Items from Italy.

ITEMS FROM ITALY

 

ISTITUTO SPERIMENTALE PER LA CEREALICOLTURA
Via Cassia 176, 00191 Roma, Italy.

 

Reactions of Italian durum wheat cultivars to a mixed SBWMV and WSSMV infection. [p. 87-88]

V. Vallega, C. Rubies-Autonell, and C. Ratti.

WSBMV is widespread in Italy, whereas WSSMV has been reported only on a relatively few farms, often in a mixed infection with WSBMV. During the 1998­99 season, 43 durum wheats were grown near Rome in a field severely infested with both WSBMV and WSSMV and evaluated for resistance to both viruses. The experiment was in collaboration with Drs. C. Rubies-Autonell and C. Ratti (College of Agriculture, University of Bologna). The response of each wheat to the complex syndrome was determined on the basis of their agronomic performance and on field symptom scores and ELISA readings. The results showed that nearly half of the cultivars tested were susceptible to both WSBMV and WSSMV and that 13 were susceptible to either WSBMV or WSSMV. Eight cultivars (Claudio, Colorado, Dupri, Gianni, Iride, Nefer, San Carlo, and Svevo) appeared to be resistant or moderately resistant to both WSBMV and WSSMV. Of these eight cultivars, the most resistant appeared to be Dupri, a newly released wheat that showed mild symptoms, very low ELISA values, and the second highest grain yields. Correlations between ELISA values, field symptom scores, and each of the agronomic characters considered were moderately high. Regression analyses showed that the four cultivars with the most severe symptoms suffered a mean grain yield loss of about 60 %. These wheats headed about 5 days later than usual and suffered a 10 % kernel-weight reduction. Cultivars with relatively mild symptoms also were severely damaged by the complex syndrome in terms of both grain yield and mean kernel weight.

 

 

EXPERIMENTAL INSTITUTE FOR CEREAL RESEARCH
via Mulino, 3 - 26866 S. Angelo Lodigiano (LO), Italy.

 

Allelic variability at the waxy loci in Italian wheat germ plasm. [p. 88]

G. Boggini, M. Cattaneo, and P. Vaccino.

Waxy wheats, characterized by a reduction or an absence of amylose in the starch, may find a use in the production of modified food starch, and their flour may be used to extend the shelf life of baked products. The primary enzyme responsible for the synthesis of amylose in amyloplast, granule-bound starch synthase (GBSS), is present in bread wheat in three isoforms encoded by the structural genes Wx-A1, Wx-B1, and Wx-D1. We analyzed 288 cultivars of bread wheat, 139 cultivars of durum wheat, and about 200 accessions from other Triticum species in order to find genetic variability for the waxy trait. Electrophoretic separation of GBSS allowed the identification of 63 bread wheats deficient in the Wx-B1, one in the Wx-A1, and one in the Wx-D1 protein isoforms, and a T. dicoccum lacking the Wx-A1 isoform. Work is in progress to evaluate the starch properties of the wheat mutants and select waxy genotypes by crossing the most interesting mutants.

 

Hybrid wheat development. [p. 88]

M. Perenzin, M. Corbellini, and G. Boggini.

Several European countries introduced into practical agriculture in the last few years F1 hybrids produced by means of chemical hybridizing-agents. In Italy, although a positive trend was observed in the yield potential of the hybrids produced in the last 15 years, the level of standard heterosis did not increase, therefore showing the need to develop specific breeding strategies for the selection of parents. A breeding program based on recurrent selection and aimed at selecting parental lines with high levels of general and specific combining ability was started in 1995. A total of 142 lines were evaluated for agronomic and quality performance according to a test cross design and also were fingerprinted with AFLP markers. The application of a nonconventional breeding strategy to identify superior parents is in progress.

 

Breeding for resistance to powdery mildew. [p. 88]

A. Brandolini and G. Boggini.

A breeding program based on backcrossing and aimed at the introduction of powdery mildew resistance gene Pm13 in bread wheat cultivars started in 1998. Wheat lines with the Ae. longissima introgression, developed by C. Ceoloni at the Viterbo University, were crossed with 18 Italian cultivars. The availability of a RAPD marker linked to Pm13 gene allowed for MAS of the progenies in lieu of artificial inoculations. Backcrosses (BC4) and line evaluations are in progress.

 

Genetic analysis of einkorn wheat quality traits. [p. 89]

A. Brandolini, P. Vaccino, S. Empilli, M. Corbellini, and G. Boggini.

Einkorn wheat is one of the crops that founded Neolithic agriculture in the Fertile Crescent. We found genotypes producing flours with good technological properties and bread volumes in the range of actual bread wheats in a collection of 1,500 accessions. Considering that einkorn also is characterized by other traits of good quality (high protein, dietary fiber, and carotene content) and good resistances to many biotic and abiotic stresses, we initiated studies on their genetic basis. Lines derived by three- and four-way crosses among T. monococcum genotypes with different characteristics (earliness, gluten quality, free threshability, short straw, and large kernel) were made, and the resulting progenies are being grown in replicated plots trials. Two crosses are being utilized to produce a molecular map by means of RFLP and AFLP markers and for the identification of QTL for quality and agronomic traits.

 

Publications.

  • Annicchiarico P, Pecetti L, Boggini G, and Doust MA. 2000. Repeatability of large-scale germplasm evaluation results in durum wheat. Crop Sci 40(6):1810-1814.
  • Boggini G, D'Egidio MG, De Noni I, Pellegrino L, Racinelli F, and Pagani MA. 1999. Effect of durum wheat genotype and environment on the heat-damage of dried pasta. J Genet Breed 53:337-347.
  • Brandolini A, Landi P, Monfredini G, and Tano F. 2000. Variation among Andean races of maize for cold tolerance during heterotrophic and early autotrophic growth. Euphytica 111:33-41.
  • Corbellini M, Empilli S, Vaccino P, Brandolini A, Borghi B, Heun M, and Salamini F. 1999. Einkorn characterization for bread and cookie production in relation to protein subunit composition. Cereal Chem 76(5)727-733.
  • Corbellini M, Canevara MG, Empilli S, and Boccardi F. 2000. Near infrared reflectance spectroscopy for quality evaluation of Triticum monococcum. In: Proc 9th Internat Conf Near Infrared Spectroscopy (Davies AMC and Giangiacomo R eds). pp. 683-687.
  • Palumbo M, Spina A, and Boggini G. 2000. Agronomic and bread-making characteristics of durum wheat genotypes deriving from interspecific hybridisation with bread wheat. In: Durum Wheat Improvement in the Mediterranean Region New Challenges (Royo C, Nachit MM, Di Fonzo N, and Araus JL eds). Options Méditerranéennes Serie 40:515-518.