The analysis of F3 progeny of four hybridization combinations of corn inbred lines

Kukuruz (Zea Mays L.) je jednogodišnja, kulturna biljka. Zbog razdvojenosti generativnih organa i različitog vremena sazrijevanja muških i ženskih cvjetova na istoj biljci, kukuruz je izrazito stranooplodna biljka. Inbred linije su homozigotne oplemenjivačke linije koje se upotrebljavaju kao roditelji hibridnih kultivara u stranooplodnim vrstama. Takve linije nastaju samooplodnjom, križanjem u srodstvu, povratnim križanjem ili metodom dihaploida. Budući da se homozigotnost najlakše postiže samooplodnjom, upravo se taj postupak najčešće koristi u razvoju inbred linija. Sorte stranooplodnih biljnih vrsta moraju proći postupak samooplodnje kako bi se kod potomstva smanjila heterozigotnost i stvorio određen broj različitih homozigotnih linija. Križanje inbred linija, ovisno o broju roditelja, može biti dvojno, trojno, četverolinijsko ili povratno. Najčešća metoda razvoja novih linija samooplodnog bilja je pedigre metoda, te se ista koristi i kod stranooplodnog bilja. Linije razvijene metodom pedigrea su homozigotne i homogene, ali s novim genskim kombinacijama. Postupak započinje nakon odabira pojedinačnih biljaka koje se križaju da se dobije F1 generacija, koja je genotipski i fenotipski uniformna i u njoj nema izbora. Nakon samooplodnje biljaka F1 generacije obrano sjeme se sije i uzgaja u F2 generaciji, te se postupak ponavlja dok se u jednom redu ne postigne uniformnost biljaka; to je obično u F5 – F7 generaciji. U istraživanju provedenom tijekom 2008. godini prikupljeni su podatci o svojstvima F3 potomstva četiri kombinacije križanja inbred linija. Korištene su deskriptivne statističke metode radi procjene varijabilnosti analiziranih svojstava (duljina klipa, promjer klipa, masa klipa, broj redova na klipu) za potomstva pojedinih kombinacija križanja. Analizom varijabilnosti i korelacije, utvrđene su značajne razlike u odstupanjima i povezanosti pojedinih svojstava, unutar i između kombinacija križanja. Razlike između potomstava, koje su se pokazale značajno signifikantne, različitih kombinacija križanja za sva analizirana svojstva istražene su uz pomoć analize varijance.Corn (Zea Mays L.) is annual, cultivated plant. Due to separation of generative organs, and the different time of maturing of male and female flowers on the same plant, corn is very open pollinated plant. Inbred lines are homozygous breeding lines that are used as parents of hybrid cultivars in open fertilized species. Such lines are formed by self-fertilization, inbreeding, backcrossing or by dihaploid method. Since homozygosity is best achieved by self-fertilization, this procedure is most often used in the development of an inbred line. Varieties of open fertilized plant species must undergo self-fertilization to reduce heterozygosity in the progeny and to create a certain number of different homozygous lines. The crossing of inbred lines, depending on the number of parents, can be single cross, triple cross, double cross or backcross. The most common method of developing new lines of self-fertilizing plants is the pedigree method, and the same is used in the open fertilized plants. The lines developed by the pedigree method are homozygous and homogeneous, but with new gene combinations. The procedure begins after the selection of individual plants for crossing to obtain F1 generation, which is genotypically and phenotypically uniform and there is no choice in it. After self-fertilization of the F1 generation plants, the skimmed seed is sown and grown in the F2 generation, and the procedure is repeated until in one line is achieved plant uniformity; this is usually in the F5 - F7 generation. In a study conducted during 2008, the data of the F3 progeny properties were collected. Descriptive statistical methods were used to estimate the variability of the analyzed properties (piston length, piston diameter, piston mass, number of piston rows) for the progeny of certain hybridization combinations. By analysis of variability and correlation, significant differences were found in the deviations and correlations of certain properties, both within and between the crossing combinations. The differences between the progeny, which proved to be significantly significant, of different combinations of crossings for all analyzed properties were examined with the help of analysis of variance