Hybrid necrosis as a barrier to gene transfer in hexaploid winter wheat × triticale crosses

An interspecific wheat × triticale hybridization program was initiated with the scope of widening and improving the winter wheat gene pool. However, progress was hampered by severe necrosis that caused the death of F1 hybrids from crosses between the most winterhardy wheat and triticale cultivars. This paper describes hybrid necrosis as the main barrier to gene transfer between winter wheat cultivars Borden, Augusta and Ruby, and hexaploid winter triticales OAC Wintri and K9-6. Crosses with tester lines revealed that the three winter wheats were carriers of the necrotic Ne2 allele. High temperature (30 °C) treatment until heading stage permitted to only partially circumvent the problem. A study of cross direction effects at the backcross level showed that the conventional method (F1 × wheat) was more efficient for plant recovery, but plants produced by the alternative backcross system (wheat × F1) were more self-fertile. Within the most winterhardy germplasm, hybrid necrosis is a major problem for transferring genes between winter wheat and triticale. The use of non-necrotic winter wheat lines such as MC11N, a local winter wheat selection, may have a special value as a bridge to circumvent the necrosis problem. Key words: Hybrid necrosis, Ne genes, wheat × triticale hybrids, cross direction </jats:p

Effectiveness of the Field Selection Parameters on Potato Yield in Atlantic Canada

Published online: 12 August 2016Cultivated potatoes (Solanum tuberosum L.) are the 4th most important crop feeding the world. Therefore, yield is a crucial trait for potato breeding and germplasm enhancement. The analysis of phenotype data of potato plants enables the extraction of crucial phenotypic characters for potato yield breeding. Using data collected from 179 advanced breeding clones that were planted in evaluation trials over three years at the Benton Ridge breeding substation in Atlantic Canada, we deciphered the dynamic properties of trait expression over the growth period based on nine parameters used in Agriculture and Agri-Food Canada’s potato breeding program. The analysis of breeding data provided valuable information to understand the factors that contribute to the phenotypic performance of potato and potato tuber yield. Linear mixed model fit by maximum likelihood and principal component analysis (PCA) were employed as complementary analysis tools to analyze these characters to try to uncover the relationship of complex agronomic traits. Our results showed that the majority of the selection parameters effectively contributed to the improvement of potato tuber yield. The first five principal components (PCs) accounted for 74.9% of the phenotypic variation observed from 2012 to 2014. The maturity, early vigor, eye depth, and top vigor are the most important phenotypic parameters affecting potato tuber yield selection. Based on the results, these selection parameters are yet highly independent variables which also displayed some degree of interrelationship

Development of an effective protoplast fusion system for production of new potatoes with disease and insect resistance using Mexican wild potato species as gene pools

Somatic hybridization through protoplast fusion is an important alternative approach for overcoming sexual incompatibility between diploid Solanum species and cultivated potatoes. However, compared with other potato species, methods for protoplast isolation and plant generation for several Mexican wild diploid potato species are not well established. In this study, a systematic procedure was designed for the isolation of a large number of high-quality protoplasts from various Mexican wild species that carry high levels of disease (late blight) and insect [Colorado potato beetle (CPB)] resistance. Using this procedure, an effective potato protoplast fusion system was developed to produce new somatic hybrids between two Mexican, one Argentina wild species, and cultivated potato clones. Regenerated plants and somatic hybrids were obtained at a high frequency from the protoplasts of the diploid wild species and their fused cells with S. tuberosum. Morphological, cytological and molecular marker analyses demonstrated that somatic hybrids were successfully obtained from the cell fusion of S. tuberosum and the diploid species S. pinnatisectum, S. cardiophyllum, and S. chacoense. Assessment of disease and insect reactions demonstrated that several of the protoplast-derived clones and somatic hybrids showed a higher level of resistance to both late blight and CPB than was found in S. tuberosum, confirming that the protoplast system is a powerful tool in potato breeding programs for the development of disease and insect resistance. This new fusion system provides breeders with opportunities to transfer disease and insect resistance genes from Mexican wild species into cultivated potato. Key words: Somatic hybrid, protoplast, fusion, potato, Solanum, late blight, disease resistance, Colorado potato beetle insect resistance </jats:p

Newdale barley

Newdale is a two-row spring malting barley (Hordeum vulgare L.) cultivar widely adapted to western Canada that has performed particularly well in Manitoba and Saskatchewan. Developed from a cross made in 1991, Newdale was evaluated in the Western Cooperative Two-row Barley Registration Test (1998-1999) and the Collaborative Malting Barley Trials (1999-2000) conducted by the malting and brewing industry before being registered in 2001. Newdale is a significantly higher yielding cultivar with good agronomic traits, moderate disease resistance and good malting quality. Key words: Malting barley, Hordeum vulgare L., cultivar description, yield, disease resistance, malting quality </jats:p

Norman barley

Legge, W. G., Tucker, J. R., Bizimungu, B., Tekauz, A., Noll, J. S., Fetch Jr., T. G., Menzies, J. G., Haber, S., Savard, M. E., Vigier, B. J., Choo, T. M., Martin, R. A., Turkington, T. K., Rossnagel, B. G. and Harvey, B. L. 2011. Norman barley. Can. J. Plant Sci. 91: 1105–1113. Norman is a hulled two-row spring malting barley (Hordeum vulgare L.) cultivar derived from the cultivar CDC Kendall that was widely grown in western Canada and utilized commercially by the malting and brewing industry. Developed in 2000 by in vitro selection using deoxynivalenol mycotoxin in the medium of an anther culture system, Norman was evaluated in the Western Cooperative Two-row Barley Registration Test in 2005 and 2006, and the malting and brewing industry Collaborative Malting Barley Trials in 2006 and 2007, before being registered in 2009. Norman was also evaluated extensively for deoxynivalenol concentration in fusarium head blight (Fusarium graminearum Schwabe) nurseries from 2001 to 2009. Norman accumulates 25 to 30% less deoxynivalenol than its parent cultivar, CDC Kendall, but is similar in all other traits including malting quality. </jats:p