Genetic and Phenotypic Variability of Yield Components in Wheat (Triticum aestivum L.)

Abstract

The heritability, phenotypic variability and components of variance for spike length and number of spikelets per spike have been studied in 50 cultivars from different selection centers all over the world. The experiment was performed in randomized block design in three replications on the experimental field in two years. A total number of 60 plants have been analyzed in the full maturity stage. Average estimated values of spike length and number of spikelets per spike differed significantly among years and among cultivars. The highest average value of spike length had Mironovskaya 808 cultivar (x =14.5 cm), and the lowest value was found in Etoille de Choisy (x=8.1 cm) and San Pastore cultivar (x=8.2). During investigated periods the highest average value for number of spikelets/spike had Sava cultivar (x=28.2), and the lowest value expressed Frontana cultivar (x=19.2). The average variation coefficient for spike length was 8.0%, and for number of spikelets per spike was 7.5%. The lowest variability for spike length was established in Pernel cultivar (V=4.8%) and the highest in Lepenica cultivar (V=12.9%). The coefficient of variation for number of spikelets per spike ranged from 4.7% in Bankut 1205 to 12.4% in Norin 10 cultivar. The obtained herita bility values in broad sense were fairly high for spike length (96.4%) and number of spikelets per spike (79.1%). Phenotypic analysis of variance indicated that genetic variance took a larger portion of the total phenotypic variability for spike length (81.82%) and for number of spikelets per spike (57.36%) than influence of environmental factors on expressing of analyzed yield components.

U radu je proučavana genetička i fenotipska varijabilnost dužine klasa i broja klasića po klasu kod 50 genetički divergentnih sorti pšenice. Istraživanja su obavljena u poljskom ogledu izvedenom po slučajnom blok sistemu u tri ponavljanja, tokom dve godine. Analize su uradjene na uzorku od 60 biljka u punoj fazi zrelosti. Utvrdjene su signifikantne razlike za dužinu klasa i broj klasića po klasu izmedju sorti i godina. Najveća vrednost dužine klasa ustanovljena je kod sorte Mironovskaya 808 (14,5 cm), a najmanja kod sorti Etoille de Choisy (8,1 cm) i San Pastore (8,2 cm). Sorta Sava je imala najveći broj klasića po klasu (28,2), a najmanja vrednost za ovo svojstvo utvrdjena je kod Frontane (19,2). Prosečna varijabilnost dužine klasa (V = 8,0%) i broja klasića po klasu (V = 7,5%) bila je dosta niska. Najmanju varijabilnost za dužinu klasa ispoljila je sorta Pernel (V = 4,8%), a za broj klasića po klasu sorta Bankut 1205 (V = 4,7%). Utvrdjena je visoka vrednost za heritabilnost u širem smislu za dužinu klasa (h2 = 96,4%), a nešto niža vrednost za broj klasića po klasu (h2 = 79,1%). Analizom komponenti fenotipske varijanse ustanovljeno je da genetički faktori imaju veći udeo u ispoljavanju dužine klasa (81,82%) i broja klasića po klasu (57,36%) od faktora spoljne sredine