Alleles From Crop Wild Relatives Accumulated by Long-Term Adaptation to Low-Input Environments Contribute to Yield Advantages in Wheat (Triticum aestivum)

Summary

Increasingly variable climate conditions are affecting crop production, leading to greater yield fluctuations, which in turn are impacting global food security. Introducing alleles from regions where the expected stress conditions occur, so-called exotic alleles, could serve as a means to mitigate these effects. We examined the value of exotic alleles in four diverse populations constructed by the introgression of three resynthesized wheat lines using crop wild relatives. The four populations were cropped for 19 generations under conventional and organic farming system conditions, forming eight naturally adapted populations. Subsequent yield trials conducted over 3 years, parallel on conventionally and organically managed farms with distinct drought periods (2020, 2022 and 2023), revealed significant variation in yield levels and grain protein content. The yield was equal to or higher in the four organically adapted populations compared to the four conventionally adapted populations in both test environments.
However, the seed protein content was higher in the conventional adapted populations across both environments. Selection pressures imposed by farming systems might have driven divergent adaptation strategies in the populations, leading to the point where populations adapted to organic farming conditions were able to sustain prolonged drought periods of 40 to 80days during the vegetation period better than their conventionally adapted counterparts. The findings of this research emphasises that the selection of exotic alleles in low-input environments can result in more robust crop varieties.