Rather than digging up thousands of plants in the field to measure their root systems - a costly, and tedious process - markers in the lab could quickly indicate the plants most likely to contain the deep-rooting genes.
(tedious process - markers in the lab; could quickly indicate; the plants most likely to contain the deep-rooting genes) (the plants most likely; to contain; the deep-rooting genes)
tedious process - markers in the lab the plants most likely
could quickly indicate to contain
the plants most likely to contain the deep-rooting genes
the deep-rooting genes