Very little information is available on neck blast resistance in Italian rice varieties under field conditions. In order to provide these data, 105 cultivars were tested under very favourable conditions for the disease development; the cultivars' response to a single treatment of tricyclazole was also evaluated. Among tested varieties, 15 % showed resistance to the disease, 17 % moderate resistance, 30 % moderate susceptibility and 38 % susceptibility. Generally, recently developed cultivars were more tolerant to neck blast, compared to the oldest ones. Furthermore, cultivars with Long A grain shape are the most susceptible to neck blast, followed by medium grain type, round grain and Long B grain shape. A single spray of tricyclazole (450 a.i. g/ha) was effective in reducing disease incidence (55 % average reduction). It was also observed that there was a reduction in severity of symptoms. The majority of rice Italian cultivars are susceptible to neck blast disease. This study underlines the importance of field tests as useful tool for researchers, breeders and growers, combining scientific value with impact in application, giving valuable information to improve disease control.

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Efficient germplasm exploitation in crop breeding requires comprehensive knowledge of the available genetic diversity. Linking molecular data to phenotypic expression is fundamental for the profitable utilisation of genetic resources. Italian rice germplasm is an invaluable source of genes, being characterised by marked heterogeneity. A phenotypic characterisation is presented in this paper, with a focus on the evolutionary trends, and on the comparison with available molecular studies. A panel of 351 Italian rice varieties was analysed using seven key morphological traits, employing univariate and multivariate analyses. Considerable variability was found, with clear morphological trends towards reduced plant height, earliness, and spindle-shaped caryopses. Previous findings indicating that genetic diversity was maintained throughout time could not be confirmed, as small phenotypic variability was found in the most recent rice varieties. Consistency with phylogenetic data from previous studies was partial: one phylogenetic subgroup was phenotypically well distinct, while the others had overlapping characteristics and encompassed a wide range of phenotypic variation. Our study provides a quantitative ready-to-use set of information to support new breeding programs, as well as the basis to develop variety-specific calibrations of eco-physiological models, to identify promising traits in light of climate change conditions and alternative management scenarios.

Plant breeding is one of the key strategies for further enhancement of crop yields; however, effective breeding strategies require phenotypic characterisation of the available germplasm. This study sought to characterise the phenotypic expression of fourteen crop traits related to phenology, plant architecture, and yield in a panel of 40 cultivars selected to represent the phenotypic variability present in Italian rice germplasm during a two-season field experiment. The observed range of phenotypic variation was high for many traits (coefficients of variation ranging from 5.9% to 45.4%) including yield (mean: 6.47 t ha-1 ; CV: 15.4%; min: 2.19 t ha-1 ; max: 8.95 t ha-1), and multiple strong associations emerged in all the analysed traits. Cluster analysis extracted three groups of genotypes characterised by alternative yield strategies, i.e. "high-tillering", "early maturing", and "increased source-sink". Our findings highlight that rice yield decrease when one strategy is overemphasised. In contrast, the highest-yielding genotypes have a balanced ratio between sink and source organs, along with a proportional duration of vegetative and reproductive phases. This study depicts the phenotypic variability in Italian rice cultivars and proposes a novel classification based on yield-related traits which could be of use in multiple rice breeding applications.