Relationship between Genetic Distance among Parents and Genetic Variance in Populations of Soybean

Abstract

A major goal of soybean [Glycine max (L.) Merr.] breeding is the development and identification of high yielding transgressive segregants. Populations that have greater genetic variations should, on average, have more transgressive segregants than populations with lesser variance. The goal of this research was to study whether the genetic distances between parents of crosses were predictive of which crosses have the greatest genetic variance for yield and other agronomic traits. Genetic variance for seed yield, plant height and maturity date was estimated for three sets of populations in field tests. The first set included eight populations evaluated in 1989 and 1990, the second set included 21 populations evaluated in 1993 and a subset of 13 populations evaluated in 1994, and the third set included 24 populations evaluated in 1994 and a subset of 10 populations evaluated in 1995. The parents of the crosses were evaluated with RFLP markers to estimate RFLP distances (RFD) and for coefficient of parentage (CP) which was subtracted from one to measure genealogical distances (GD). Both GD and RFD were significantly (P < 0.05) correlated with genetic variance for plant height for the first set. There were no significant correlations between either genetic distance estimator and genetic variance for any trait in the second set. In the third set, GD was significantly correlated with maturity and plant height and RFD was significantly correlated with maturity. Genetic variance for yield was adjusted for maturity with covariance analysis. These adjustments reduced the estimates of yield variance and mostly reduced the correlations between yield variance and genetic distance estimates. To further evaluate the predictive ability of GD and RFD, the populations in each set were subdivided in to two groups, one with parents that had the greatest genetic distance and the other with the least distance based on GD or RFD. The average genetic variance for yield of populations in the more distant group was greater than for the less distant group for the first and third set. These differences were significant for the third set in both years for RFD. These results indicate that although genetic distance can not accurately predict genetic variance of individual crosses, it can on average be useful to identify groups of crosses that will produce populations with greater genetic variance

Genetic distance and its association with heterosis in cacao

“…In addition, Arunachalam (1977) has also proven the role of additive x additive epistatic interactions in causing heterosis. Findings on good correlations between the genetic distance of parents (from performance and molecular marker data) and the performance of their hybrids were similar to those reported in cacao and several species (Ghaderi et al, 1984;Shamsuddin, 1985;Cox and Murphy, 1990;Cruz et al, 1994;Ali et al, 1995;Diers et al, 1996;Xiao et al, 1996;Dias and Kageyama, 1997a;Kisha et al, 1997;Lanza et al, 1997;ManjarrezSandoval et al, 1997;Saghai Maroof et al, 1997;Burkhamer et al, 1998). However, there are several reports describing poor correlations (Vaillancourt et al, 1995;Cerna et al, 1997;Helms et al, 1997;Chowdari et al, 1998;Fabrizius et al, 1998;Perenzin et al, 1998;Tenkouano et al, 1998;Bohn et al, 1999;Joyce et al, 1999;Kidwell et al, 1999;Sant et al, 1999).…”

Predicting performance of soybean populations using genetic distances estimated with RAPD markers

“…There was a week correlation (p < 0.05) for plant height in the F 2:9 generation, but the magnitude (0.44) is not useful in predicting the population genetic variances. Other studies carried out on soybeans show that the magnitude of the correlation between GD as estimated by molecular markers and GV depends on the population set and the environmental conditions under which the GV is estimated (Helms et al 1997;Kisha et al, 1997;Manjarrez-Sandoval et al, 1997).…”

“…In theory, genetic distance based on molecular markers has a greater potential for predicting the performance of soybean populations, but the literature shows an apparent dependence on the population set used (Helms et al, 1997;Kisha et al, 1997;Manjarrez-Sandoval et al, 1997). The study reported in the current paper was carried out to verify whether the genetic distance based on RAPD markers is useful for predicting the performance of soybean populations derived from two-way crosses for a set of parents that include adapted and non-adapted inbred lines, in a diallel scheme.…”

Mapping soybean aphid resistance genes in PI 567598B

“…The DNA was extracted with the CTAB (hexadecyltrimethylammonium bromide) method as described by Kisha et al (1997), and the concentration was determined with a ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., Wilmington, DE, USA). Simple sequence repeat (SSR) markers (Song et al 2004) were used to amplify the genomic DNA according to the PCR protocol described by Cregan and Quigley (1997), using a MJ Tetrad TM thermal cycler (MJ Research, Waltham, MA).…”