利用品种混合控制小麦病害之研究进展

Advances of Research on Use of Cultivar Mixtures for Control of Diseases in Wheat

作物多样性在病害防治上的应用包括多系混合、品种混合和物种混合,其中品种混合策略备受重视。对于小麦,品种混合与它的组分净种时的表现相比至少有两方面的优势,即增加籽粒产量的稳定性和减少病害的危害．特别是对减轻锈病和白粉病的危害更为明显。但是,由于病害防治而获得的产量收益比较小．一般平均只有4％-5％。对于小种专化的病原物,小麦混合群体中复杂小种(能侵染两个或两个以上混合组分)的相对频率高于简单小种的情况并不少见,因此有必要实行小组分数目品种混合系统的多样化、增加组分之间的抗性差异或增加混合组分数目。影响品种混合防病效应的因素是今后需要大力研究的问题。

Crop diversity used for disease control includes multiline, cultivar and species mixtures. Cultivar mixtures have been put to more attention, and for wheat, such mixtures have shown at least two advangtages over their components in pure stands： improved yield stability and reduced severity of diseases, especially that of rusts and powdery mildew. However, yield benefits of the crop mixtures due to control of diseases appear to be small, generally being 4%-5% on average. It is not uncommon that in wheat cultivar mixtures, the relative frequency of complex races （races that can infect two or more components） of specialized pathogens is greater than that of simple races. Thus, diversification of mixtures within a small number of components, or increase in resistance differences between components and in component number in mixtures is needed. Research on factors influencing wheat mixture effects on diseases is also needed.