Efficiency of Single Trait Selection for Improving Yield and Earliness in Varietal Maintenance of Giza 90 Egyptian Cotton

Abstract

The present study was carried out at Shandaweel Res. Sta. Sohag, Cotton Res. Inst., (ARC), during the three summer seasons of 2013 -2015. The basic materials were selfed seeds of 60 single plants selected from the breeding nursery of renewal and maintenance of Giza 90 (the same materials used for producing the nucleolus of G.90). The main objective of this work was to study the possibility of selection elite high yielding plants characterized by the same fiber properties of Giza 90. To attain this goal, single trait selection for lint yield, lint percentage and earliness was applied for two cycles. Average of the ten selected families indicated that selection for LY/P ranked the first and improved LY/P by 20.30% of the check strain followed by selection for days to first flower method (15.82%), and LY/P restricted by DFF (11.54%). Generally, single trait selection is an effective method to improve selection criterion. The observed genetic gain indicated that single trait selection resulted in several superior families significant out yielded the check strain and better in one or more of the three main fiber properties; fineness, strength and Upper Half Mean length. Therefore, the official method of maintaining and renewing Egyptian cotton varieties should be modified to allow selection for yield beside preserving fiber properties.