Pulses, annual leguminous crops that include lentils, beans, peas and chickpeas, have nutritious value as a low-fat source of protein and fiber.
They help to increase soil fertility by virtue of their nitrogen-fixing properties, and generally have a lower water footprint compared to most other protein sources.
As valuable as current pulse varieties are, however, it is essential that pulses continue to be improved to become productive and resilient enough to meet the challenges of the 21st century, including population growth, climate change and land degradation. This article describes the potential of an often-overlooked resource for pulse improvement: their wild relatives.
Past and current use of Crop Wild Relatives in pulse improvement
Crop wild relatives (CWR) are wild plant species that are related to cultivated crop species. Many CWR can be bred fairly easily with the crop species to which they are related. They represent a valuable resource for crop breeding, since CWR contain useful genetic diversity, some of which is not present in cultivated crops.
The United Nations General Assembly has declared 2016 the “International Year of Pulses” in recognition of their critical contributions to global food security.
CWR have been used by breeders to develop new crop varieties for decades, particularly in the wheat, tomato, rice, and sugarcane genepools. However, the past use of CWR species for pulse improvement has been limited. Some initial work has taken place using wild relatives of soybean, cowpea and Phaseolus (beans) to breed cultivated varieties with resistance to pests and diseases. In addition, wild chickpea species Cicer reticulatum has been used to develop a chickpea variety with greater drought and temperature tolerance (BG1103) that has met with great success in Northern India, yielding approximately 40% more than competing cultivars, and disease resistance has also been identified in several wild relatives of chickpea.
Additional work to improve chickpeas and lentils using their wild relatives is currently underway as part of the project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives,” jointly managed by the Global Crop Diversity Trust and the Royal Botanic Gardens, and Kew, and supported by the Government of Norway. The Trust is also funding pre-breeding efforts that use wild pigeonpea, grasspea and Phaseolus (bean) species.
The lentil team, coordinated by the University of Saskatchewan in Canada and the University of Leon in Spain, is working to hybridize cultivated lentil with three wild lentil species to identify sources of resistance to Orobanche (or broomrape), stemphyllium blight, and drought tolerance. The goal of the work is to make available genes for disease resistance and drought tolerance to breeders to help increase the resilience of lentil production worldwide and contribute to global food security.
The chickpea team includes scientists at the University of California, Davis, and Florida International University in the United States; Dicle University, Harran University, and the Aegean Agricultural Research Institute in Turkey; and the International Center for Agricultural Research in the Dry Areas (ICARDA) in Morocco. The primary goal of the chickpea work is to evaluate collections of the two wild progenitor species of cultivated chickpea for drought tolerance, with the goal of contributing to abiotic stress tolerance and ultimately releasing climate-resilient crop varieties.
Pulse improvement and landscape resilience
Using CWR to improve cultivated pulse varieties can help to increase the resilience of the production of these important food plants. The wild relatives of domesticated pulses possess a wide range of useful traits that can help to strengthen income generation and food security among the smallholder farmers who cultivate them, including drought tolerance, pest and disease resistance, and water efficiency. In the face of climate change, these improved varieties will be particularly useful.
In addition to the farm-level benefits, using CWR to create new pulse varieties has great potential to bolster the resilience of the larger landscape as well. The use of a more water-efficient pulse variety can benefit producers living in arid regions affected by land degradation that has made water even scarcer. Increasing the productivity and profitability of pulse cultivars can make their cultivation more attractive to farmers in a given region, helping to boost soil fertility across the landscape as farmers switch away from other crops to nitrogen-fixing pulses. And developing drought-tolerant and disease-resistant pulse varieties can help to prevent or mitigate the impacts of famine in the case of droughts or disease epidemics.
Pulses have great promise to improve the livelihoods of smallholder farmers, provide better nutrition in rural areas, and rehabilitate degraded soils. The use of CWR to improve pulses has the potential to ensure that pulses can contribute even more fully to food security and landscape resilience in the 21st century. Investments will need to be made now to conserve and use pulse CWR, however, if these future benefits are to be enjoyed.
Visit CWR Diversity to learn more about the project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives”
The use of wild relatives in crop improvement: a survey of developments over the last 20 years
Increasing the climate resilience of chickpea varieties
Using wild lentil species to increase drought tolerance and disease resistance
Nik Tyack has worked to assist the Global Crop Diversity Trust with communication efforts associated with the project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives.” He is currently researching the economic value of Czech crop diversity through a Master’s program in economics at Charles University in Prague.