Studies of a Gametophyte Factor in Barley

Abstract

1. Two sib plants of barley both possessing the genotype Wx Wx Ac2 ac2, when crossed with wx wx Ac2 Ac2, gave significantly lower ratios for wx than expected in F2. The average percentages of the recessives in the F2 were 20.5% for wx and 24.1% for ac3.2. In F3, the ratios for waxy could be classified as belonging to 3 groups, i.e., ‘low’, ‘normal’, and‘high’, the average percentages of wx being 18.1%, 24.8%, and 31.9%, respectively. Wx Wx Ac2 Ac2 lines were established which, when crossed to a normal wx tester, produced low wx ratios in all the F2 progenies.3. The distorted ratios for wx and the breeding behavior are explained best by assuming a gametophyte factor Ga linked with the Wx locus in the Ac2 ac2 stock.4. The recombination value between the Wx and Ga loci was estimated to be approximately 33% from the F3 data.5. The relative functioning of the Ga-pollen versus ga-pollen was estimated as 90.6%:9.4%.6. The wx and ac2 genes in F2 progenies from Ga ga plants showed 43.8±1.3% recombination, whereas in progenies from ga ga plants they were independent. The order of the 3 loci is either Wx-Ga-Ac2 or Ga-Wx-Ac2.7. Stocks, that have Wx Wx Ac2 Ac2 Ga Ga, have been established.