Genotypic and phenotypic relationship between physiological and grain yield related traits in four maize (Zea mays L.) crosses of subtropical climate

Abstract

A study to estimate genotypic and phenotypic correlations among physiological and grain yield related traits in four maize crosses, derived from mating of four inbred lines of subtropical climate, was conducted during 2006 and 2007 at Cereal Crops Research Institute (CCRI) Pirsabak, Nowshera, Pakistan. Physiological plant traits included days to 50% silk emergence, leaf area, plant height and days to maturity while ear length, number of kernel rows ear-1, 100 grain weight and percent shelling were included as grain yield related traits. The association of these physiological traits with grain and stover yields was also investigated in this study. Days to silk and maturity were significantly and negatively associated with ear length both genotypicaly and phenotypicaly in two crosses. However, in the other two crosses, this association was non significant with negative magnitudes regarding ear length, grain yield with other related traits and stover yield. Leaf area and plant height exhibited positive and significant relationship with grai and stover yields and all other yield associated traits. Based on the results of the current study, it was concluded that association between physiological traits and grain yield related traits was mostly positive for leaf area and plant height. However, days to 50% silking and days to maturity exhibited negative association with most of the grain yield related traits. It can be inferred that positive relationship indicated favorable genes controlling these traits which were present in the parents and might be utilized for the improvement of these lines in future breeding programs. Key words: Genotypic and phenotypic relationship, physiological and grain yield related traits, generations, subtropical maize.