MATERNAL INDUCED HAPLOIDS IN RYE (SECALE-CEREALE L)

An inbred line of rye named P8 was found to possess haploid plants in their diploid stock. Phenomenon of spontaneous haploidy was examined i n this line. Fifty families derived from this inbred line were screene d to determine their ploidy level by mitotic chromosome count taking r oot tips. Seven families were found to contain haploid plants. Among t hese seven families, plants from two families which were diploid were crossed reciprocally with the standard out breeding cultivar Conrah. A s all of the tested plants of P8 were found 'aa' allele for 6-Phosphog luconic dehydrogenase (6-PGD) isozyme, therefore, only those Conrah pl ants which have 'bb' alleles for the same isozyme were used in crossin g programme. F1 seedlings were screened with the same isozyme marker a nd out of 1741 F1 seedlings tested, 51 were found to be non-hybrid phe notype for 6-PGD enzyme. Among these, only five plants were found hapl oid and the rest were diploid. Haploid plants were obtained only from those crosses where P8 was female which indicates that haploids in thi s line was maternally induced.