Multivariate analysis is based on a statistical principle involving observation and analysis of more than one statistical variable at a time. The variability of 434 accessions of rice (Oryza sativa L.) germplasm from Côte d'Ivoire was evaluated for 10 agro‐morphological traits in upland conditions at M'bé, Côte d'Ivoire (7°5′ N, 5°1′ W) in 2002 using augmented experimental design and analyzed with multivariate methods. The unweighted pair group method of the average linkage (UPGMA) cluster analysis, canonical discriminant analysis, and principal component analysis (PCA) were used to analyze the data obtained. This enabled the assessment of the extent and pattern of variation of the germplasm and identification of the major traits contributing to the diversity. Seven cluster groups were obtained from the 10 agro‐botanical traits using the UPGMA. Canonical discriminant analysis showed the contribution of each trait to the classification of the rice accessions into different cluster groups. The first three principal components explained about 72.24% of the total variation among the 10 characters. The results of canonical discriminant analysis and PCA suggested that traits such as plant height, number of days to heading and maturity, tillering ability, and grain size (weight, length, width, and shape) were the principal discriminatory characteristics. It was concluded that variation exists in the germplasm, which provides opportunities for this collection to be useful for genetic improvement.

Iron (Fe) toxicity is recognized as one of the most widely spread soil constraints for rice production especially in West Africa. Oryza glaberrima the cultivated rice species that originated from West Africa is well-adapted to its growing ecologies. The aim of this study was to identify the promising O. glaberrima accessions tolerant to Fe toxicity from the 2106 accessions held at the AfricaRice gene bank. The screenings were conducted over a four-year period and involved evaluating the entries under Fe-toxic field conditions in West Africa, selecting good yielding accessions and repeating the testing with newly selected lines. Three accessions (TOG 7206, TOG 6218-B and TOG 7250-A) were higher yielding than O. sativa checks under stress but with similar yields under control conditions. These accessions yielded over 300 g/m2 under both Fe toxicity and control conditions. In conclusion, these materials could be used as donors in breeding programs for developing high yielding rice varieties suited to Fe toxicity affected areas in West Africa.

The knowledge of agro-morphological diversity and the distribution pattern of variation among conserved accessions could be an invaluable aid in germplasm management and crop improvement strategies. In this study, the geographical pattern of morphological variation of 880 landrace rice (Oryza sativa (L.)) accessions in Côte d'Ivoire was evaluated for 13 agro-morphological characters. Shannon -weaver diversity index indicated an overall mean of 0.47 ± 0.07 in the collection, with the greatest diversity from derived Savanna and northwest (H 0 = 0.52 and 0.50) while the west-central had the lowest diversity (H 0 = 0.41). Canonical discriminant analysis showed that traits such as panicle length, grain size (weight and length), tillering ability, number of days to heading and maturity were the main discriminatory characteristics. Result of the phenotypic frequency shows that, the landraces from the north and north-western zones were mostly tall, early heading and maturity, compared to those from the west and west-central which were mainly dwarf to medium height, late heading and maturing. This differential distribution of landraces with height, heading and maturity period reflected the distribution pattern of different Oryza sativa landraces in Côte d'Ivoire, which could be useful in germplasm management and breeding programs.

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