Evidence of simple genetic control in potato of ability to restrict potato leaf roll virus concentration in leaves.

The concentration of potato leaf roll virus (PLRV), measured by quantitative enzyme-linked immunosorbent assay, in foliage of plants of cv Maris Piper and clone G7445(1) with secondary infection was 2,700 ng/g leaf and 120 ng/g leaf, respectively. In experiments to examine the genetic control of their ability to restrict the multiplication of PLRV, reciprocal crosses were made between these two clones. Among 40 genotypes from the progeny of the crosses, about half had a low PLRV concentration in plants with secondary infection and the other half had a high concentration. The possibility of monogenic control of the character that restricts PLRV multiplication in such clones of Solanum tuberosum is discussed.

Establishment of two group practice centres by conversion of existing houses.

A practice of five (later six) doctors established their own group practice centre by purchase and conversion of an existing house. Later a second, smaller centre was established in the same way to replace an existing branch surgery.The planning, financing, and execution of these projects is described.