Selekcija ozime pšenice (Tr. aestivum L.) u ranim generacijama zavisno o kriterijima izbora : doktorska disertacija - Drezner, Georg; Martinić-Jerčić, Zdravko; Kozumplik, Vinko; Kovačević, Josip, agronom, 1950- (Zagreb : G. Drezner, 1996)
Sažetak: U proizvodnom sklopu (500 zrna/m ), u istoj godini istraživanjima su obuhvaćena potomstva ozime pšenice F1 - F4 generacije i roditelji tri kombinacije križanja. Za svaku kombinaciju križanja formirane su F4 populacije, i to: 1) osobnim izborom, izborom na 2) najveći broj klasova/biljci; 3) najnižu vlat; 4) najveći broj zrna/klasu; 5) najveću masu jednog zrna; 6) najveću masu zrna/biljci; 7) najveći žetveni indeks, te 8) kao bulk populacija. Izbor za F4 generaciju proveden je u rijetkom (100 zrna/m ) i gustom (500 zrna/m ) sklopu iz F3 bulk i F3 generacije odabranih biljaka. Za proučavana svojstva: visinu vlati, broj plodnih vlati, broj zrna i masu jednog zrna/klasu, masu zrna/biljci i žetveni indeks, procijenjeni su varijabilnost, heritabilnost, stupanj dominacije, genetska i ostvarena dobit od selekcije.
Također, vrednovani su i pojedini selekcijski kriteriji u svakoj kombinaciji križanja. Za masu zrna i broj plodnih vlati/biljci utvrđen je najveći, a za visinu vlati najmanji varijacijski koeficijent. S obzirom na stupanj dominacije procjene su od djelomične dominacije do superdominacije za višu vlat i veću masu jednog zrna, dok su za ostala istraživana svojstva procjene od dominacije i superdominacije u jednom do dominacije i superdominacije u drugom smjeru. Najveći je heritabilitet utvrđen za visinu vlati, dok je za ostala svojstva znatno varirao. Procjene genetske dobiti od selekcije vrlo su velike za visinu vlati, velike za masu zrna/biljci, a osrednje za broj zrna/klasu. Izravna selekcija na pojedino svojstvo ima najviše učinka na sniženje vlati i povećanje mase jednog zrna, a u velikoj mjeri i na povećanje mase zrna/biljci.
Za najveću masu zrna/biljci najbolji selekcijski kriteriji su izravna selekcija na ovo svojstvo, osobni izbor oplemenjivača i izbor na najveću masu jednog zrna. Ukupno, za sva proučavana svojstva najbolji pojedinačni selekcijski kriterij bio je osobni izbor oplemenjivača, potom masa zrna/biljci, a najslabiji standardna bulk populacija. Preporučuje se selekciju na urod zrna provoditi na svojstva i komponente uroda velike i osrednje nasljednosti, s manjim intenzitetom selekcije u ranim generacijama od intenziteta primijenjenog u ovim istraživanjima, te u daljnjim istraživanjima provjeriti korelaciju mase zrna po biljci s urodom zrna po jedinici površine u proizvodnim uvjetima.
Ključne riječi: ozima pšenica, roditelji F1 - F4 generacije, selekcijski kriteriji, varijabilnost, heritabilnost, dobit od selekcije, masa zrna po biljci, komponente uroda zrna, visina vlati, žetveni indeks.
Summary: Progenies of winter wheat of the F1 to F4 generations and parents of three crossing combinations were investigated in the same year of the investigation in a thick plant stand (500 kernels per m2) which it typical for large scale production. For each crossing combination we formed the F4 populations by a) visual selection, b) by selection for the largest number of spike per plant, c) by selection for the lowest stem, d) by selection for the largest number of kernels per spike, e) by selection for the largest kernel weight, f) by selection for the largest kernel weight per plant, g) by selection for plants with the highest harvest index and h) as a bulk population.
The selection for the F4 generation was performed in a thin (100 kernels per m2) and thick plant stand (500 kernels per m2) from the F3 bulk population and the F3 generation of selected plants. We have estimated variability, heritability, dominance degree, genetic gain and achieved gain from selection in the following traits: the stem height, the number of fertile tillers, the number of kernels, the weight of one kernel per spike, the weight of kernels per plant and the harvest index. Also, certain selection criteria were evaluated in each crossing combination. The kernel weight and the number of fertile tillers per plant were found to have the highest, whereas the steam height was found to have the lowest variation coefficient.
Regarding the dominance degree, partial dominance to superdominance was estimated for the taller stem and a higher kernel weight, while for other traits under observation, the estimates have shown dominance to superdominance in one direction and dominance and superdominance in another direction. The largest heritability was found in the stem height, while it varied considerably in other traits observed. Genetic gain was estimated to be very high for the stem hight, furthermore, high for kernel weight per plant and medium for the number of kernels per spike. The direct selection for a certain trait has had major influence on reducing the stem height and increasing the kernel weight, and also it affected largely increasing the kernel weight per plant.
The best individual criteria in selection for the largest kernel weight per plant are the direct selection for this trait, the visual choice of the breeder and selection for the largest weight for one kernel. Generally, the best individual selection criterion for all traits under observation was the visual selection of the breeder, furthermore, selection for the kernel weight per plant, while the weakest criterion was standard bulk population. Selection for grain yield per plant should perform for the traits and yield components which show large or medium heritability. The intensity of selection in early generations should be lower than the intensity applied in these investigations. Correlation of the kernel weight per plant and grain yield per plot unit should be checked in further investigations in large scale production.
Key words: winter wheat, parents, the F1 to F4 generations, selection criteria, variability, heritability, gain of selection, kernel weight per plant, yield components, tiller height, harvest index.
Doktor biotehničkih znanosti - agronomija
mentor: Zdravko Martinčić-Jerčić; Komisija za ocjenu: Vinko Kozumplik, Zdravko Martinić-Jerčić, Josip Kovačević; Komisija za obranu: Vinko Kozumplik, Zdravko Martinić-Jerčić, Josip Kovačević; datum obrane: 17.09.1996.; datum promocije
Sveučilište u Zagrebu, Agronomski fakultet, Zagreb, 1996
Bibliografija: str. 88-102
Summary
Keywords: Pšenica -- Selekcija