Association Mapping of Heat Stress Tolerant Traits of Canola (Brassica napus L.).

Brassica is a cool season crop and is susceptible to high temperatures. Developing heat stress tolerant varieties helps the crop to sustain in growing temperatures and to extend the geographical range of cultivation. We phenotyped 85 spring type Brassica napus accessions grown in the field with natural heat stress at the end of flowering to pod initiation stage. An association mapping study was performed to identify QTL associated with heat stress tolerance traits such as plant height, main raceme height, pods per main raceme, pod length, and pod abortion per main raceme. About 37k markers obtained using GBS were used for this study. Multiple markers distributed on most of the chromosomes were identified. Further, 21 QTL regions were identified for all the five traits. Multiple candidate genes known to be involved in stress, abortion of different organs were identified in the vicinity of the QTL.