Repeatability of full-sib sugarcane families across harvests and the efficiency of early selection

Abstract

This study was designed to estimate the repeatability coefficient of traits of the plant-cane and first rattoon in a large number of full-sib sugarcane families and to select the superior families based on their predicted genotypic values. The population used in this study consisted of 190 families, and crossing was performed at the Federal University of Alagoas, in Murici, Alagoas, Brazil, in 2007. Five experiments, each with 22 families, took place at the Centro de Pesquisa e Melhoramento da Cana-de-Açúcar (CECA), in Oratórios, Minas Gerais, while four experiments, each with 20 families, took place at the Volta Grande mill (VGM), in Conceição das Alagoas, Minas Gerais. Each experiment took the form of a randomized complete block design with six replications. The following traits were determined from the plant-cane and first rattoon: percentage of soluble solids w/w in the juice (Brix), tons of stalks per hectare (TSH) and tons of brix per hectare (TBH). Statistical analyses were performed using the mixed model methodology. Variance components were estimated by restricted maximum likelihood (REML) and the genotypic values of families were predicted by best linear unbiased prediction (BLUP). The moderately high estimates of repeatability for TSH and TBH and the high rates of coincidences of the families selected in both plant-cane and first rattoon indicate that selection of families using repeated measures across the first two harvests combined with individual clone selection at the rattoon stage may be efficient in sugarcane breeding programs, increasing the efficiency of obtaining new cultivars.

Selection of sugar cane families by using BLUP and multi-diverse analyses for planting in the Brazilian savannah

“…These values corroborate the study of Leite et al (2009), who obtained heritage values of 0.88 for TBH and 0.66 for BRIX. In contrast, Pedroso et al (2011) obtained 0.48 and 0.30 for TBH and BRIX, respectively. The observed range in heritability obtained by these studies might have been caused by several factors.…”

“…Some authors have already showed that the use of family selection contributes to parental selection, in addition to mating, which aim to obtain improved populations (Kimbeng and Cox, 2003;Shanthi et al, 2008). The strategy of family selection has been previously used in some sugar cane improvement projects in Brazil (Leite et al, 2009;Pedroso et al, 2011).…”

Breeding full-sib families of sugar cane using selection index

“…Selection based on the average of families is more effi cient than that based on individual plants, when traits of low heritability are considered. PEDROZO et al (2011) reported that heritability estimates based on averages of families were generally higher, compared to its estimates in individual plants for the six traits studied. Since selection for sugar productivity is ineffi cient in the fi rst clonal generations, breeding programs have conducted parallel selection studies based on the selection of superior families (BARBOSA et al, 2004;BARBOSA et al, 2005).…”

Software Selegen-REML/BLUP: a useful tool for plant breeding

“…The software Selegen-REML/BLUP has been used internationally (Colombari et al 2013, Oliveira et al 2012, Pedrozo et al 2011, Rosado et al 2010, Dunlop et al 2005, and is a very useful tool for plant breeding. …”