Validating the Use of Vegetation Indices to Select Nitrogen Use Efficient Wheat.

Few breeders evaluate bread wheat (Triticum aestivum L.) lines for nitrogen use efficiency due to the high cost of labor, time, and supplies needed. However, it has been demonstrated that proximal sensing of vegetation indices can be used to select wheat with improved nitrogen use (NU) traits. This proximal sensing process is much cheaper, easier, and faster than traditional methods of measuring NU traits. Therefore giving wheat breeders a new tool to select for difficult to measure traits. Our previous research has shown that the vegetation indices, Boochs2 and Maccioni, performed consistently across environments and were significantly related to the wheat NU traits nitrogen harvest index, post anthesis nitrogen uptake, and grain nitrogen yield. To validate these results, we selected 60 sibling pairs from a wheat F5 nursery where one sibling had a high index value (indicating good NU phenotype) and one sibling had a low index value (indicating poor NU phenotype). The trial was grown in 2014 and 2015 in Ithaca, NE under low and moderate N conditions. Based on these trials, we show that selections based on vegetation indices are heritable and therefore useful to the breeder.