Accelerated Domestication of New Crops: Yield is Key

Abstract

Sustainable agriculture in the future will depend on crops that are tolerant to biotic and abiotic stresses, require minimal input of water and nutrients, and can be cultivated with a minimal carbon footprint. Wild plants that fulfil these requirements abound in nature but are typically low yielding. Thus, replacing current high-yielding crops with less productive but resilient species will require the intractable trade-off of increasing land area under cultivation to produce the same yield. Cultivating more land reduces natural resources, reduces biodiversity, and increases our carbon footprint. Sustainable intensification can be achieved by increasing yield in underutilized or wild plant species that are already resilient but achieving this goal by conventional breeding programs may be a long-term prospect. De novo domestication of orphan or crop wild relatives using mutagenesis is an alternative and fast approach to achieve resilient crops with high yield. With new precise molecular techniques it should be possible to reach economically sustainable yields in a much shorter period of time than ever before in the history of agriculture.

FIND-IT: Accelerated trait development for a green evolution

“…In the future, FIND-IT opens up new opportunities for crop improvement by providing a means to select and incorporate domestication traits into the approximately 7000 undomesticated or semidomesticated crop plants that have superior drought tolerance, water tolerance, disease resistance, and mineral use efficiency, including perennials or wild crop relatives ( 48 , 49 ). It also has potential for the introduction of valuable gene alleles found in exome collections and pan-genomes ( 9 , 50 , 51 ) and improved variants designed and identified in vitro.…”

The next era of crop domestication starts now

“…While some traits desired in our future crops will certainly be species specific, others should be universally sought after. Unmet needs and examples of related traits that could be addressed in domestication pipeline strategies ( 108 , 143 ) include: increased ecological benefits such as for soil health, by targeting carbon sequestration and perenniality, and for biodiversity, by targeting pollinator services and habitat stability and complexity; decreased reliance on inputs, by targeting nitrogen production and efficiency and pest and pathogen resistance; hardiness in the face of climate variability and weather extremes, by targeting water use efficiency and cold and heat tolerance; adaptation for degraded, detrimental, and novel environments, by targeting carbon sequestration, length of life, and/or salt tolerance; fit of the crop into innovative and valuable cropping systems and rotations (with other plants, microorganisms, etc. ), by targeting growth habit for harvestability, resource partitioning traits, micronutrient and high protein content for human use, and multipurpose uses along with human food, such as fiber, lumber, forage, medicine, or fuel; fit of the crop into more resilient and sustainable supply chains and food economies, by targeting storability and durability of the harvested crop, including nutrient content and retention.…”

“…For underutilized species, breeding targets will likely include traits that are important to scaling up cultivation, such as productivity, reproductive synchronicity, palatability, harvestability, and durability/storage capacity ( 143 ). But, in order to ensure we do not repeat the missteps of past domestication efforts, we must be more intentional.…”

“…Selection on new domesticates can target novel uses and innovative cultivation schemes, but it must also consider downstream needs, such as harvestability, storage capacity, and nutrient retention ( 143 ). Furthermore, breeding programs must select for limited tradeoffs between stress tolerance and yield, a goal that may be best accomplished by domesticating species that are already adapted to the environmental/climatic conditions in which they will be cultivated ( 143 ).…”

“…Selection on new domesticates can target novel uses and innovative cultivation schemes, but it must also consider downstream needs, such as harvestability, storage capacity, and nutrient retention ( 143 ). Furthermore, breeding programs must select for limited tradeoffs between stress tolerance and yield, a goal that may be best accomplished by domesticating species that are already adapted to the environmental/climatic conditions in which they will be cultivated ( 143 ). Careful attention should also be paid to maintaining genetic diversity, including cryptic variation (i.e., not observed/expressed in domesticates) and that of important polygenic traits such as pest and pathogen resistance ( 181 ).…”