PLANT ROOTS WERE MECHANICALLY INJURED OR SUBJECTED TO NEMATODE PARASITISM TO TEST THE MODEL OF HOST DAMAGE BY TWO NEMATODE SPECIES: y = m' + (l - m')c'z(P)z(P) for y 1.0, where m' = m + (m - m) (1 - y)/[(1 - y) + (l - y)] and c' = (z(-T) + z(-T))/2. Damage functions for greenhouse-grown radish plants (cv. Cherry Belle) mechanically injured with small or large steel n...

Meloidogyne incognita, M. arenaria, M. hapla, and M. javanica were distinguishable from each other by isoelectric focusing (IEF) of nematode egg proteins. Proteins extracted from larvae and adults of Hoplolaimus columbus and from eggs of Heterodera glycines had distinctive profiles, also. Protein profiles from eggs, preparasitic larvae and egg-laying adults of M. incognita showed differences. I...

Host suitability of olive cultivars Arbequina and Picual to several plant-parasitic nematodes was studied under controlled conditions. Arbequina and Picual were not suitable hosts for the root-lesion nematodes Pratylenchus fallax, P. thornei, and Zygotylenchus guevarai. However, the ring nematode Mesocriconema xenoplax and the spiral nematodes Helicotylenchus digonicus and H. pseudorobustus rep...

Thirty-six cultigens of tomato were evaluated for resistance against Meloidogyne javanica and four races of M. incognita with standards and parameters adopted by the International Meloidogyne Project. Most cultigens were susceptible to the nematodes, including some that were previously reported to be resistant to these nematodes. Ten accessions, namely Pusa-120, Calmart VFN, Panjab 6.NR-7, EC17...

Root-knot nematodes (Meloidogyne spp.) are a significant problem in potato (Solanum tuberosum) production. There is no potato cultivar with Meloidogyne resistance, even though resistance genes have been identified in wild potato species and were introgressed into breeding lines. The objectives of this study were to generate stable transgenic potato lines in a cv. Russet Burbank background that ...

A survey was conducted to determine the frequency and abundance of Meloidogyne spp. in tomato production sites located in Baix Llobregat County, Barcelona, Spain. Forty-five sites were sampled before planting and at harvest from February to October, 1991. Meloidogyne spp. occurred in 49% of the sites sampled. Preplant population densities ranged from 10 to 220 (x = 110)juveniles/ 250 cm(3) soil...

Resistance to the root-knot nematodes Meloidogyne spp. would be a valuable attribute of lettuce Lactuca sativa L. cultivars grown in tropical regions. The looseleaf lettuce 'Grand Rapids' is resistant to both M. incognita and M. javanica. Resistance to M. incognita has a high heritability, under the control of a single gene locus, in which the 'Grand Rapids' allele, responsible for resistance (...

Tall fescue grass cultivars with or without endophytes were evaluated for their susceptibility to Meloidogyne incognita in the greenhouse. Tall fescue cultivars evaluated included, i) wild-type Jesup (E+, ergot-producing endophyte present), ii) endophyte-free Jesup (E-, no endophyte present), iii) Jesup (Max-Q, non-ergot producing endophyte) and iv) Georgia 5 (E+). Peach was included as the con...

While sexual reproduction is generally thought to be, evolutionarily speaking, a good idea, there are a small number of organisms that are testament to the contrary. The root-knot nematodes Meloidogyne incognita, M. javanica, and M. arenaria reproduce clonally using mitotic parthenogenesis but have a broader host range, a wider geographical distribution, and a greater agricultural impact than t...