Increasing boron efficiency in international bread wheat, durum wheat, triticale and barley germplasm will boost production on soils low in boron

Boron deficiency causes grain set failure and yield loss in many of the world's wheat growing countries. We suggest growing B efficient genotypes as a means to overcome the problem. This study evaluated international germplasm of bread wheat (Triticum aestivum L.), durum wheat (Triticum durum Dest.), triticale (Triticosecale Wittmack) and barley (Hordeum vulgare L.) for B efficiency. The first set of germplasm consisted of bread wheat, durum wheat and triticale from CIMMYT 1996/1997 nurseries and a B efficient check wheat cv. 'Fang 60'. The lines were grown in the field on soil with 0.1 and 0.2, and 0.3 mg HWS B kg(-1) for durum wheat and triticale. The grain set index (GSI, percentage grain set in the first two florets of 10 central spikelets) measured B efficiency in wheat, durum and triticale genotypes without the need for a B sufficiency control. Three-quarters of the lines tested were B inefficient, which included all of the durum wheat, 84% of the triticale and 60% of the bread wheat lines. Six of the bread wheat lines evaluated were in the same B efficient class as Fang 60. The response to low B was confirmed in a sand culture experiment without added B. Similarly high frequency of B inefficiency was found in a second set of germplasm which included bread and durum wheat, barley and triticale lines from CIMMYT and ICARDA 2000/2001 international nurseries. Incorporating the B efficiency trait in germplasm such as these, would ensure their adaptation to low B soils, and so enable their genetic potential to be fully realized in some of the world's difficult production areas. (C) 2003 Elsevier B.V. All rights reserved.