The European seed legislation on conservation varieties: focus, implementation, present and future impact on landrace on farm conservation

After a brief presentation of the European Directives on seed marketing of conservation varieties, data relative to their implementation status are given and discussed in relation to on farm conservation of landraces. Although generally aimed to ensure in situ conservation and the sustainable use of plant genetic resources, the Directives focus on seed production and marketing instead of genetic resource conservation per se. At present, their application has only partially favoured the registration of landraces maintained on farm or preserved in ex situ collections. They can be estimated in thousands in Europe, while only a few landrace with a verified status (51 out of a total of 184 conservation varieties) are presently included in the Common Catalogue. Reasons for this scarce registration are discussed. The European Directives on seed marketing of conservation varieties are a tool to promote on farm conservation of landraces that should be used to a greater extent than at present. Registration of landraces should be strongly and principally promoted by public bodies as a measure to give access to the genetic resources, preserve them on the long term and favour the economic profit of the farmers maintaining them.     

Diversity characterisation of broccoli (Brassica oleracea L. var. italica Plenck) landraces for their on-farm (in situ) safeguard and use in breeding programs

Brassica oleracea L. is an important species that originated in the eastern Mediterranean area. From there, B. oleracea L. subsp. capitata (L.) DC. convar. botrytis (L.) Alef. var. italica Plenck (broccoli) was introduced into Italy where considerable diversification took place. Several landraces of broccoli, which are highly appreciated by local people for their organoleptic traits, are presently cultivated in both large fields and home gardens. In this study, 10 landraces, 4 synthetics derived from landraces and 4 of the most used F1 hybrids were characterised for morpho-physiological and molecular traits with the principal aim of feeding information into the landrace protection schemes being developed in Italy and into breeding programs. The landraces and derived synthetics are well differentiated from each other and from the F1 hybrids for important agronomic and genetic traits. The principal component analysis based on analysis of morpho-physiological traits showed that overall the 2 main components accounted for 67.74 % of the total variation. The neighbour joining tree, based on 23 microsatellite markers, grouped accessions into 2 main clusters. One includes one synthetic variety and 2 F1 hybrids, while the other cluster includes all the other accessions. There were also several sub clusters. Most of the materials examined showed within-accession diversity. The information gathered in this study can be used to protect landraces through the schemes presently being developed in Italy and to register them in the European common catalogue of “conservation varieties”. In situ (on-farm) conservation of landrace diversity is discussed with reference to landrace use.     

Effects of glandular trichomes on the development of Phytophthora infestans infection in potato (S. tuberosum)

S. berthaulltii Hawkes, a wild potato species, possesses two types of glandular trichomes on its leaf surface: types A and B wich confer resistance to insects. Preliminary results indicated that the presence of glandular trichomes also confers resistance to Phytophthora infestans, the causal agent of late blight. In this paper we report the evaluation of trichome characteristics (density and exudate activities) performed on 8 lines of potato, including the control varieties Desirée and Tropicana, 5 hybrid lines derived from intercrosses and backcrosses between S. tuberosum and S. berthaultii and one accession of S. berthaultii. Whole plants of the 8 genotypes were inoculated with a spore suspension of Phytophthora infestans in order to evaluate their resistance to late blight. The resultant disease incidence correlated negatively with type A trichome density and with polyphenol-oxidase (PPO) activity of type A trichome glands. The removal of type B trichomes exudate by leaf dipping in ethanol did not influence the disease development after artificial inoculation of detached leaves. Type B trichome exudate was extracted and the fraction corresponding to Fatty Acids Sucrose Esters (FASE) was recovered after Thin Layer Chromatography and tested on the fungal mycelium in vitro. The FASE exhibited a slight inhibitory effect on mycelium growth. The results of the experiments are discussed, and several hypotheses regarding the possible role of types A and B trichomes are formulated. This revised version was published online in July 2006 with corrections to the Cover Date.     

Characterisation of thirteen cowpea landraces from Umbria (Italy). Strategy for their conservation and promotion

Thirteen landraces of cowpea (Vigna unguiculata (L.) Walp. subsp. unguiculata cv. gr. Unguiculata) have been morphologically and agronomically characterised as part of a plan for safeguarding and protecting plant biodiversity typical of Lake Trasimeno (Umbria, central Italy). Sixty plants per accession were scored for plant vigour, growth habit, flower colour, days to flowering, days to first mature pod, pod length, total number of pods produced, seed colour pattern, 100 seed weight, total seed yield and virus susceptibility. With the exception of vigour and growth habit, all landraces appeared to be well differentiated from one another for all the characters considered. Strategies and problems related to their in situ conservation are discussed.     

