Prediction of Genotypic Values and Selection Gains in Peanut Lines Derived from a Synthetic Amphidiploid

Abstract

Genotypic values and selection gains were estimated in peanut lines derived from backcrossing with synthetic amphidiploid (A. batizocoi x A. duranensis)4x and a commercial cultivar, based on agronomical traits. Thirteen BC1F3 lines were grown in the field and submitted to 21 d of water suppression. Two earliness and drought tolerant cultivars (BR 1 and Senegal 55 437) were used as controls. Eight agronomic traits were adopted to characterize the lines. The estimates were based on mixed models (REML/BLUP) and Sum of Ranks Selection Index. We found that residual variance was greater than genotypic one, indicating the existence of variability within the families. Most traits showed high accuracy values. Three families showed an increased number of pods/plant, pod length and several seeds/pod. Negative gains were achieved for time for blooming and full pod maturation. As these traits are used as criteria for selection for earliness, these results favour the identification of short-cycle plants and prone to tolerate dry environments.

Selection indexes and economic weights applied to runner-peanut breeding

“…The order of selection, from the first to the last individual, was considered as a category and evaluated in terms of agreement and disagreement, as described in Eq. 14: Similar results have been reported by other authors (Kukanur et al, 2014;Silva et al, 2016;Rathod & Toprope, 2018;Ramos et al, 2020). The study by Kukanur et al (2014) is expressive because those authors estimated the genetic variability, heritability, and genetic gain of 13 traits in a mini core peanut collection, containing 225 fastigiata, vulgaris, hypogaea, peruviana, and aequatoriana accessions.…”

“…A randomized complete block design was adopted, with three repetitions. Standard agronomic practices were applied according to the recommendations described by Ramos et al (2020). After harvesting, the plants were dried under natural conditions for further data collection.…”

Selection of earliness peanut accessions for genetic improvement in a water-restricted environment

“…Early flowering and pod maturation is highly desirable, particularly in water-restricted environments or in crop rotation management involving off-season production (Santos et al, 2013;Ramos et al, 2022). The variability of these traits has often been found in accessions derived from crosses between hypogaea and fastigiate, whose combinations are highly desired by peanut breeders because, in addition to earliness, their progenies also carried an increased yield (Patil et al, 2020;Ramos et al, 2020).…”

“…Harvest began 75 days after emergence (DAE) for earliness accessions and continued until 90 DAE, corresponding with the full pod maturation period described by Santos et al (2013). The following biological traits were recorded for the accessions: Blooming (B), which refers to the beginning of the flowering process, when half of plants have emitted their first flower (Silva et al, 2016;Ramos et al, 2020), main stem height (MSH), number of mature pods per plant (NPP), weight of dry pods per plant (WPP), 100-pod weight (100PW), 100seed weight (100SW), and full pod maturation (FPM), which occurred when 70% of the plant's pods were fully mature (Santos et al, 2013).…”

“…This was considered low, possibly because of the narrow genetic base of the germplasm, considering that they were all collected from the same geographic region in Ceará state, Brazil. Despite difficulties in estimating this trait, it is highly valuable for peanut genetic improvement, and although plant height was negatively correlated with pod yield in upright species, this trend may change when the genetic base of the plant contains an interspecific germoplasm (Santos et al, 2000;Silva et al, 2016;Ramos et al, 2020).…”