Single Nucleotide Polymorphism Analysis Using KASP Assay Reveals Genetic Variability in .

This study employed single nucleotide polymorphisms (SNPs) to determine the genetic variability present in 26 isolates of from Louisiana, Mississippi, Arkansas, South Carolina, Georgia, Hawaii, and Alabama. Genomic DNA from reniform nematode was extracted and increased quantitatively using the process of whole genome amplification. More than 162 putative SNPs were identified, 31 of which were tested using a KASP kompetitive allele-specific PCR genotyping assay.

The Elusive Search for Reniform Nematode Resistance in Cotton.

The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) has emerged as the most important plant-parasitic nematode of cotton in the United States cotton belt. Success in the development of reniform nematode-resistant upland cotton cultivars (Gossypium hirsutum L.) has not been realized despite over three decades of breeding efforts.

Site specific nematode management-development and success in cotton production in the United States.

Variability in edaphic factors such as clay content, organic matter, and nutrient availability within individual fields is a major obstacle confronting cotton producers. Adaptation of geospatial technologies such global positioning systems (GPS), yield monitors, autosteering, and the automated on-and-off technology required for site-specific nematicide application has provided growers with additional tools for managing nematodes. Multiple trials in several states were conducted to evaluate this technology in cotton.

Suppression of Rotylenchulus reniformis 122-cm Deep Endorses Resistance Introgression in Gossypium.

Nine sources of resistance to Rotylenchulus reniformis in Gossypium (cotton) were tested by measuring population density (Pf) and root-length density 0 to 122 cm deep. A Pf in the plow layer less than the autumn sample treatment threshold used by consultants was considered the minimum criterion for acceptable resistance, regardless of population density at planting (Pi). Other criteria were ample roots and a Pf lower than on the susceptible control, as in pot studies.

Vertical Distribution of Rotylenchulus reniformis in Cotton Fields.

The possible impact of Rotylenchulus reniformis below plow depth was evaluated by measuring the vertical distribution of R. reniformis and soil texture in 20 symptomatic fields on 17 farms across six states. The mean nematode population density per field, 0 to 122 cm deep, ranged from 0.