Correlation of genetic distance of maize inbred lines (Zea mays L.) with heterosis and SCA for grain yield

Abstract

The results of protein analysis method and diallel analysis (10x10) were correlated in this study. The diallel analysis was used for the estimation of SCA and heterosis of 45 crosses. The protein analysis consisted of the salt soluble protein analysis. Proteins were isolated form embryos of ten maize inbred lines. On the basis of electrophoresis, the genetic distance (GD) between 10 inbred lines was estimated. The estimated genetic distances were in accordance with the data related to the origin of inbreds. The shortest GD was detected among inbreds belonging to the same heterotic group and having a common male component. The longest distance was established between two pairs of inbreds originated from divergent heterotic groups. The classification of inbreds into heterotic groups was confirmed by the cluster and PC analyses based on protein markers. This was also in accordance with the cluster based on data of heterosis and SCA for maize grain yield. Both clusters showed the classification of inbreds into two groups. The first group was formed by inbred lines originated from the BSSS heterotic group, while the other consisted of lines belonging to the Lancaster heterotic group. The deviations were established among inbreds that belonged to neither of these two groups. The results of PCA were in general in accordance with clusters. The concurrence between GD and heterosis, as well as, between GD and SCA for maize grain yield was established by a Spearman's rank correlation coefficient. In such a way, the accuracy of the classification of inbreds into heterotic groups on the basis of GD results was tested. A stronger and highly significant correlation was established between GD and heterosis (rs=0,422**), while it was significant (rs=0,309*) for the GD-SCA relation.

U radu su na osnovu rezultata analize proteinskih markera i dijalelene analize (10x10), utvrđene korelacije između genetičke distance (GD) 10 samooplodnih linija i heterozisa, kao i PKS (posebnih kombinacionih sposobnosti) njihovih hibridnih kombinacija za prinos zrna kukuruza. Najmanja vrednost GD utvrđena je između dve linije poreklom iz istog izvora germplazme, koje su pored toga imale i zajedničkog oca. Maksimalne vrednosti GD utvrđene su između dva para linija, poreklom iz divergentnih heterotičnih grupa, koje se međusobno dobro kombinuju. Grupisanje linija koje je odgovaralo dvema heterotičnim grupama potvrđeno je klaster analizom na osnovu proteinskih markera, a takođe je u saglasnosti sa klasterima na osnovu podataka o heterozisu i PKS za prinos zrna kukuruza. Kod oba klastera linije su bile klasifikovane u dve grupe. I grupu obrazovale su linije BSSS tipa, dok su II grupu činile linije Lancaster tipa germplazme. Utvrđena odstupanja bila su kod linija koje nisu pripadale osnovnim heterotičnim grupama. PC analiza uglavnom je dala iste rezultate. Spearman-ovim koeficijentom korelacije ranga utvrđena saglasnost podataka dobijenih na osnovu GD linija sa heterozisom i PKS za prinos zrna. Ovim je proverena preciznost klasifikovanja samooplodnih linija u odgovarajuće heterotične grupe na osnovu izračunate GD. Jača i visoko značajna korelacija utvrđena je između GD i hetrozisa (rs=0,422**), dok je za odnos GD-PKS iznosila rs=0,309*.