Donori poželjnih alela za popravku prinosa zrna f1 hibrida kukuruza

Abstract

U radu su ispitivane linije kukuruza iz različitih ciklusa selekcije dve sintetičke poulacije BSSS i BSCB1. Cilj proučavanja je da se za osobinu prinos zrna proceni koja linija ima najveće relativne vrednosti poželjnih alela za popravku elitnog hibrida. Visoke vrednosti parametra μG* su imale linije B73(C5), B84(C7), B97(C9) i B99(C10) koje su iz kasnijih ciklusa selekcije, dok su niže vrednosti zabeležene kod linija iz početnog ciklusa selekcije. Linije B73 i B84 nisu imale vrednosti razlike μG*-(μD* ili μF*) signifikantno veće od nule. To podrazumeva da se u procesu selekcije može vršiti direktna samooplodnja i selekcija linija iz ukrštanja (ZPL1 x B73) i (ZPL1 x B84), s obzirom da su obe linije donori pokazale srodstvo sa linijom ZPL1. Druge dve linije B97(C9) i B99(C10) su imale pozitivne i značajne vrednosti poželjnih alela za osobinu prinos zrna, koji nisu bili prisutni u elitnom hibridu ZPL1 x ZPL2. Pošto je za obe linije broj recesivnih nepoželjnih alela bio značajno viši to bi u procesu selekcije trebalo povratno ukrstiti F1 generaciju sa linijom roditeljem ZPL2, jer su pokazale srodstvo sa tom linijom. Rangiranje linija donora na osnovu njihove vrednosti procenjene preko četiri korišćena parametra je pokazalo dobro slaganje između parametara μG*, UBND, PTC i NI.

Inbred lines of different cycles of selection of two synthetic BSSS and BSCB1 populations were studied with the aim to evaluate which inbred lines had the highest relative values of favourable alleles for the improvement of the elite hybrid. High values of parameters μG* were estimated in inbreds B73(C5), B84(C7), B97(C9) and B99(C10), which are of the later cycles of selections, while lower values were recorded in inbreds of the initial cycle of selection. The differences of μG*-(μD* or μF*) estimated in inbreds B73 and B84 were not significantly higher from zero. This means that direct self-pollination and the development of inbreds form the crosses (ZPL1 x B73) and (ZPL1 x B84) can be performed in the process of selection, given that both donor inbreds expressed relatedness to the inbred ZPL1. The values of favourable alleles governing grain yield in the other two inbreds B97(C9) and B99(C10) were positive and significant but were not present in the elite hybrid ZPL1 x ZPL2. Since the number of recessive unfavourable alleles was significantly higher for both inbreds, the F1 generation should be back-crossed to the parental inbred in the selection process because they had expressed relatedness to that inbred. The ranking of donor inbreds based on their value estimated by using four parameters showed a good concordance among parameters μG*, UBND, PTC and NI.