`Italico' and `Mediterraneo': Two Seiridium cardinale Canker-Resistant Cypress Cultivars of Cupressus sempervirens

Abstract

<jats:p>Common cypress (<jats:italic>Cupressus sempervirens</jats:italic> L.) is an integral feature of the landscape of many Mediterranean regions (particularly in Tuscany). Furthermore, common cypress has multiple uses as ornament, timber, windbreaks, recovery of deteriorated soils, protection of slopes and the production of essential oils. During the last three decades, <jats:italic>Seiridum cardinale</jats:italic> canker of cypress has caused severe losses in woods, windbreaks and ornamental plantings in the Mediterranean area, significantly limiting the use and cultivation of this tree.</jats:p> <jats:p>In this paper we describe `Italico' and `Mediterraneo', two <jats:italic>C. sempervirens</jats:italic> varieties which were patented in 2004 for their resistance to cypress canker. Both varieties are particularly suitable for ornamental purposes because of their fastigiated columnar habit and the low production of male flowers and cones. `Italico' and `Mediterraneo' represent the recent result of the breeding programme on cypress, in progress since the 1970s. This program aims at: 1) obtaining a high number of canker-resistant cypress clones and multi-clonal varieties to be used for ornamental plantings and windbreaks and 2) finding mother trees for the production of improved seed for reforestation purposes.</jats:p>

An increase in transmission‐related traits and in phenotypic plasticity is documented during a fungal invasion

“…Finally, we show that quantitative pathogenicity does not increase between source and invasive populations, either because it is not easily evolvable, as it may be determined by multiple loci of both host and pathogen, and/ or because intermediate pathogenicity levels may be ideal to maximize transmission. Nonetheless, native source populations include genotypes that are genetically distinct and display higher pathogenicity than genotypes already introduced: their introduction could lead to increased mortality rates of hosts in the exotic range, even of cultivars currently deemed resistant (Danti et al 2006(Danti et al , 2013b. Based on these results, we conclude that regulations should prevent any further introductions of S. cardinale into the Mediterranean region: this conclusion is also supported by the fact that introductions of a compatible mating type postulated to exist in California (Della Rocca et al 2011) could lead to sexual reproduction among individuals from different provenances, a mechanism known to increase the adaptive potential of invasive species (Facon et al 2008).…”

‘Le Crete 1’ and ‘Le Crete 2’: two newly patentedSeiridium cardinalecanker‐resistant cultivars ofCupressus sempervirens

“…; Danti et al. ). Thus, phenotype is affected by both genotype and environment, and candidates are usually evaluated in different sites to identify the clones with the highest level of resistance for each environment and eventually to select for fairly stable resistant clones (Santini et al.…”

“…First studies evidenced a wide variability of the response to S. cardinale infection among the various species of Cupressus (Raddi 1979;Andreoli and Ponchet 1991), whereas a fair variability was detected within some native and naturalized C. sempervirens populations, with 88% susceptible, around 10% tolerant and less than 2% resistant plants (Raddi 1979;Raddi et al 1990). Reaction of cypress to S. cardinale canker is a quantitative (polygenic) trait, based on the development of a neoperiderm, which gradually ranges from susceptibility (death of trees or stem tops) to resistance, represented by the complete healing of the canker Spanos et al 1999;Danti et al 2006). Thus, phenotype is affected by both genotype and environment, and candidates are usually evaluated in different sites to identify the clones with the highest level of resistance for each environment and eventually to select for fairly stable resistant clones (Santini et al 1997).…”

“…Cypress selection at IPP-CNR has always been addressed towards genotypes having useful traits for users and community. A number of cypress clones and multiclonal varieties have been selected so far with the aim to enlarge as much as possible the genetic variability of the canker-resistant lines, and six C. sempervirens clones were patented between 1986 and 2004 (Raddi and Panconesi 1994;Danti et al 2006). Among these 'Bolgheri', 'Italico' and 'Mediterraneo' have been sold successfully as ornamental, whereas 'Agrimed n. 1' as windbreak and hedge tree.…”

The Epidemic Spread of Seiridium cardinale on Leyland Cypress Severely Limits Its Use in the Mediterranean

“…Since the mid-1970s, efforts were made in Central Italy to con trol the disease by sanitation to reduce the presence of the inocu lum in the environment and also to launch a genetic improvement program aimed at selecting resistant lines of common cypress (10,11). The adopted control measures have led to cypress canker currently approaching a post-epidemic or endemic phase, with a relatively steady prevalence (mean around 22%) registered over the last few years in Tuscan woods and plantations of C. sempervirens (33).…”