DEVELOPMENT OF HETERODERA-GLYCINES ICHINOHE ON SOYBEAN, GLYCINE-MAX (L) MERR, UNDER GNOTOBIOTIC CONDITIONS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 15  (2) , 272-281
Abstract
The life cycle of the soybean cyst nematode, Race 3 (SCN 3), H. glycines Inchinohe, was determined from observations of the developmental stages on soybean G. max cv. Kent root explants under gnotobiotic conditions at 25.degree. C. Approximately 51% of the 2nd-stage larvae penetrated the root 1 day after inoculation (DAI). Third-stage larve appeared 4 DAI, became sexually differentiated 5 DAI, and protruded from the root tissues 6 DAI. Fourth-stage males and females were observed 7 DAI. Ensheathed adult males were observed at 9 DAI and exsheathed to free adults at 11 DAI. The 4th-stage female became an adult at 10 DAI. Males entwined around the gelatinous sac of the female at 12 DAI and were assumed to be mating. Some males actually penetrated and were enveloped by the gelatinous sac. The female-to-male sex ratio ranged from 2.3-9.5:1. First- and 2nd-stage larvae were observed in the egg 17 and 19 DAI, respectively. The life cycle of the SCN 3 was completed 21 DAI upon hatching of the eggs and emergence of 2nd-stage larvae. The average number of eggs in the cyst body and gelatinous sac, was 210 and 187, respectively.