Association between trichome characters and agronomic traits inSolanum tuberosum (L.)XS. berthaultii (hawkes) hybrids

In 1977, a program to develop potato cultivars with insect resistance based on the glandular trichomes found onSolanum berthaultii was initiated at Cornell University. Associations between agronomic and trichome characters were suspected due to difficulties in selecting hybrid plants with both insect resistance and acceptable agronomic characteristics. Plants from backcrosses and intercrosses were studied. A strong association between the presence of B trichome droplets and undesirable agronomic characteristics was established in backcrossed generations. The backcross plants bearing droplets produced significantly lower yields, fewer tubers, later maturing plants, and poorer foliage and tuber appearance than their sibs without the droplets. In intercrosses, no associations were found. Good MEBA scores were seldom found in backcrossed plants without B droplets. The associations observed are speculated to be due to linkage or structural genomic differentiation between the genomes of the species involved in these populations.