Relationships between four measures of genetic distance and breeding behavior in spring wheat

Abstract

ABSTRACT. We estimated the genetic distances among 10 spring wheat genotypes based on pedigree data, morphological traits and AFLP markers, used individually and combined with morphological traits, to find the best predictors of general-and specific-combining abilities among parental genotypes. Ten wheat parents were crossed in a diallel form, disregarding reciprocal hybrids, totaling 45 combinations. The F 1 hybrids, F 2 populations and parents were evaluated in the field in 2007. The experimental plots consisted of 20 plants for F 1 hybrids and 40 plants for parental and F 2 populations. All methods (pedigree data, AFLP markers and morphological traits, used individually and combined) were found to be useful for the assessment of genetic diversity. The significant coefficient correlations ranged from low (0.45) to moderate (0.67) between the distance measures and hybrid performance. There was significant agreement between the distance measures based on AFLP markers vs morphological traits + AFLP markers (r = 0.47) and between pedigree data vs morphological traits 2391+ AFLP markers (r = 0.43). The pedigree distance was positively associated with traits 100-kernel weight and grain yield per plant in F 1 (correlations of 0.67 and 0.62, respectively) and F 2 (correlations of 0.62 and 0.59, respectively) generations. These correlation values indicate that the genetic distance, based on pedigree data, could replace diallel crosses for the selection of parents with higher combining ability and with moderate reliability.

Selection criteria for high-yielding and early-flowering bread wheat hybrids under heat stress

“…Nevertheless, the association between GD and heterosis remains unclear. Significant relationship between GD and heterosis has been shown for water absorption, dough development, grain weight, and grain-yield traits in wheat [3,10,64]. Our results showed that GD was positively and significantly correlated with heterosis effects for GFD, HI, GY, and GFR, indicating the potential of molecular markers for predicting hybrid performance [62].…”

“…The results of correlation analysis between the GD of parents and SCA effects was consistent with those obtained using heterosis (Table 6). Many researchers have reported significant correlations between GD and yield-related traits and the suitability of molecular distance for predicting single-cross performance [3,10,62,64]. According to Benin et al [64], the lack of correlation can come back to additive gene effects for the traits and/or parents involved in the crosses have the same genes, making the expression of SCA unexpected and at random.…”

“…Many researchers have reported significant correlations between GD and yield-related traits and the suitability of molecular distance for predicting single-cross performance [3,10,62,64]. According to Benin et al [64], the lack of correlation can come back to additive gene effects for the traits and/or parents involved in the crosses have the same genes, making the expression of SCA unexpected and at random. However, if markers correlated with specific traits are chosen, their use in assessing genetic diversity and hence hybrid performance can be more competent [75].…”

Identification of duplicates in cassava germplasm banks based on single-nucleotide polymorphisms (SNPs)

“…The ability to identify breeding populations with high agronomic performance is an objective in the development of new varieties of cassava (Oliveira et al, 2015). In addition, according to Semagn et al (2012), it is recognized that close groups of diversity tend to increase redundancy in several breeding programs; therefore, their use in crossbreeding may result in a waste of time and resources since crossbreeding low genetic complementarity parents can produce progenies of low performance (Dias et al, 2003;Benin et al, 2012). On the other hand, crosses of genetically divergent parents may result in high phenotypic variation in progenies.…”

Relationship between progeny growth performance and molecular marker-based genetic distances in Eucommia ulmoides parental genotypes

“…Moreover, with respect to forest trees, delays before assessing individual performances are long, and a strategy for predicting heterosis before making the crosses and thereby reducing the number of combinations to be tested would be particularly desirable. Many observations and studies consistently provided evidence that there is a correlation between the genetic distance of parents and progeny performance or heterosis for most crops (Zhang et al, 1996(Zhang et al, , 2007Hale et al, 2007;Devi and Singh, 2011;Benin et al, 2012) and several forest trees (Vaillancourt et al, 1995;Kopp et al, 2002;Dias et al, 2003). In these studies, genetic distances were estimated by molecular markers involving restriction fragment length polymorphism, random amplified polymorphic DNA, simple sequence repeat, amplified fragment length polymorphism (AFLP), sequence-related amplified polymorphism (SRAP), and inter-simple sequence repeat (ISSR).…”