Mm. Mota et Jd. Eisenback, MORPHOLOGY OF FEMALES AND CYSTS OF GLOBODERA-TABACUM TABACUM, G-T-VIRGINIAE, AND G-T-SOLANACEARUM (NEMATA, HETERODERINAE), Journal of nematology, 25(2), 1993, pp. 136-147
Detailed morphological comparisons with light and scanning electron mi
croscopy were made of white females and cysts of several isolates of G
lobodera tabacum sspp. tabacum (GTT), virginiae (GTV), and solanacearu
m (GTS). Observations focused on body shape, anterior region including
head shape, lip pattern, stylet morphology, and the terminal area in
females; and body shape and terminal area of cysts. The most useful ch
aracters to separate the three subspecies were forms of the female bod
y, cyst, stylet knobs, tail region, perineal tubercles, anal-fenestral
ridge patterns, and the distinctiveness of the anus. GTT is character
ized by having round females and cysts, sharply back sloped stylet kno
bs, clumped perineal tubercles in the vulval region, tight parallel ri
dges in the cyst anal-fenestral region, and a uniformly conoid tail re
gion. GTV is characterized by its ovoid to ellipsoid female and cyst s
hape, the ''Dutch shoe'' shape of the dorsal stylet knob, the more dis
persed perineal tubercles, a maze-like pattern of ridges in the anal-f
enestral region, and an indistinct anus. GTS is characterized by its o
void to ellipsoid female and cyst shape, moderately backward sloped st
ylet knobs, more widely separated ridges, a distinct anus, and a usual
ly crescent shaped tail region. Much variability in,shape and patterns
is visible among all the isolates of the different subspecies. Tuberc
les in the neck, as well as bullae, are reported, and their taxonomic
value is discussed.