engleski

Inheritance of the early emergence of tassel in maize

Two accessions of the inbred line collection of domestic origin (Faculty of Agriculture, Zagreb) have very early emergence of tassel in regard to start of pollination (10-13 days vs. commonly 1-3 days). At the same time they have normal interval between pollination and silking. Performance of the early emergence of tassel (EET) would be desirable in hybrid seed production where in spite of the field variation one can wait for appearance of all tassels before any of them start to shed pollen. This would enable removal of all tassels at ones or through two passing. Inbred lines EET1 and EET2 were crossed with commercial inbreds of short interval between tassel appearance and pollen shed. After the analysis of segregating populations in respect to T-P interval, a bimodal distribution has been observed suggesting presence of one large effect gene contributing to large T-P interval when it is homozygous recesive. Within F2 population derived from EET2xB73 cross (n=508) the date of tasseling and date of pollination have been recorded for each individual plant, and than the T-P interval has been computed. From both tails of distribution 40 divergent F2 plants were selected (with extremely large and small T-P interval) for DNA extraction. “Bulk Segregant” analysis and ISSR markers have been employed to detect the DNA fragment which discriminates the F2 plants with large and small T-P interval. Detected EET co-segregating fragment was used as an RFLP probe in the F2 mapping population with more than 100 markers already mapped in. Mapping procedure revealed that the latter fragment originates from the chromosome no. 6. Fine mapping of the EET gene and finding its reliable marker has been undertaken. Since EET is recesively inherited trait finding a reliable genetic marker might significantly simplify and accelerate its introgression into commercial germplasm.

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nije evidentirano