The Influence of Potato Cultivar on Lipid Content and Fecundity of Bolivian and British Populations of Globodera rostochiensis.

The influence of host cultivar on the lipid levels provided by a female to her progeny was investigated with Oil Red O stain and a quantitative image analyzer. A population of Globodera rostochiensis was multiplied at Toralapa Field Station in Bolivia on 25 different potato cultivars grown in that country. The mean neutral lipid content of newly formed second-stage juveniles varied significantly with cultivar over a 200% range. The corresponding range was only 18% and 28% for the same Bolivian and a UK population of G. rostochiensis, respectively, when both completed reproduction concurrently on 10 pot-grown European cultivars in the United Kingdom. Egg numbers per female varied with host for Bolivian cultivars that lack known partial resistance to Globodera spp. There was a 15-fold range between the most and least fecund nematode-host combinations (Kosi and Gendarme). The Bolivian G. rostochiensis population showed only a 2-fold range in mean eggs per cyst when grown on European cultivars in the UK. The fatty acid profiles of lipids from Bolivian G. rostochiensis cysts reared on Bolivian potato cultivars were dominated by C(20) (37-64%) and C(18) (28-46%) fatty acids and ranged from C(14) to C(22). The three major fatty acids detected were C(20:4:), C(20:1), and C(18:1). Few differences between cultivars were observed. For a UK population of G. rostochiensis reared on ssp. tuberosum, higher relative percentages of C(18) and monounsaturated fatty acids and lower relative percentages of C(20) and polyunsaturated fatty acids were found.