Comparison of selection methods on 'Pigarro', a Portuguese improved maize population with fasciation expression
2008
Moreira, Pedro M. R Mendes | Pêgo, Silas E. | Vaz Patto, Carlota | Hallauer, Arnel R.
In 1984, Pêgo started, with the CIMMYT support, an on-farm participatory maize breeding (PMB) project at the Portuguese Sousa Valley region (VASO). VASO was intended to answer the needs of small farmers (e.g., yield, bread making quality, ability for polycropping systems). During 20 years of PMB at VASO, mass (MS) and S2 recurrent selection (S2RS) were applied on the maize landrace 'Pigarro'. Morphological (e.g., ear length and fasciation level) and yield evaluations were conducted in Portugal (2-3 locations in 2 years) and in USA (4 locations in one year) using samples from original population, six MS cycles and three S2RS cycles. North American Populations (BS21, BS22, TEPR-EC6) were also included as checks. ANOVA comparisons and regression analyses on the rate of direct response to selection were performed. Response to MS for Iowa showed significant decrease in stalk lodging, while in Portugal ear length significantly decreased, whereas ear diameter, kernel-row number, and fasciation level significantly increased. Selection also significantly increased days-to-silk and anthesis in Portugal. Response to S2RS in Portugal significantly increased days-to-silk, uniformity, and cob/ear weight ratio. These results showed that the methods used by farmer and breeder were not effective for significant yield increase, but the ear size increased significantly for MS and showed a positive tendency for S2RS. Adaptation to farmer needs was maintained for the last cycles of selection.
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