Inter-Relationship of Leaf Photosynthesis, Specific Leaf Weight and Leaf Anatomical Characters in Soybean

In a field trial, 27 divergent soybean cultivars were evaluated for leaf photosynthesis (Pn), specific leaf weight (SLW), and leaf and palisade thickness at two reproductive growth stages i.e. R1 (appearnee of first Hower) and R5(begining of seed fill). A wide range of genotypic variability was observed for all the characters studied. At R5 stage, Pn gave a strong positive genotypic correlation with SLW (r=0.71), leaf thickness (r=0.54) and palisade thickness (r=0.52). The SLW in turn was significantly and positively associated with leaf and palisade thickness at this growth stage. A strong positive association was also observed between SLW at RS stage and grain yield (r=0.63). Owing to high proportion of genetic variance and a high degree of positive association, SLW at R5 stage is suggested to be a simple selection criterion for evaluation of a large number of soybean genotypes for Pn. Donors for desirable physiological and morphoanatomical characters were identified for use in breeding programmes.