Production of mutants exhibiting cold tolerance in spring canola (Brassica napus)

A major factor affecting spring canola (Brassica napus) production in Canada is cold temperatures and killing frosts during seed development or during seed maturation. The objective of this study is to produce mutations in vitro that have altered biochemical pathways that increase cold tolerance. To enhance the understanding of cold stress in canola in the cold-induced oxidative stress pathway, mutants with elevated levels of key defense signaling molecules salicylic acid (SA) and jasmonic acid (JA) were produced using UV light. In addition, mutants that overproduce proline were produced, which is known to protect plant tissues in the cold-induced osmotic stress pathway. There were nineteen out of the seventy-four mutants tested in the final controlled environment indoor freeze test identified with significant cold tolerance compared to their donor parents. Two proline selected mutants, 997-48 and 997-71 both had greater survival percentages in winter field trials over multiple years as compared to parental and winter checks. Development of increased frost tolerant cultivars should allow for spring canola to be produced in western Canada without compromising seed quality.