A study of variability of alfalfa yield components using principle component analysis

Abstract

The aim of this paper was to examine the genetic divergence of 30 alfalfa genotypes (tab. 1). The study was carried out during 2001-2003 at Rimski Šančevi and included seven cuts. Genotype variability was analyzed using eight quantitative traits, namely green forage yield, dry matter yield, plant height, shoot (stem) number per plant, intrernode length and number, leaf contribution to yield, and stem diameter. Principal component analysis was used to determine the structure of the sources of variability. Four principal components explaining 95.5 % of the genotype variability were chosen for interpretation (tab. 2). The greatest communality with the first principal component was found for internode length, plant height and leaf contribution to yield, which were all highly interdependent. The second principal component was defined by the agronomically most important traits, namely green forage yield, dry matter yield and stem number per plant. The third and fourth principal components were defined by internode number and stem diameter.

Cilj rada je bio da se ispita genetička divergentnost 30 geno tipova lucerke tokom 2001-2003. u sedam otkosa, na lokalitetu Rimski Šančevi. Varijabilnost genotipova je analizirana za osam kvantitativnih osobina prinos zelene krme i suve materije, visinu biljaka, broj izdanaka (stabljika) po biljci, broj i dužina internodija, udeo lišća u prinosu i prečnik stabljika lucerke, kao i da se oceni koja od ispitivanih osobina najviše doprinosi međusobnom diferenciranju genotipova. Metodom glavnih komponenata određena je struktura izvora varijabilnosti. Za interpretaciju su odabrane četiri glavne komponente koje objašnjavaju 95,5% varijabilnosti ispitivanih genotipova. Najveći komunalitet (% udeo varijanse) sa prvom glavnom komponentom imaju dužina internodija, visina biljaka i udeo lišća koje su u visokoj međuzavisnosti. Druga glavna komponenta definisana je agronomski najvažnijim osobinama: prinosom zelene krme, prinosom suve materije i brojem stabljika po biljci. Treća i četvrta glavna komponenta su definisane brojem internodija i prečnikom stabljika.