Pubescence of four bean genotypes

Abstract

A study was conducted to describe the pubescence in four genotypes (lines A-429, DOR-303, 27-R and PC-50) of the common bean, Phaseolus vulgaris L., known to vary in field reaction to bean golden mosaic. Only two types of non-glandular trichomes were observed in the lines tested. The trichomes were of the unciform and acerate types. Significant differences were detected between the abaxial and axial surfaces of the leaves. Trichomes varied both in size and density depending on the type of leaf. Line A-429 displayed the highest pubescence and also showed the highest number of trichomes per square centimeter. Line DOR-303 showed the highest density of unciform trichomes, but of smaller size than those of the other four limes. More acerate than unciform trichomes were detected on the underside of the leaf of line PC-50. In general, line 27-R was the line with the highest trichome density and also the line that with greater regularity possessed both types of trichomes.