Research Notes : United States : Response of tolerant and susceptible soybean cultivars to Columbia lance nematode

Columbia lance nematode, CLN [Hoplolaimus columbus Sher], is a migratory endo-and ectoparasite of soybean and commonly causes yield reductions of up to 30% in tolerant cultivars. Complete crop failure may occur on moisture-stressed or susceptible cultivars. First recognized as a major parasite of cotton and soybean in 1967 (Fassultiotis et al., 1968), CLN now infests a large portion of the coastal plain of South Carolina, Georgia, and North Carolina. .pd

Evaluation of a mountain pine beetle infestation, Stoney Creek, Ninemile District, Lolo National Forest, 1975

Mountain pine beetle populations reached epidemic levels in 1972 in the Stoney Creek drainage, Ninemile District, Lolo National Forest, Montana. A total of 8,082 trees with an estimated volume loss of 34,356 board feet has occurred from 1972 to 1974. Buildup ratio was 1:1.2 from 1972 to 1973, and 1:1.8 from 1973 to 1974. Losses are expected to increase in 1975. Commercial thinning is recommended in unthinned stands

SNP assay to detect the ‘Hyuuga’ red-brown lesion resistance gene for Asian soybean rust

Asian soybean rust (ASR), caused by Phakopsora pachyrhizi Syd., has the potential to become a serious threat to soybean, Glycine max L. Merr., production in the USA. A novel rust resistance gene, Rpp?(Hyuuga), from the Japanese soybean cultivar Hyuuga has been identified and mapped to soybean chromosome 6 (Gm06). Our objectives were to fine-map the Rpp?(Hyuuga) gene and develop a high-throughput single nucleotide polymorphism (SNP) assay to detect this ASR resistance gene. The integration of recombination events from two different soybean populations and the ASR reaction data indicates that the Rpp?(Hyuuga) locus is located in a region of approximately 371 kb between STS70887 and STS70923 on chromosome Gm06. A set of 32 ancestral genotypes which is predicted to contain 95% of the alleles present in current elite North American breeding populations and the sources of the previously reported ASR resistance genes (Rpp1, Rpp2, Rpp3, Rpp4, Rpp5, and rpp5) were genotyped with five SNP markers. We developed a SimpleProbe assay based on melting curve analysis for SNP06-44058 which is tighly linked to the Rpp?(Hyuuga) gene. This SNP assay can differentiate plants/lines that are homozygous/homogeneous or heterozygous/heterogeneous for the resistant and susceptible alleles at the Rpp?(Hyuuga) locus

Effects of Liberal Concentrate Feeding on Health, Reproductive Efficiency, Economy of Milk Production, and Other Related Responses of the Dairy Cow

An increasing supply of grain at lower prices has en- couraged dairymen to feed more concentrates to cows bred for high production. Some dairymen have experienced phenomenal changes in levels of production resulting from liberal grain feeding, but most of these were due to a change from low to moderate, or from moderate to high rates of grain feeding. Many such situations involved in- dividual cows of exceptional appetite and unusual toler- ance to digestive stress, as well as special catering by an expert dairyman