光照因素对水稻品种苗期褐稻虱抗性的影响

 在人工气候箱及温室自然条件下研究了光照对品种抗性、植株生势及耐害性和褐稻虱生存、发育的影响。光照不足造成品种苗期抗性减弱甚至丧失，其原因是由于植株的生势减弱导致受飞虱为害后的补偿能力下降。中抗品种耐害性丧失和抗级品种的拒虫性减弱。在短光照生长条件下和长光照条件下，飞虱取食高抗品种的植株，其吸食量若虫生存率和发育进度，均无显著差异，表明高抗品种的抗生性在短光照条件下仍能保持。短光照条件下．如果接虫前或后予以充足的光照条件，或将接虫秧龄提高到4片叶，品种的抗性水平则可保持。

Influence of Light Duration and Intensity on the Resistance in Rice Seedling to the Brown Planthopper

Abstract: As the rice seedlings were grown into the 3-leaf stage under unsuitable light condition, the moderately resistant varieties lost the resistance and the resistant varieties exhibited a decline in resistance.This decrease in resistance might be induced by these factors: (1) The growth vigour and compensatory ability of plants became weaken; (2) The tolerance in moderately resistant varieties lost; (3) The nonpreference in resistant varieties disappeared.The light condition did not affect the antibiosis,as demonstrated by the fact that the amount of honeydew excreted,survival and development of BPH nymphs fed on the resistant varieties showed the same level between the light treatments.However,before or after infestation when the seedlings were grown under a suitable light condition,the decrease in resistance could be prevented.When the plants were grown under weak light,resistance at the 4-leaf stage was higher than at the 2-leaf stage.