Genetic distance of maize inbreds for prediction of heterosis and combining ability

Abstract

A panel of seven maize inbred lines belonging to Zemun Polje commercial pool were genotypized using SNPs bead chip. 21 hybrids, developed according to the half dialel mating design, were tested in the field together with inbred lines per se. The goal of the study was to determine the genetic distance among seven maize inbred lines and to establish whether there was a significant correlation between the genetic distance among parental inbreds and grain yield, specific combining abilities (SCA) and high-parent (HP) heterosis for the grain yield. The inbred lines ZPL2 and ZPL4 with the genetic distance of 0.487 were the most genetically distant parents, while inbred lines ZPL1 and ZPL2 with the genetic distance of 0.191 were the closest ones. Three subclusters of inbred lines were distinguished in the dendrogram. Inbred lines ZPL5, ZPL6, ZPL3 and ZPL7 were grouped into the first subcluster, while inbred lines ZPL1 and ZPL2, i.e. the inbred line ZPL4 were grouped in the second, i.e. the third subcluster, respectively. The values of the Spearman's rank correlation coefficient between the genetic distance among inbred lines based on the SNP markers, and grain yield, specific combining abilities (SCA) and high- parent (HP) heterosis were positive and statistically significant. The highest correlation coefficient was exhibited between the grain yield and high-parent (HP) heterosis (0.93), and then between the genetic distance and the grain yield (0.92) as well as between the genetic distance and high-parent (HP) heterosis (0.91).

Panel od sedam inbred linija kukuruza koje pripadaju komercijalnom pulu Instituta za kukuruz u Zemun Polju je analiziran pomoću SNP čipa. Hibridi dobijeni po metodu nepotpunog dialela su ispitivani u polju zajedno sa inbred linijama per se. Cilj ovog istraživanja je bio da se utvrdi genetička distanca između inbred linija kukuruza i da se ispita da li postoji značajna korelacija između genetičke distance roditeljskih linija, posebnih kombinacionih sposobnosti (PKS) i heterozisa u odnosu na boljeg roditelja (HPH) za osobinu prinos zrna. Genetički najudaljenije linije su bile ZPL2 i ZPL4 sa genetičkom distancom 0.487, dok su najbliže bile inbred linije ZPL1 i ZPL2 sa genetičkom distancom 0.191, kao i inbred linije ZPL5 i ZPL6 sa genetičkom distancom 0.196. Dendrogram je podelio inbred linije u tri različita subklastera. Prvom subklasteru pripadaju inbred linije ZPL5, ZPL6, ZPL3 i ZPL7, drugom inbred linije ZPL1 i ZPL2 i trećem inbred linija ZPL4. Vrednosti Sperman-ovog koeficijenta korelacije ranga između genetičke distance zasnovane na SNP markerima, prinosa zrna, posebnih kombinacionih sposobnosti (PKS) i heterozisa u odnosu na boljeg roditelja (HPH) su bile pozitivne i statistički značajne. Najviši koeficijent korelacije je bio između prinosa zrna i HPH (0,93), zatim između genetičke distance i prinosa (0.92) i između genetičke distance i HPH (0.91).