Association analysis among morphological and physiological traits of grain yield in wheat and meteorological parameters

Abstract

In order to identify potential traits determining yield under terminal heat stress during grain filling stages, correlation and path coefficients analyses were conducted to study character associations among 25 morphological and physiological traits in a set of genetically divergent 36 bread wheat genotypes under normal and late sown conditions. Grain yield depicted positive association with grain weight (GW), grains/spike (G/S), biological yield (BY), harvest index (HI) under normal (NS) and late sown (LS) conditions, GGR-3 (grain growth rate at 28 days after anthesis) in LS and negative association with DM (days to maturity) , HU (heat units) and PTU (photothermal unit) in NS and with ChA-1(CHB “a” at anthesis), CHB “a”-1 (total CHB at anthesis) and CHB “a”-2 (total CHB at 28 days after anthesis) in LS. Path coefficient analysis revealed that out of eight characters significantly related to yield under normal sown conditions, PTU, harvest index, biological yield and grains per spike directly affected the grain yield in positive direction. On the basis of strong association with yield and marked direct influence on yield, the numbers of grains are considered to be first order yield components and ought to have top priority in selection under normal sown conditions. Under late sown conditions BY, harvest index (HI), CHB “a”-1 and grain weight had direct positive effect but the grains per spike exhibited negative direct effect despite of the fact that it possessed a positive significant correlation with grain yield. Based on results, it is suggested that high numbers of grains and high grain weight should be given priority for selection of high yielding genotypes in NS and LS, respectively.

Keywords

• Wheat
• correlation
• path coefficient
• character association selection criteria
• stay green
• chlorophyll, grain yield,