Data/hora: 21/09/2024 13:18:56

Biblioteca(s): 	Embrapa Agroenergia.	
Data corrente: 	25/09/2013	
Data da última atualização: 	21/09/2017	
Autoria: 	LAVIOLA, B. G.; OLIVEIRA, A. M. C. e.; BHERING, L. L.; ALVES, A. A.; ROCHA, R. B.; GOMES, B. E. L.; CRUZ, C. D.	
Afiliação: 	BRUNO GALVEAS LAVIOLA, CNPAE; Ana Maria Cruz e Oliveira, Universidade Federal de Viçosa; Leonardo Lopes Bhering, Universidade Federal de Viçosa; ALEXANDRE ALONSO ALVES, CNPAE; RODRIGO BARROS ROCHA, CPAF-RO; Bruno Ermelindo Lopes Gomes, Universidade Federal de Viçosa; Cosme Damião Cruz, Universidade Federal de Viçosa.	
Título: 	Estimates of repeatability coefficients and selection gains in Jatropha indicate that higher cumulative genetic gains can be obtained by relaxing the degree of certainty in predicting the best families.	
Ano de publicação: 	2013	
Fonte/Imprenta: 	Industrial Crops and Products, v. 51, p. 70-76, 2013.	
DOI: 	10.1016/j.indcrop.2013.08.016	
Idioma: 	Inglês	
Conteúdo: 	The aim of this study was to estimate the repeatability coefficient of grain production in Jatropha, theminimum number of measurements needed to reliably predict the genetic value of selected families, andto determine the cumulative genetic gains when considering the selection of the best families based ondifferent number of measurements. The experiment was conducted with 175 accessions (half-siblingsprogenies derived from selected plants in the field) that compose part of a germplasm collection. Suchbank was established in a randomized block design with two blocks. In each block a given accession wasrepresented in a 5 plant/plot scheme (half-siblings). For the analysis, yield data obtained in the yearsof 2009?2012 were considered. The results of this study indicate that the repeatability coefficient ofgrain production in Jatropha is low (0.37), but comparable to other perennial species, and that to achievereliabilities of 70 and 80% in the prediction of breeding values of selected families, 4 and 7 years ofevaluation, respectively, are needed. The results of this study also indicate that the efficiency of earlyselection seems to be small in Jatropha since the coincidence rate of selected genotypes at early age (1 or2 years of evaluation) and genotypes selected in adult age (4 years assessment) is small (17?23%). Finally,taking into account the repeatability coefficients and coefficients of determination, in a hypotheticalperiod of 21 years (which is equivalent to three selection cycles using seven consecutive measurements? R2= 80%), this paper demonstrates that higher cumulative genetic gains can be obtained (159% over108%) by relaxing the degree of certainty in predicting the best families (R2= 65% instead of R2= 80%),since it makes possible to perform a greater number of selection cycles in the same period (7 cyclesinstead of 4).	
Palavras-Chave: 	Crop energy; Jatropha curcas L; Selection.	
Thesaurus Nal: 	biodiesel; plant breeding; quantitative genetics.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Agroenergia (CNPAE)	
Exemplares: 	CNPAE - (2253-1) - UPC - AP - DD -  -  -  - DIS