A COMPARISON OF MALE AND FEMALE RECOMBINATION FREQUENCY IN WHEAT USING RFLP MAPS OF HOMOEOLOGOUS GROUP-6 AND GROUP-7 CHROMOSOMES

A novel approach was used to compare male and female recombination rat es in wheat. Doubled haploid lines were developed from an F-1 using tw o distinct approaches: the anther-culture technique and the Hordeum bu lbosum system, from which sets of lines were developed from ''male'' a nd ''female'' meioses, respectively. The genotype of the lines was est ablished at RFLP and isozyme markers polymorphic on chromosomes of hom oeologous groups 6 and 7, and ''male'' and ''female'' linkage maps wer e calculated using this information. The markers in one segment of chr omosome 6B exhibited disturbed segregation frequencies in the anther-c ulture population. The ''male'' and ''female'' maps differed significa ntly in recombination frequency between some markers on two chromosome s, and these were consistent in direction within chromosomes and incon sistent in direction between chromosomes. In two of the four chromosom es studied the ''male'' map was much longer than the ''female'' map. T hese results suggest that significant differences may exist in male an d female recombination frequencies in bread wheat which are specific t o certain chromosomal segments but are inconsistent in direction betwe en chromosomes. Other factors, such as environmental influences, may a lso be important in creating differences.