Abstract
Genetic parameters in Stylosanthes accessions were estimated through (ANOVA) and REML/BLUP (Restricted Maximum Likelihood /Best Linear Unbiased Prediction), to compare them for the genetic values in order to select superior accessions. Twenty five genotypes were evaluated in two environments in a randomized blocks experimental design with four replications. The genetic parameters were estimated for 12 descriptors by the two methods. Both methods indicating that the accessions presented genetic variability for the descriptors, but, the ANOVA and the REML/BLUP presented divergent values for the unbalanced data and for descriptors with high environmental influence, as it happens with mass descriptors, what, in turn, indicates that the method REML/BLUP leads to a more accurate predictions and allows for the selection of Stylosanthes accessions. It allows the inclusion of characters, even if they present heterogeneity of the residual variance. The indirect selection may be used, because the primary stem length descriptor revealed itself as a good option due to the correlation with the total dry mass. The accessions BGF-016 and BGF-015 are the most promising ones to be taken up by a Stylosanthes plant breeding program for fodder in the Brazilian Semiarid region. Key words: Semiarid, forages, breeding
Highlights
The Stylosanthes genus calls our attention due to its number of species with extraordinary fodder potential with excellent nutritional quality and their easy adaptation to different environmental conditions
Due to the lack of Stylosanthes cultivars developed for the region, it is desirable to establish a plant breeding program for this fodder plant, and the genetic parameters estimation is needed to identify the best strategies to be used in the selection of Stylosanthes individuals which are tolerant to droughts, has high fodder productivity and high nutritional value
When considering the values between the two environments, most of the descriptors presented F maximum below seven (Table 2), except the total dry mass (TDM), dry stalk mass (DSM) and dry leaf mass (DLM) descriptors and the genetic variances (Vg) were higher in comparison to variances of the interaction GxE (Vgxe) and environmental variance (Ve) for almost all descriptors except for side leaflet length (SLL) (Table 3) indicating genetic diversity among the accessions evaluated and demonstrated that the genetic variability among the accessions is partially due to differences among individuals within each accession and, due to characteristics of different species, since the 25 treatments comprised four species (Stylosanthes scabra, Stylosanthes viscosa, Stylosanthes capitata and Stylosanthes humilis)
Summary
The Stylosanthes genus calls our attention due to its number of species with extraordinary fodder potential with excellent nutritional quality and their easy adaptation to different environmental conditions. The procedures normally used for the selection of fodder plants is done by the evaluation of accessions and the selection of the superior ones (Chakraborty, 2004). This selection is more efficient when it is based on the genetic values estimate and in association with variables of economic importance (Assis et al, 2010). Due to the lack of Stylosanthes cultivars developed for the region, it is desirable to establish a plant breeding program for this fodder plant, and the genetic parameters estimation is needed to identify the best strategies to be used in the selection of Stylosanthes individuals which are tolerant to droughts, has high fodder productivity and high nutritional value
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
