Rebetzke, G. J.; Richards, R. A.; Sirault, X. R. R.; Morrison, A. D.
Abstract:
Lack of moisture near the soil surface commonly delays sowing, reducing grain yields of Australian wheat (Triticum aestivum) crops. Deep sowing would allow growers to make use of soil moisture lying below the drying topsoil, but the short coleoptiles of semidwarf wheats reduce emergence when sowing at depths greater than 5 cm. Selection of longer, thicker coleoptiles would help in improving emergence in hard or crusted soils, or when deep sowing, yet little is known of genetic control of coleoptile size in wheat. A diallel mating design was generated from crosses between 12 Australian and overseas wheats, and assessed for coleoptile size at different temperatures (11, 15, 19, and 23�C). Repeatabilities for coleoptile diameter and length were moderate to high on an entry-mean basis (R