II.1. Temperature and recombination values.
Sigurd Andersen and Kirsten Andersen. Agricultural Crop Husbandry and Plant Breeding, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, 1871 København V, Denmark.
Widely different recombination values are often reported for marker genes in barley. No explanation of this variation is known, but temperature during anthesis may possibly be of importance. In order to investigate this effect of temperature F1 plants from crosses between nematode-resistant barley and varieties with marker genes were moved from a greenhouse to growth chambers approximately one week before anthesis and kept there for 3 weeks. Counts made on 2462 F2 offspring gave the following results:
Previously published data from earlier trials by the present authors showed recombination values of 18.5, 24.6 and 11.9 respectively for these three crosses (Andersen & Andersen, 1973). The new values do not differ significantly from those previously obtained, although a recombination value of 17.4 in Ha2 x Lk is considerably higher than the previous value of 11.9. The chi squares in crosses with vt and log 1 were rather high, and a calculation of recombination for these two crosses is not completely correct. Although no final conclusion is possible, the data does not indicate any apparent effect of temperature on recombination values.
References:
Andersen, S. and K. Andersen. 1973. Linkage between marker genes on barley chromosome 2 and a gene for resistance to Heterodera avenae. Hereditas 73:271-276.
