Monday, November 13, 2006

“Tuning up” Grain Shattering Evaluation Methods in Spring Wheat.

Guorong Zhang and Mohamed Mergoum. North Dakota State Univ, Plant Science Dept, Loftsgard Hall, P.O. Box 5051, Fargo, ND 58105-5051

The use of exotic germplasm to incorporate Fusarium head blight (FHB, caused by Fusarium graminearum Schwabe) resistance into adapted wheat (Triticum aestivum L) has recently raised the importance of grain shattering. This study aimed to develop and identify efficient and reliable evaluation methods for grain shattering in spring wheat. Four field and two laboratory methods, were elaborated, tested 24  wheat genotypes in five environments. The results showed that grain shattering under field conditions was significantly affected by environmental conditions. The field methods including, field grain shattering (FS) and grain shattering from spikes (SS), had large coefficient of variation (CV) and were not highly consistent across environments. Among the field methods, the SS method might be the most useful method due to its relatively high Range/LSD0.05 and cost efficiency. All the field methods require favorable environment conditions and are time consuming. Laboratory methods, induced random impact (IRI) and glume strength (GS) tests, were moderately correlated with field methods. However, these methods were relatively environmental independent. High consistency across locations and years were observed. In addition, only small sample size was required for laboratory methods. It indicates that laboratory methods could be more efficient than field methods. Therefore, they could be of interest for researchers to indirectly screen for grain shattering even without the environmental conditions conducive to grain shattering. The IRI method is more promising than GS because of its stronger correlation with field methods in general.