Transforming tenderness and eating quality in tropical sweetcorn through introgression of tender germplasm

Abstract

The sweetcorn breeding program conducted by Queensland Department of Agriculture and Fisheries (DAF), has contributed significantly to the Australian sweetcorn industry by breeding hybrids that can produce standard sweetcorn for both processing and fresh consumption. The DAF program has focused primarily on tropical sweetcorn. Snowy River Seeds Ltd has one of the largest private sweetcorn breeding programs in the southern hemisphere and develops hybrids suitable for production in tropical, subtropical and temperate environments.

The most significant aspect of the tropical germplasm developed by DAF is better disease resistance compared to the tenderer, temperate germplasm. Tropical germplasm has bigger plant stature that makes is less efficient in terms of productivity. Quite often, tropical germplasm also requires longer growing periods making it less flexible in terms of planting and harvesting. There is very limited genetic variation for ear and cob related characteristics.

There is more genetic variability in terms of tenderness in temperate sweet corn than in tropical germplasm collections held by DAF. Introgression of tender Snowy River germplasm to the tropical gene pool should improve the chance of combining superior agronomy with improved eating quality. Combining improved eating quality with superior resistance to diseases e.g. northern corn blight (turcicum leaf blight), Johnson grass mosaic virus (JGMV), polysora rust (Puccinia polysora or southern rust) will be of significant benefit to the sweetcorn industry at Gatton, Bowen and in the Burdekin where temperate hybrids are the varieties of choice in the main part of the growing season. This project is aimed to develop tropical hybrids with significantly improved eating quality and disease resistance, thus expanding production areas and planting windows.