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GrainGenes Reference Report: JID-96-227

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Reference	JID-96-227
Title	Response of durum wheat cultivars to Algerian environments - IV. Implications on a national breeding strategy
Journal	Journal of Agriculture and Environment for International Development
Year	2002
Volume	96
Pages	227-259
Author	Annicchiarico P [ Show all 6 ]
Abstract	This study, based on grain yield responses of 24 durum wheat cultivars across 2 years and 17 Algerian locations, aimed at supporting the strategy of Algerian durum wheat breeding by: (i) focusing on adaptive responses of 2 recent Algerian varieties and their parent material, (ii) identifying candidate subregions for specific breeding, and scaling up site classification results by means of Geographic Information System (GIS) tools, and (iii) comparing wide- vs. specific-adaptation strategies in terms of yield gains predicted over the region. An empirical comparison of 7 techniques for site classification was also provided. The Algerian cultivars, which derived from crosses between landrace and improved variety germplasm, showed responses typical of improved material, with modest adaptation to severely cold- and drought-stressed sites. Classification of sites into 2 subregions was performed by pattern analysis using within-site standardized data, and by other techniques complementing modelling of adaptative responses for log10-transformed data, to reduce the heterogeneity of genotypic variance among locations. Site classification results provided by pattern analysis and by AMMI (Additive Main effects and Multiplicative Interaction)+ cluster analysis (adopting Ward's clustering method, and a squared Euclidean distance as the dissimilarity measure) maximized the predicted yield gain from a specific-adaptation strategy and showed a fairly low consistency of genotype responses between subregions. Site classification was up-scaled by a discriminant analysis-based procedure that held site altitude and long-term winter mean temperature (across January and February) for the former and latter technique, respectively, in the discriminant function. The 2 GIS-based definitions of subregions were very similar and revealed a low-elevation, milder subregion (including about 65% of the potential durum wheat cropping area) and a high-elevation, cold-prone subregion. The advantage of a specific-adaptation strategy relative to wide adaptation ranged between 11% and 13% as estimated by predicted yield gains over the cropping region, which may increase if it also implied, for each subregion, a distinct genetic base and/or the allocation of different material based on specific adaptive traits. Higher temporal yield stability may be considered as a breeding target only for the less favourable subregion
Keyword	adaptation [ Show all 18 ]

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