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Marek's disease (MD) vaccines representing serotypes 2 (SB-1 strain of MD virus) and 3 (FC-126 strain of turkey herpesvirus) were administered to 1-day-old MD-susceptible chicks that either were free of antibodies or carried maternally derived antibodies against SB-1, FC-126, or a serotype-1 MD virus, CU-2 strain. Homologous antibodies delayed the development of vaccine virus viremias and inhibited vaccinal immunity, as judged by protection against challenge with the virulent JM-10 strain of MD virus 7 days postvaccination. Heterologous antibodies had little effect on vaccine responses. Antibodies were shown to interfere with both cell-associated and cell-free vaccine virus.

A highly antigenic isolate of Mycoplasma gallisepticum (MG) was utilized in the production of an inactivated, oil-emulsified MG bacterin (MGB). Laboratory tests indicated that the bacterin was capable of protecting chickens from clinical signs of MG caused by intrasinus challenge with the R, S-6, PG-31, or 1150 strain of MG. Vaccinated turkeys also were protected from clinical signs of disease when challenged with MG. Use of the MGB in chickens under laboratory conditions resulted in a reduction in airsacculitis from 44% in nonvaccinates to 10% in vaccinates and further reduced the number of organisms present in the trachea post-challenge. Commercial chickens vaccinated subcutaneously midway or lower in the nape of the neck showed no untoward effects due to the bacterin. Those improperly vaccinated at the base of the skull developed a transient edema around the eye(s). This swelling did not appear to affect the performance of the chickens and had been reabsorbed by the next observation period. Subcutaneous inoculation should be at the mid or lower neck region. Field trials at a commercial egg operation comparing production efficiency showed that chickens vaccinated with the MGB had higher egg production, a greater percentage of eggs graded large and over, a smaller percentage of undergrades, and better feed conversion than chickens vaccinated with a live-culture, low-virulence Conn-F strain vaccine. The results of these studies indicate that the oil-emulsified MG bacterin is safe and highly efficacious.

Five polymorphic random amplified polymorphic DNA (RAPD) markers for 13 red raspberry (Rubus idaeus L.) and two purple raspberry (R. idaeus L. × R. occidentalis L.) cultivars were cloned and their termini sequenced. Sequence-specific 24-mer primer pairs were synthesized as extended RAPD primers and used in sequence characterized amplified region (SCAR) DNA analysis. All primer pairs generated polymorphic SCAR markers of the original RAPD marker sizes and length variants. Markers from four of the primer pairs could be easily scored and were adequate to identify the raspberry cultivars of the certification program of the province of Quebec.

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