Digital imaging of morphometric characteristics of pigeon pea (Cajanus cajan) for genotype discrimination

Digital seed imaging was utilized in this study to evaluate the morphometric characteristics of pigeon pea for genotype discrimination.  One hundred seeds in each of the pigeon pea accession were subjected to digital imaging analysis using the WinSEEDLE™ software to  differentiate the seed metric characters. Seeds were placed on a lighting hood and were automatically analyzed by the scanner and the  image of the seed was recorded by the WinSEEDLE™. The procedure was repeated three times. The parameters observed were projected  area, straight length, curve length, straight width, curve width, volume circle, and projected perimeter. Data collected were subjected to  analysis of variance, principal component analysis and product moment correlation coefficients between the parameters were obtained.  The result revealed that the pigeon pea accessions were highly variable in all the seed metric traits evaluated. Accessions NSWCC-34 and  NSWCC-32 showed superiority values in most of the seed metric traits evaluated. Accessions NSWCC-32 had 28.35 mm2 , 6.99 mm, 7.37  mm, 5.23 mm and 5.28 mm in seed projected area, seed straight length, curve length, straight width and curve width, respectively while NSWCC-34 recorded 28.34 mm2 , 6.75 mm, 7.10 mm, 5.22 mm and 5.27 mm for the same evaluated traits. Most of the seed traits showed  significant positive and strong association. The study, therefore, recommends that accessions NSWCC-34 and NSWCC-32 as well as those  traits with high contribution to the major variation (seed projected area, seed straight length, curve length, straight width, curve width  and volume circle) could be included in the seed improvement programme for improved seed quality in pigeon pea.