Soil salinity is a major challenge to agriculture, causing an estimated $27.3 billion in economic losses globally each year. Over 20% of irrigated land suffers from soil salinity, and changing precipitation patterns as well as rising sea levels associated with climate change are predicted to exacerbate these problems. Yet, in Brassica rapa, an economically important crop that includes seed pressed for vegetable oils, Chinese cabbages, bok choy, turnips, and turnip greens, relatively little is known about the effects of soil salinity. UN FAO recommendations for B. rapa soil salinity tolerance are based on just a few genotypes and do not incorporate genetic information, which means they are of limited utility. Existing scientific laboratory studies often focus on just germination or early growth, while field studies tend to apply salt treatments after germination and only look at yields. Here, we examine the effects of soil salinity on 188 fully sequenced genotypes of B. rapa generated by crossing an oil seed with a bok choy. Soil salinity treatments were imposed prior to germination and continued throughout plant development. We determined that critical plant traits such as germination and flowering time were delayed in response to soil salinity and that variation in these traits was heritable, indicating that they are genetically based and could be selected upon and improved. We then utilized Quantitative Trait Mapping to identify the genomic loci that control these traits and found that these loci differ among treatments, implying that there is strong genetic-by-environment interactions that must be considered during any crop development program.
Authors: Sarah Niesen, Abigail Kozyra, Logan Mather
Faculty Advisor: Rob Baker, Department of Biology
You must be logged in to post a comment.