incidence of Cucumber mosaic virus (CMV), Lilium symptomless virus (LSV), Lily mottle virus (LMoV) and two tospoviruses (Impatiens necrotic spot virus, INSV, and Tomato spotted wilt virus, TSWV). Among the 60 samples object of this study, infections by LSV and CMV were frequently observed. Also LMoV was detected in a smaller amount of samples. All of the samples were negative to INSV and TSWV

Lily mottle virus isolate 207/1 coat protein gene, partial cds.

Genbank accession number: JQ65510

Grapevine rupestris stem pitting-associated virus isolate CC17-16, 28 kDa coat protein gene, complete sequence

Genbank accession number: HQ39673

Lily mottle virus isolate 117/3 coat protein gene, partial cds.

Genbank accession number: JQ65510

Grapevine rupestris stem pitting-associated virus isolate SMH22-13, 28 kDa coat protein gene, complete sequence

Genbank accession number: HQ39674

Molecular characterization of biologically divergent strains of GRSPaV

The comparison between results of biological indexing for vein necrosis and molecular analysis permits to elucidate the biological behaviour of GRSPaV molecular variants. Interestingly, expression of vein necrosis symptoms is likely to be restricted to infection with subgroups 2a and 2b. Moreover, clones isolated from vein necrosis affected isolates share more than 90% sequence identity among each other and share less than 84% sequence identity with the latent groups 1 and 3

Phytosanitary survey on pome fruit autochthonous germoplasm in Tuscany

During 2010, a phytosanitary survey was conducted, concerning the occurrence of some of the main virus, viroid and phytoplasma pathogens affecting Malus and Pyrus autochthon germplasm from Tuscany. Samples, consisting of leaves, shoots and phloematic tissues, were collected during spring 2010. In detail, a total number of 97 plants, 73 of which belonging to 29 Malus varieties, and 24 belonging to 13 Pyrus varieties, were tested by RT-PCR and nested PCR for the subsequent pathogens: Candidatus Phytoplasma mali (Ca. P. mali), Candidatus Phytoplasma pyri (Ca. P. pyri), Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV), Apple dimple fruit viroid (ADFVd) e Apple scar skin viroid (ASSVd). Among the eight pathogens investigated, ACLSV and ASPV proved to be the most widespread (both present in 67.0% of tested samples), while ASGV was present in 14.4% of surveyed plants. In detail, ACLSV was detected on 59 Malus and 6 Pyrus plants, while ASPV was found on 54 and 13 accessions of Malus and Pyrus, respectively. Concerning ASGV, infections by this virus have been detected on 13 Malus plants and 1 of Pyrus. The remaining pathogens (ApMV, ADFVd, ASSVd, Ca. P. mali e Ca. P. pyri) were never detected in the surveyed plant