Thirty-five populations of Heterodera glycines and populations of 15 other Heterodera, Globodera, and Punctodera species were studied morphometrically and some were compared serologically. There was a wide range of each measurement within each nematode population. Except for one soybean cyst nematode population from Indiana, which was a tetraploid and considerably larger than the others, morpho...

High-performance liquid chromatography and Sinorhizobium fredii USDA191 nodC-lacZ gene fusion were used to monitor changes in the isoflavonoid content of soybean roots infected with Heterodera glycines isolate TN1. Isoflavonoid concentrations in infected roots of both H. glycines-resistant Hartwig and susceptible Essex soybean were two to four-fold higher than those of uninfected roots 2 and 3 ...

The Effect of Drought Stresses, Fusarium Culmorum and Heterodera Filipjevi their Interactions on the Expression Pattern Transcription Factor Gene NAC69-3 in Bread Wheat

Soybean cyst nematode (Heterodera glycines, SCN) is the most harmful pathogen of soybean (Glycine max (L.) Merr.) worldwide. In 2016, a new soybean-parasitic nematode, Heterodera sojae (the white nematode) was found parasitizing roots plants in Korea. To investigate distribution and population density H. sojae, 943 soil samples were collected from fields all nine provinces Korea 2017 to 2018. C...

The relative DNA content of hypodermal nuclei of preparasitic, 2nd-stage larvae was determined cytophotometrically in 19 populations belonging to 13 species of Meloidogyne, Heterodera and Meloidodera. In Meloidogyne hapla, M. arenaria, M. incognita and M. javanica, total DNA content per nucleus is proportional to their chromosome number, indicating that chromosomal forms with high chromosome nu...

Fructose-bisphosphate aldolase (EC 4.1.2.13) is a key enzyme in glycolysis. We have characterized full-length coding sequences for aldolase genes from the cyst nematodes Heterodera glycines and Globodera rostochiensis, the first for any plant-parasitic nematode. Nucleotide homology is high (83% identity), and the respective sequences encode 40 kDa proteins with 89% amino acid identity. Genomic ...

Cytological study revealed that maturation of oocytes of Heterodera betulae is by regular meiosis and reproduction is by parthenogenesis. Restoration of the somatic chromosome number occurs after telophase II and before egg pronucleus formation, in the absence of a mitotic apparatus through a type of endomitotic division. The haploid chromosome number is 12 (2n = 24) in 95% of the female nemato...

Thirteen soybean plant introduction (PI) lines, selected for their apparent susceptibility to Heterodera glycines, were compared with cultivar Lee 74 as hosts of H. glycines races 1, 2, 3, and 4. Race 3 produced the highest average number of females of the four races. Compared to Lee 74, more (P = 0.05) females of H. glycines race 1 were extracted from eI 274420, PI 274423, and PI 317333; PI 86...

Eighteen soybean fields, six each with race 3, race 4, or Bedford population of Heterodera glycines, were selected for testing of host variability. Each field was divided into three sections, and a bulk soil sample was taken from each section. The 54 bulk soil populations (BSP) and 270 single cyst populations (SCP) were subjected to race determination tests. Tests of the 18 BSP and 90 SCP from ...