Unipodal stance influences radiographic evaluation of foot balance in horses

Lifting the contralateral forelimb (unipodal stance) is often used as a method of restraint in horses. This experimental one group pretest, posttest study was conducted to evaluate the effects of unipodal stance on quantitative radiographic parameters in equine forefeet. Seven nonlame horses were randomly selected. Lateromedial (LM) and dorsopalmar (DP) projections were acquired for both forefeet, squarely placed on blocks, using two X‐ray generators. Radiographs of each foot were acquired first in a bipodal stance, immediately followed by the same radiographic projections obtained in a unipodal stance. The following measurements were recorded for each stance: distal interphalangeal joint (DIPJ) space width on both projections; mediolateral joint balance as the difference between lateral and medial DIPJ space widths on DP projections; extensor process‐to‐middle phalangeal condyle distance; and deep digital flexor tendon angle on LM projections. A matched pairs design and Student's t‐test with a 95% confidence level were used to test for statistical significance. Compared to a bipodal stance, lateral DIPJ space width was significantly reduced on unipodal DP views, whereas mediolateral joint imbalance and to a lesser extent medial DIPJ space width were significantly increased. On unipodal LM views, there was a significant higher degree of DIPJ flexion. These findings suggest that stance should be carefully taken into consideration when measuring radiographic parameters in equine forefeet, especially if assessing foot balance and conformation, as unipodal stance significantly affects the mediolateral balance of the DIPJ on DP radiographs and significantly alters the phalangeal axis on LM radiographs.     

Pulmonary carcinosarcoma in a cat.

A Domestic Shorthaired cat was presented with coughing and severe respiratory distress. Thoracic radiographs revealed a lobar mass and numerous additional cavitated intrapulmonary masses. The cat was euthanized and submitted for necropsy. Histological examination of the large mass revealed 2 distinct neoplastic components consisting of bronchial adenocarcinoma admixed with neoplastic areas composed of highly atypical undifferentiated spindle cells (sarcomatous component). Simultaneous expression of vimentin and cytokeratin by a subpopulation of neoplastic epithelial cells and by rare neoplastic spindle cells was identified. On the basis of histology and immunohistochemical results, a diagnosis of primary pulmonary carcinosarcoma with intrapulmonary epithelial metastases was made. Pulmonary carcinosarcoma is a well-known pathological entity in humans. It is a rare tumor in animals and has not been previously reported in cat.     

A complication probability study for a definitive‐intent,moderately hypofractionated image‐guided intensity‐modulated radiotherapy protocol for anal sac adenocarcinoma in dogs

Previous trials showed the importance of administering radiation therapy (RT) with small doses per fraction in canine pelvic tumours to maintain acceptable toxicity levels. With increased accuracy/precision of RT, namely intensity‐modulated RT (IMRT), this approach might be challenged. Theoretical toxicity calculations for a new definitive‐intent moderately hypofractionated RT protocol for canine anal sac adenocarcinomas (ASAC) were performed, focussing on the risk of toxicity in pelvic organs at risk (OAR). Computed tomography datasets of 18 dogs with stage 3b ASAC were included. Re‐planning with margins for daily image‐guidance/IMRT was performed and a new protocol isoeffective to previously described definitive‐intent protocols was computed. Dose‐volume information were derived from individual plans and used for normal tissue complication probability (NTCP) computations. A 12 × 3.8 Gy protocol was computed for risk estimation. Tumour volumes ranged from 27.9 to 820.4 cm³ (mean 221.3 cm³ ± 188.9). For late rectal toxicity/bleeding ≥grade 2, median risk probability was 2.3% inter quartile range (IQR: 5.9; 95% confidence interval (CI): 1.2, 8.4) (rho = 0.436) and 3.4% (IQR: 0.96; 95%CI: 3.1, 4.0) (rho = 0.565), respectively. Median late toxicities in urinary bladder, kidneys and small bowel were <1%, except in one kidney. Myelopathy/myelonecrosis had a median risk probability of 4.1% (IQR: 23.5; 95%CI: 2.1, 25.2) (rho = 0.366) and 5.6% (IQR: 13.5; 95%CI: 3.1, 14.1) (rho = 0.363), respectively. However, graded risk showed a probability estimate for late spinal cord toxicity of ≥5% in 8/18 patients. The daily‐imaging IMRT 12 × 3.8 Gy protocol for canine ASAC seems tolerable for most cases, even in advanced disease. Theoretical dose computations serve as estimate, but are safe measures before implementing new protocols into clinical use.     

ULTRASONOGRAPHIC FINDINGS IN 13 HORSES WITH LYMPHOMA

Ultrasonography and radiography are commonly used for staging of lymphoma in horses, however there is little published information on imaging characteristics for horses with confirmed disease. The purpose of this retrospective, case series study was to describe ultrasonographic and radiographic findings for a group of horses with a confirmed diagnosis of lymphoma. A total of 13 horses were sampled. Lymphadenopathy (8/13), peritoneal effusion (6/13), splenic (6/13), and hepatic (5/13) lesions were the most frequently identified. The predominant splenic and hepatic ultrasonographic lesions were hypoechoic nodules, organomegaly, and changes in echogenicity. Digestive tract lesions were detected in three horses and these included focal thickening and decreased echogenicity of the small (2/13) and large intestinal (2/13) wall. Thoracic lesions were predominantly pleural effusion (4/13), lymphadenopathy (4/13), and lung parenchymal changes (3/13). Enlarged lymph nodes were detected radiographically (4/13) and/or ultrasonographically (2/13) in the thorax and ultrasonographically in the abdomen (7/13) and in the caudal cervical region (4/13). Findings supported the use of abdominal and thoracic ultrasonography for lymphoma staging in horses. Ultrasound landmarks for localizing cecal and caudal deep cervical lymph nodes were also provided.