engleski

Evaluation of nitrogen use efficiency in the Maksimir 3 Synthetic maize population

Nitrogen use efficiency (NUE) has become an important trait for sustainable agriculture. Traits adaptive to nitrogen-limited environments present in maize landraces could not be easily implemented directly into modern maize breeding programs. Thus, the landraces might be improved by recurrent selection and intercrossed to form synthetics from which new lines could be derived and used as sources of certain traits for elite breeding material. The Maksimir 3 Synthetic (M3S) maize population was created from landraces traditionally grown under low levels of soil fertility. The synthetic was subjected to recurrent selection for yield and disease resistance during three cycles and, in addition for NUE, in the fourth cycle. In order to determine the effect of four cycles of recurrent selection, we evaluated each population per se, their testcrosses and S1 progenies under high and low nitrogen input conditions at four locations during 2010. The populations per se and their testcrosses had on average higher, values of grain yield (+21%), kernel row number (+3%), plant height (+9%), ear height (+15%), kernel depth (+5%), ear length (+6%), ear diameter (+4%), and ear leaf chlorophyll content (+30%) at the high nitrogen fertilization rate relative to the low nitrogen rate. The S1 progenies responded similarly to nitrogen fertilization. The genotype x nitrogen interaction for yield was not significant and no specific adaptation to the nitrogen deficient environments. After four cycles of recurrent selection, significant increases in grain yield were found at both levels of nitrogen fertilization.

maize; nitrogen use efficiency; recurrent selection

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