Third supplementary list of wheat varieties classified according to their genotype for hybrid necrosis

Summary New data about the geographical distribution of necrosis genes support the previous conclusion, viz. the Old World can be divided by a rough line running through the Mediterranean and Black Sea countries to Lake Baikal and from these to northern Japan. The Ne ₁-area lies south and east and the Ne ₂ area north and west of this line. There are indications that Ne ₁-carrying wheat varieties exist in the Leningrad district.The third supplement contains 441 varieties and selections of which the genotype for hybrid necrosis is given. The total number of tested varieties etc. is now 1150.