http://hdl.handle.net/2067/1159 2013-05-19T15:03:37Z 2013-05-19T15:03:37Z Speranza, Stefano Caccia, Riccardo Fonzo, Valentina Pucci, Claudio Soressi, Gian Piero http://hdl.handle.net/2067/2323 2012-08-30T23:05:42Z 2000-12-31T23:00:00Z

Title: Tomato plants transgenic for an Arabidopsis thaliana cystein proteinase inhibitor (Atcys) impair the life cycle of Helicoverpa armigera (Hüb.) Authors: Speranza, Stefano; Caccia, Riccardo; Fonzo, Valentina; Pucci, Claudio; Soressi, Gian Piero Abstract: Atcys tomato (Lycopersicon esculentum Mill.) transgenic plants, expressing a cystein proteinase inhibition level double than the untransformed control (Speranza et al. in press), were used for in vivo assays with H. armigera larvae. This insect pest, extremely polyphagous, has recently caused severe damages to the outdoor tomato crop due to the dropping of infested young fruits and to fruit rotting because of the larval galleries. Plants of the cv. Riogrande (RIG) and of the corresponding Atcys homozygous transgenic line (BG-106) were grown in greenhouse and leaves utilized for feeding H. armigera larvae, reared for four days with artificial diet. The recorded data were larval weight (every two days until the cocoon stage), cocoon sex and morphometric traits, number of adults emerged from the cocoon, number of layed and hatched eggs. The mean weight was generally higher when larvae were fed with BG-106 leaves. By subdividing in three periods the larval life, no difference in mortality was observed between larvae reared with control (RIG) and with BG-106 leaves. The percentage of adults emerged from the cocoon was 81% and 76% for the control and BG-106 respectively. The sex ratio (males/females) was in favour of the female sex both for the RIG (0.87) and BG-106 (0.73) cocoons. On average, the fertility (number of layed eggs) of the BG-106 fed females was 33% lower than the control. By considering the percentage of hatched eggs (emerged larvae), the value obtained was 6.8% for BG-106 against 11% for RIG. According to these data, in Atcys transgenic tomato (BG-106), a level of cystein proteinase inhibition double than the untransformed control, is sufficient to negatively influence the H. armigera biological cycle, even if the weight of the larvae fed with the BG-106 leaves is on average higher than the control (RIG). The last datum is in agreement with similar experiments reported in literature where the effect of proteinase inhibitors is tested in different host-pest systems.

2000-12-31T23:00:00Z Caccia, Riccardo Schettino, Maria Farisei, Francesca Savazzini, Federica Poerio, Elia Speranza, Stefano Pucci, Claudio Soressi, Gian Piero http://hdl.handle.net/2067/2322 2012-08-30T23:05:43Z 1998-12-31T23:00:00Z

Title: BBI and Kunitz serin-protease inhibitor action in tomato transgenic plants towards Helicoverpa armigera larvae Authors: Caccia, Riccardo; Schettino, Maria; Farisei, Francesca; Savazzini, Federica; Poerio, Elia; Speranza, Stefano; Pucci, Claudio; Soressi, Gian Piero Abstract: Several crop varieties with agronomically-compatible levels of resistance to insects have been generated by Bt gene transfer. Plant proteinaceous proteinase inhibitors have potential for increasing resistance of crop to insect pests. Proteolytic activities in the larval guts of Helicoverpa armigera (a major pest of solanaceae) have been investigated and proved to be largely due to extracellular serine proteinases (trypsin- and chymotrypsin-like activities) with alkaline pH optimum. With the aim of obtaining tomato transgenic plants resistant to H. armigera larvae, we transformed - the cultivar Riogrande with the gene KTI3 (coding for a soybean Kunitz Inhibitor) and the cultivar UC-82 with the gene Pi-IV (coding for a soybean Bowman-Birk Inhibitor). Leaf extracts of transgenic plants contained significant levels of inhibitory activities towards both bovine pancreatic trypsin and insect trypsin-like enzyme, on average 187- and 5-fold higher-than controls, respectively. The trypsin inhibiting activity was found stable atdifferent plant phenological phases in fruits and leaves; this activity resulted stable for 24h in detached leaf discs used to feed insects. Both inhibiting activities were able to contrast development of H. armigera larvae, by interferring with midgut trypsin-like activity that was found higher in III-IV ages than other ages.

1998-12-31T23:00:00Z Paparatti, Bruno Speranza, Stefano http://hdl.handle.net/2067/2321 2012-08-27T23:05:48Z 1998-12-31T23:00:00Z

Title: I principali fitofagi del castagno Authors: Paparatti, Bruno; Speranza, Stefano Abstract: Vengono presentati i principali fitofagi del castagno in Italia centrale. Per ogni fitofago riportato vengono proposti dei sistemi di controllo.

1998-12-31T23:00:00Z Paparatti, Bruno Speranza, Stefano http://hdl.handle.net/2067/2320 2012-08-27T23:05:28Z 2002-12-31T23:00:00Z

Title: Controllo agronomico del balanino delle castagne Authors: Paparatti, Bruno; Speranza, Stefano Abstract: Il lavoro riporta logiche di controllo agronomico dei balanini delle castagne in Italia. Le infestazione di questi insetti possono interessare anche il 60% della produzione.

2002-12-31T23:00:00Z