Genetic studies on the resistance to NPV in silkworm ( Bombyx mori L.)

In an experiment with 10 original races and 2 hybrids of silkworm (Bombyx mori) probit analysis was made to study the resistance of different silkworm races to NPV (nuclear polyhedrosis virus). Highly significant differences were found to exist between the races/hybrids in their NPV resistance. Such a resistance was shown to be controlled by minor genes and exhibited a patroclinal tendency in its inheritance. Japanese races appeared to be more resistant to NPV than Chinese races.