Maternal induced haploids in rye (Secale cereale L.)

Abstract

An inbred line of rye named P8 was found to possess haploid plants in their diploid stock. Phenomenon of spontaneous haploidy was examined in this line. Fifty families derived from this inbred line were screened to determine their ploidy level by mitotic chromosome count taking root tips. Seven families were found to contain haploid plants. Among these seven families, plants from two families which were diploid were crossed reciprocally with the standard out breeding cultivar Conrah. As all of the tested plants of P8 were found ‘aa’ allele for 6-Phosphogluconic dehydrogenase (6-PGD) isozyme, therefore, only those Conrah plants which have ‘bb’ alleles for the same isozyme were used in crossing programme. F1 seedlings were screened with the same isozyme marker and out of 1741 F1 seedlings tested, 51 were found to be non-hybrid phenotype for 6-PGD enzyme. Among these, only five plants were found haploid and the rest were diploid. Haploid plants were obtained only from those crosses where P8 was female which indicates that haploids in this line was maternally induced.