Heterosis of juncea canola under terminal drought conditions

Abstract

To determine the levels of heterosis in F1 hybrids of juncea canola under well-watered and water deficit conditions, glasshouse experiments were conducted at the University of Melbourne, Parkville campus between 2012 and 2014. Three juncea canola hybrids, their parents and an open-pollinated juncea canola control cultivar (OasisCL) were grown. Plants were subjected to two treatments—well-watered and water deficit after first open flower to maturity. Measurements were recorded on days to various phenological stages, biomass production, seed yield and yield components. Yield heterosis was determined as superiority of F1 hybrids over mid parent and better parent. Two juncea canola hybrids—HJM1Z-2013 and HJM1Z-0027 out-yielded OasisCL and showed significant mid parent and better parent heterosis for seed yield under water deficit. Number of pods per plant was the major yield component affected by water deficit whereas seeds per pod, thousand seed weight and harvest index were stable. Water deficit had significant negative effects on biomass production at harvest. The study revealed the possibility of exploiting yield heterosis of juncea canola under terminal drought conditions. However, further experiments are recommended to verify the results as the results were from pot experiments in controlled conditions.