Occurrence of Seed Coat Mottling in Soybean Plants Inoculated with Bean pod mottle virus and Soybean mosaic virus.

Soybean seed coat mottling often has been a problematic symptom for soybean growers and the soybean industry. The percentages of seed in eight soybean lines with seed coat mottling were evaluated at harvest after inoculating plants during the growing season with Bean pod mottle virus (BPMV), Soybean mosaic virus (SMV), and both viruses inside an insect-proof cage in the field. Results from experiments conducted over 2 years indicated that plants infected with BPMV and SMV, alone or in combination, produced seed coat mottling, whereas noninoculated plants produced little or no mottled seed. BPMV and SMV inoculated on the same plants did not always result in higher percentages of mottled seed compared with BPMV or SMV alone. There was significant virus, line, and virus-line interaction for seed coat mottling. The non-seed-coat-mottling gene (Im) in Williams isoline L77-5632 provided limited, if any, protection against mottling caused by SMV and none against BPMV. The Peanut mottle virus resistance gene Rpv1 in Williams isoline L85-2308 did not give any protection against mottling caused by SMV, whereas the SMV resistance gene Rsv1 in Williams isoline L78-379 and the resistance gene or genes in the small-seeded line L97-946 gave high levels of protection against mottling caused by SMV. The correlations (r = 0.77 for year 2000 and r = 0.89 for year 2001) between virus infection of the parent plant and seed coat mottling were significant (P = 0.01), indicating that virus infection of plants caused seed coat mottling.

Podiatric surgical considerations in the older patient.

The goal of podiatric surgery in the older patient should be pain management with the highest degree of functional restoration. Thorough preoperative analysis, meticulous surgical technique, and careful postoperative planning are necessary to ensure a favorable surgical result. Each planned procedure must coincide with the specific needs of the individual patient while conforming to the body's physical limitations. A complete medical examination with laboratory studies is indicated due to the elderly patient's inherent diminished physical status. When the patient is deemed a proper candidate for surgery, the medical team, family, and friends should be consulted regarding immediate and long-term postoperative care. Strict adherence to these principles is in the best interest of both the practitioner and the older patient.

Sinus tarsi syndrome in a patient with talipes equinovarus.

The literature reports that 70% of the cases of sinus tarsi syndrome are post-traumatic, following an inversion sprain, and that 30% result from inflammatory disorders, such as rheumatoid arthritis, ankylosing spondylitis, and gouty arthritis. However, in the case presented, talipes equinovarus deformity and sinus tarsi syndrome coexisted. One of the corrective goals in the management of the talipes equinovarus deformity is the realignment of the articulation between the medial plantarly deviated talar head and the anteromedial segment of the calcaneus. The calcaneus must be rotated from a plantarflexed position into a dorsiflexed position. The posterior tubercle will be moved down and in, with the anterior process moved up and out away from the talar head. By correcting the plantarflexed varus attitude of the calcaneus, it is put in a valgus position that often closes down the sinus tarsi upon weightbearing. This compression may result in pain over the lateral aspect of the midfoot with hindfoot instability, as seen in the case presented. As a result of the abnormal anatomical relationship of the talus and calcaneus, the patient developed severe pain in the sinus tarsi. Based on the medical history and present postoperative results, the authors find a long-term sequela of talipes equinovarus deformity to be sinus tarsi syndrome.

Composition and activity of the photosynthetic apparatus in temperature-sensitive mutants of higher plants.

Six nuclear mutants of corn, six of soybean, and seven of cotton displayed low temperature-induced virescence when grown in controlled environments. For the group of plants studied, an increase in leaf chlorophyll a/b ratio was correlated with a temperature-sensitive biosynthetic sequence leading to a reduction in total chlorophyll content. These pigment alterations were reflected in the composition and quantity of the two major chlorophyll-protein complexes of chloroplast membranes. Changes in the amount of the major light-harvesting chlorophyll-protein complex was a prime consequence of the nuclear mutations. A decrease in the light-harvesting chlorophyll component of the light reaction centers of the leaf may account for the decrease in size of the photo-synthetic unit frequently noted in chlorophyll-deficient mutants. Variations in the concentration of the chlorophyll-protein complexes in the chloroplast lamellae may be causally related to variations in CO(2) compensation points of mutant soybean and cotton plants.

Crop rotation effects on population densities of ectoparasitic nematodes.

The influence of rotation crop species on population densities of ectoparasitic nematode species common to soybean and corn fields of the North-Central region of the USA was studied for 5 years in 16 field blocks rotated to corn, soybeans, oats, wheat, and forage mixtures. Each block was sampled each year between mid-July and mid-August. High populations of Helicotylenchus pseudorobustus were maintained in all crops, especially corn. Tylenchorhynchus martini and Xiphinema americanum also developed with all crops, but a second year of corn depressed densities of both species. Paratylenchus projectus densities were high on soybeans and on forage consisting primarily of legumes.

Effect of soil type on population densities of nematodes in soybean rotation fields.

The effect of soil type on population densities of plant parasitic nematode species in 17 field blocks of four different soil types rotated to corn, soybeans, wheat, and forage mixtures was investigated during a generally droughty 5-year period. High densities of Helicotylenchus pseudorobustus were found in dark silty clay loams. Highest densities of Tylenchorhynchus acutus were also in one of the dark-colored silty clay loams. Light-colored silt loams favored development of Paratylenchus projectus, which developed poorly in the darker soils. Comparable densities of Xiphinema americanum were found in all soils and on all crops, regardless of soil type. Tylenchorhynchus martini, although present, did not build up in any of the soils. Populations of Pratylenchus species were generally low in the rotated blocks of all soil types.

Community Structure of Plant-parasitic Nematodes Related to Soil Types in Illinois and Indiana Soybean Fields.

Comparisons of plant parasitic nematode populations using a resemblance equation and community ordination showed that community structure tends to be similar on dark-colored, highly productive soybean soils throughout Indiana and Illinois. On lighter-colored soils community structures differed somewhat from those of darker soils and from each other.